The solo enthusiast versus the club member

Filming a silver birch wood recently a passer by enquired why, as the trees were devoid of foliage and looked rather ugly. The reply given was that some of the footage would be used to support a discussion on a pending bonsai article. As the conversation developed, he remarked that he had always been interested in bonsai and would like to know more about the art, now he had retired. “Are there any bonsai clubs or associations where one can join?” Unfortunately there are no bonsai clubs in this area that I am aware of was the reply. “That is a pity, bonsai are sold locally in garden centres and stores so there must be some interest.” Yes you are probably correct in your assumption, but it really is up to the individual whether he or she wants to be part of a club or stay as a solo enthusiast.

The solo enthusiast

For my part being a member of a club was not an option when my interest in bonsai began in the mid 1970s because, (a) my work meant much travelling with long periods away from home. (b) There were no clubs or associations in my then vicinity where one could gain the much needed knowledge. (c) Not having permanent roots and leading a nomadic existence is another factor. These are the reasons for remaining a solo bonsai enthusiast. Moreover, it can be argued that there is not much you can achieve as a club member that you cannot do as a solo enthusiast; you just have to work a lot harder.

Meaning that to gain bonsai knowledge, one has to immerse ones self in plenty of research for example. The attributes of a particular species of tree/s you may have and how to care for it or them, when to feed and what kind to use, when to prune and when to wire, preventing or eradicating pests and disease and the type of soil composition to use. At that time there were a few horticultural books and magazines to shed some light on these subjects, but there was no world wide web as we have today, so much of the work done was mainly trial and error.

However, now there are countless bonsai clubs and associations world-wide many accessible via the world wide web. All offering tips, tricks and advice from both the novice and the experienced through written text and production of video presentation, many of which can be found on Youtube – some good, some bad and some indifferent. The problem is that it takes time to trawl through it all to find what is relevant to ones needs without getting side tracked, which can be a real pain in the rear or a learning curve depending on how you approach the task.

Arguably the world wide web is very useful in that with one click of the mouse button, here is a site that has everything you need. From pre-bonsai specimens, soil compositions and fertilizers, ceramics, training pots, tools, various gauges of wire both copper and aluminium, cut pastes and wound sealants etc. But just going on line and purchasing what you think you need for example, a ready-made tool kit can be expensive, (100€ to 300€) only to find that improvisation using some standard DIY tools can reduce the cost considerably.

Another bone of contention is finding a reputable supplier who may not be in your area and the down side is the cost of postage, because bonsai equipment especially ceramics are relatively heavy. One can bargain for discount but, you usually have to purchase more than you need to get this. With ceramics, you see a pot listed that is presumably ideal for your tree, but when it arrives via the post it does not resemble its advertised picture. It looks awful when associated with your tree – now you are stuck with a pot you don’t want having paid good money for, which is now redundant – a hard and expensive lesson.

The club member

Being a member of a club or association, can reduce much of the hard work a solo enthusiast has to endure due to the pooled knowledge. For example one is able to receive information on the following subjects.

  • Care and general maintenance of bonsai

  • Advice on soil compositions and fertilisation

  • Styling, wiring and pruning, applying jin or sharimiki and uro

  • Prevention against pests and disease, how to make horticultural soaps

  • How to make basic tools and turntables via improvisation

  • Ceramics, how to choose the correct shape, size and colour

Moreover, a club is able to purchase different gauges of wire in bulk that can be sold at cost saving money. Initiate agreements with a supplier/s for example, the sale or return of ceramics and tools for either hand or power use. In addition, field trips can be organised, lectures and demonstrations from the experienced can be arranged. These are just some of the many advantages a club or association member has over the solo enthusiast.

What does it take to start a club?

It all depends on the level you want to start at, jumping in at the deep end will cost money you cannot recuperate. Stating off small is much easier, a few friends and or colleagues meeting once a month at a members house or apartment is a good way to start, failing this a coffee house or tea room will suffice. Advertising is always a headache and can be expensive especially if using the local press. One way to solve this is by word of mouth, putting adds on shop notice boards and if possible garden centres.

Another way is to make a web site, one does not need a degree in computer technology to achieve this as there are ready-made uncomplicated sites, able to accommodate your immediate needs. Such sites can be had for under 20€ for a years subscription and it is a way of putting the word out; getting known. Another consideration is to make a public presentation as an incentive to motivate new members to join. Such a presentation should be made by a member, preferably one with bonsai knowledge. The presentation should be short (10 mins) with time for questions and answers in addition, there should also be bonsai trees on display to aid the incentive.

Immediate needs

The club will need a chairman/woman to start and chair the meetings, which should be kept to a minimum leaving the majority of the allotted time for members to integrate. A secretary/treasurer who deals with the status quo and any new developments. All relative information can be channeled back to the members via email, rather than a printed format, which can be expensive and time consuming. A bank account for subscriptions and payments, the former to be agreed upon by the members.

As the club grows a venue will need to be found, preferably one free of charge, or one at low cost, because this is relative to the amount of each member’s subscription. Meaning, 12 x the monthly hire cost divided by the amount of members. A venue is important because it facilitates the need to accommodate such activities as discussions and demonstrations on bonsai horticulture, it also allows for members to meet and greet and share their knowledge. The exchanging of plants, cuttings and seeds, ceramics and other appropriate items, thus the club or association becomes a family.

A personal perspective

As stated, the bonsai club does have advantages over the solo enthusiast, but there is a more appropriate reason for its existence and it is for the following reason.

As we know nothing in this world lasts forever, even us mere mortals are part of the cycle of life. Our bonsai if cared for properly will undoubtedly out last us, but what then becomes of them once we shed our mortal coil. Will all the hard work, time and effort go to waste if homes cannot be found for them. Arguably one can sell them at auction where they are cared for by ‘green-fingered’ enthusiasts, which is the norm, but what actually happens to them is any ones guess. Going down this path fills me with trepidation, because those professing to be knowledgeable when they are not leaves a bitter taste in the mouth. What is more appropriate is to donate a bonsai collection to a club where they can be distributed among the members, whom will care for their health and continued development, which is a more appealing course of action.

The long dark cold days of winter are fading from memory as spring approaches, which for the bonsai enthusiast is when life begins anew, a time where our enthusiasm in bonsai is rekindled, not that it was ever diminished. It matters not whether one has only an indoor bonsai so called because of their temperate characteristics, a hardy outdoor species or a collection of both, the learning curve begins again. As stated the solo enthusiast has much work to attend, whereas the club member can reduce this considerably. Nonetheless, whatever your chosen path, success in your endeavours as bonsai enthusiasts is always tantamount. Until next time BW, N.

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Toxic Bonsai Part IV

Toxic Bonsai Part IV

Umbrella tree (Queensland)Schefflera actinophylla. Family Araliaceae. Is an evergreen tree that grows to 15m (49ft) tall, native to the tropical rain forests of New Guinea, Java and Australia’s eastern Queensland. This decorative tree when mature, produces racemes up to 2m (6.5ft) long with an abundance of small dull red flowers beginning in late spring. Schefflera actinophylla is considered to be an aggressive plant prolific in growth, hence the reason why it is an uncommon specimen in bonsai collections. Schefflera actinophylla does contain toxins, but these are not considered to be dangerous to humans. Ingesting the leaves can cause mouth tingling and numbness, vomiting and abdominal pain and sap when in contact with skin can cause irritation and rash.

Umbrella treeSchefflera arboricola. (syn. Heptapleurum arboricolum) also a member of the Araliaceae family is native to Taiwan, but can be found world-wide as a house plant and also in bonsai. S. arboricola should not be mistaken for S. actinophylla, because of the height difference. Moreover, S. arboricola has different leaf colour and patterns some variegated with cream to white flowers with yellow edges or centres although much depends on the individual cultivar. S. arboricola is poisonous and carries the same toxins as S. actinophylla and leaf consumption can cause mouth tingling and numbness, vomiting and abdominal pain and sap when in contact with skin can cause irritation and rash.

ViburnumLantana. Family Adoxaceae. Also known as the ‘wayfaring tree’ is a deciduous shrub native to Europe, but can be found in Asia and northern Africa and is a relatively common specimen in bonsai. Its oval dark green leaves have a downy or hair like covering on the underside and flowers that are creamy white in colour and green fruit, which ripen to a bright red eventually turning black when mature. The berries if consumed although mildly toxic can cause vomiting, diarrhoea and abdominal pain if ingested in large quantities.

ViburnumOpulus. Family Adoxaceae. Is often referred to by its common name the ‘Guelder rose’ and is native to Europe, northern Africa and central Asia. This deciduous shrub has three lobed leaves that are opposite to each other having an appearance similar to maples. The flowers in clusters are white in colour with their centre being fertile surrounded by an infertile ring that are produced in early summer and fruit that is bright red. The berries if consumed although mildly toxic can cause vomiting, diarrhoea and abdominal pain if ingested in large quantities.

Virginia creeperParthenocissus quinquefolia. Family Vitaceae. Is native to north America, Canada, Mexico, Guatemala and Europe. It is a prolific deciduous climbing vine reaching heights of over 30m (100ft) and attaches itself to smooth surfaces by small adhesive pads. This plant normally seen growing on the sides of buildings has striking colours throughout the seasons, the leaves change from various greens to yellow to orange to red and purple and this colour change makes the species attractive to bonsai. The flowers are small and greenish white in colour, which change into purple/black berries in the autumn. The sap, leaves and berries are poisonous because they contain the toxin oxalic acid, prolonged skin contact can be dangerous and ingesting any part even small amounts can cause kidney damage and death to humans.

White cedarSpp. Family Cupressaceae. Include Chamaecyparis thyoides – Atlantic white cypress, Cupressus lusitanica – Mexican white cedar, Thuja occidentalis – Northern white cedar, Thuja plicata – western red cedar and Cryptomeria japonica – Japanese cedar. Cedars are conifers and are found in many parts of the world, from northern climes to temperate zones. They have many uses for example, grown as barriers, wind breaks, dense hedging in parks and gardens and are a common species in bonsai. However, all cedars carry toxins the primary irritant being plicatic acid and some are more potent than others for example, the western red cedar and Japanese cedar have the highest content. Exposure to plicatic acid can cause severe asthma, rhinitis or conjunctivitis, that can be progressive. In addition, plicatic acid in contact with skin can cause a hypersensitivity reaction, a type of response seen in tuberculin skin tests.

WillowSalix alba. Family Salicaceae. Is a species native to Europe but is also found in western and central Asia and within this genus are: Salix alba Vitellina – a willow with yellow shoots and Salix alba var. Britzensis, Cardinal and Chermesina having orange to red shoots. The willow a medium sized deciduous tree can be in a weeping form or with a dome shaped crown with long thin leaves pointed at the end. (5–10cm long x 0.5–1.5cm wide) It is often found in bonsai in designs that include slanting (Shakan) and (Fukinagashi) wind swept. Male and female trees each produce their own flowers in the form of catkins that appear in the spring and when mature are wind pollinated. However, the willow contain salicylate toxins in the bark that if ingested can cause the following. Ulcers, nausea, vomiting, stomach bleeding, kidney inflammation, tinnitus and skin rash.

WisteriaSpp. Family Fabaceae. Includes various species of climbing bines (Plants that climb by their shoots) Wisteria brachybotrys, Wisteria brevidentata, Wisteria floribunda, Wisteria frutescens, Wisteria macrostachya, Wisteria sinesis, Wisteria venusta and Wisteria villosa. That are predominantly native to the eastern north America, China, Japan and Korea. Although these species are found in bonsai, arguably the most common is the Wisteria sinesis that when in bloom has a striking floral display for example. The great wisteria at the Ashikaga flower park in Tochigi, Japan, which covers more than 1,990 square meters over half an acre. Wisteria flowers are between 10 to 80cm in length and produced in pendulous racemes and are either purple, violet, pink or white. All parts of the wisteria are poisonous they contain the toxin saponin and if ingested the symptoms are: nausea, vomiting, abdominal pain, diarrhoea, severe gastroenteritis, dizziness, confusion, speech problems and collapse.

Xanthorhizasimplicissima. Family Ranunculaceae. The only member of the genus Xanthorhiza, is native to the eastern states of north America. In the wild this shrub grows in sandy soil to a height of approximately 90cm. Its leaves are in a spiral configuration up to 18cm in length with flowers (6 to 20cm) that are produced in star shaped forms of reddish brown to purple. This attractive plant although used for ground cover in gardens, is uncommon in bonsai as its main stem does not produce a large girth. Xanthorhiza is poisonous, its contain the toxin berberine, which can cause nausea, dyspnoea, diarrhoea, nephritis, urinary tract disorders, skin and eye irritation.

Xanthocerassorbifolium. Family Sapindaceae. Native to northern China is a flowering and fruiting species of small tree growing to approximately 8m and can be seen in bonsai collections although uncommon. Its mid-green leaves 12–30cm in length are pinnate with flowers 10–20cm long containing 5 white petals arranged in panicle form, that appear in spring. The fruit a leathery pod splits open in three sections when ripe to reveal the black seeds, which resemble a small horse chestnut seed. Originally the flowers, leaves and fruits were eaten raw with little or no side effects evident. Nonetheless, it would be prudent for those with sensitive digestive systems to cook them before consumption.

YewTaxus Spp. Family Taxaceae. Yews are widely used in landscaping, ornamental horticulture and bonsai in which over 400 cultivars have been created including. The Japanese yew Taxus cuspidata, Pacific yew Taxus brevifolia and Canadian yew Taxus canadensis. All derived from the European yew Taxus baccata considered as Europe’s oldest living tree of which, a specimen can be found in St Cynog’s church yard in Wales dated to approximately 5000 years. The yew majestic and sombre in its appearance has a reputation as a harbinger of bad tidings for example. The yew tree often found in church graveyards as a symbol of sadness was also made into longbows, a weapon used in the battle of Agincourt 1415 by the English in their defeat of the French cavalry.

Yews are relatively slow-growing and can reach heights of 20m (66ft), with a trunk girth averaging 5m. (16ft) The bark is reddish brown with lanceolate, flat dark-green leaves positioned in a frond-like form on the stem. The fruit consists of a bright red cone called an Aril in which a single seed is contained, these are subsequently consumed by birds who disperse them via their digestive system.

All parts of the yew with the exception of the Aril are highly poisonous to humans as they contain the toxin taxane, that can cause the following if ingested. Low blood counts, arthralgias and myalgias, pain in the joints and muscles, peripheral neuropathy – numbness and tingling of the hands and feet. Hair loss, mouth sores, nausea, vomiting, diarrhoea and in some cases the results can be fatal. Moreover, male and monoecious yews in this genus release extremely small cytotoxic pollen, causing headaches, lethargy, aching joints, itching, and skin rashes and asthma.

Zanthoxylum – Kauaense. Family Rutaceae. Is a genus containing approximately 250 species of coniferous and deciduous trees and shrubs, indigenous to temperate and sub-tropical regions. It is known as the ‘prickly ash’ and is a common species in bonsai. The bark has limpet shaped protrusions containing sharp thorns at the centre, its bright green leaves are oval to oblong in shape with 6 to 8 in pairs on a single stem. The fruit are dull red berries tightly arranged in a cluster, that when ripe are used to make the spice Sichuan pepper. According to Asian herbal remedies, the bark was extensively used as a remedy for rheumatism, toothache and colic. Zanthoxylum is not considered poisonous to humans, but it does have the toxin Sesamin, which can cause digestive issues including, nausea, diarrhoea and abdominal pain. Other symptoms may include Anaphylaxis, an extreme case of allergy caused by Sesamin. All edible parts of the tree must be properly prepared prior to ingestion.

ZelkovaSerrata Spp. Family Ulmaceae. Often know as the Japanese or Chinese elm has two varieties, Japan and mainland eastern Asia Zelkova serrata var. serrata, and in Taiwan Zelkova serrata var. Tarokoensis. Z. serrata is a deciduous tree that in the wild can reach a height in excess of 30m (100ft +) and is favoured for its ornamental characteristics. A short fat trunk from which many branches radiate in a typical broom style. (Hokidachi) Its leaves are round to oblong in different shades of green, (Depending on the species) that change through the seasons to yellows, oranges and reds. The flowers in clusters are yellowish-green, which turn brown as they mature. Z. serrata a popular species is regularly found in bonsai collections. Z. serrata has in the past been used for herbal remedies including stabilising the womb during child birth nonetheless, it would be prudent to seek advice before ingesting parts of this species.

The trees and shrubs mentioned in this list are all toxic to some degree for example. In the beginning of the article part I information was given on the Acacia, a native of the African savanna, that have an abundance of thorns for protection. They also use poison in their leaves as a second line of defence against predation, predominantly from browsing wildlife.

Flora once indigenous to specific climate zones are now common place throughout the world in parks, gardens and bonsai, due to their discovery and availability. These species cultivated for their fruit and flowers and other various uses, all have some form of defence. Their toxicity ranges from mild, meaning having little effect on humans and domestic pets, to being potentially fatal.

As to a particular species’ poisonous capabilities we are basically unconcerned, probably due to its benign appearance or attractiveness and addition to a bonsai collection. Nonetheless, this article was written in order to shed some light on floral toxicity and the potential hazards that exist. But it does not mean we should take to wearing protective apparel. Even the most toxic of bonsai specimens, the Yew – Taxus can be handled, providing we refrain from ingesting any part of it and ensuring that any body part in contact, predominantly the hands and the tools we use are thoroughly cleaned.
Until next time BW, N.

 

Toxic Bonsai III

Toxic Bonsai Part III

NandinaNandina domestica. Family Berberidaceae. A common colourful species used in bonsai is not a bamboo plant as it is often referred to, but an evergreen shrub growing to 2m (7ft) tall by 1.5 m (5ft) in width. In springtime new leaves are a bright pink, which turn a glossy green. The flowers are white and in clusters, with fruit in the form of a bright red berry. All parts of this tree are poisonous as it contains compounds that produce hydrogen cyanide, which could be potentially fatal if ingested. Although there are those who claim the tree is non-toxic to humans, ascertaining if there is any truth to the argument is not worth the risk.

NeeaNeea buxifolia. Family Nyctaginaceae. Often referred to as the flowering tropical boxwood, this tree is a native of Puerto Rico. It is a rather twiggy specimen with a large diameter trunk with small long narrow oblong leaves, with new shoots appearing in dark red, flowers and red fruit. No part of this tree should be ingested as it belongs to the Nyctaginaceae family, in which many members such as the Bougainvillaea another favourite in bonsai are poisonous. Symptoms are similar to that of poison ivy and may include, pain, itching or burning skin, blisters and dermatitis.

NutmegMyristica fragrans. Although uncommon in western bonsai collections, can be found in more temperate climes. The problem with Nutmeg seed propagation is that there is no way of knowing once germination has taken place if the plant is male or female. Because this species is dioecious and male trees are unproductive, the common way if one desires a female fruiting tree is to either graft, patch bud or air layer. The Nutmeg although widely use for culinary uses contains the toxin myristicin, a monoamine oxidase inhibitor and psychoactive substance. If ingested in large quantities can induce convulsions, palpitations, nausea, dehydration, and generalized body pain.

OakQuercus. Family Fagaceae. A deciduous and evergreen tree with a variety of species that include, white oak Quercus alba and stone oak Lithocarpus. Oak leaves and acorns are poisonous as they contain tannic acid, which can cause kidney damage, gastroenteritis and diarrhoea in livestock for example. Sheep, goats, horses and cattle, but it has little effect on the domestic pig. It is said humans are not affected providing the tannins have been removed nonetheless, those with sensitive digestion systems should avoid consumption.

OleanderNerium. Family Apocynaceae. A small tree or shrub having approximately 400 different varieties in the genus Nerium can be found in many temperate zones throughout the world. It is widely cultivated as an ornamental plant for parks and gardens reaching heights of 2 to 6.5m. (19ft) Although there now exist many dwarf varieties, which only grow to 26cm (10 ins) and these can be found in some bonsai collections. Oleander when mature has grey bark, with dark green thick leaves arranged in pairs that are relatively narrow in shape. The flowers from white to pink to red are highly scented although much depends on the variety and fruit in a long pod, which when ripe open to reveal large amounts of seed. Oleander although a very attractive plant, is considered extremely poisonous as it contains the toxins oleandrin and oleanrigenin that are referred to as cardiac glycosides. Ingesting any part of an Oleander can cause serious gastrointestinal problems; nausea, vomiting, excess salivation, abdominal pain and diarrhoea. Other reactions to Oleander glycosides include cardiac and central nervous system effects; an irregular or erratic heart rate and drowsiness, muscle tremors, seizures and collapse that can have fatal consequences.

OliveOlea europaea. Family Oleaceae. Olive trees are not toxic and ingesting the fruit has no known side effects. However, olive tree pollen is extremely allergenic and according to the Ogren Plant Allergy Scale, a rating system for plants measuring their potential to cause allergic reactions in humans, it has a rating of 10 out of 10. And as the olive tree is wind-pollinated the pollen if inhaled, can cause headache, blocked sinuses, breathing difficulties and serious asthma attacks.

Orange jasmineMurraya paniculata. Family Rutaceae. A tropical evergreen tree or shrub from Asia is a common specimen for bonsai. It has glossy leaves and white scented fragrant flowers that can remain throughout the growing season and fruit ranging from orange to red, resembling the kumquat. The orange jasmine has no known toxins harmful to humans, but the flowers are highly allergenic and can cause headache, blocked sinuses and breathing difficulties and in some instances severe asthma.

PlumPrunus Spp. Family Rosaceae. Is a diverse group having many species between 19 and 40 according to taxonomists. Arguably the most common plum trees used in bonsai are the European plum Prunus domestica and the Japanese plum Prunus salicina. The flowers are fragrant and vary from white to cream, to various shades of pink. The fruits are usually globose to oval between 2cm to 6cm in size with firm flesh surrounding a hard seed pod. Plum seeds contain the toxin cyanogenic glycosides including amygdalin that decompose into a sugar molecule resulting in the production of Hydrogen cyanide gas, which is extremely poisonous and flammable.

PodocarpusPodocarpus neriifolius. Family Podocarpaceae. There are approximately 97 to 107 species in the genus that are related to conifers and can be found in bonsai collections. Podocarpus are evergreen with cones forming a brightly coloured fleshy, berry-like receptacles inviting birds to feed and in so doing the seeds are dispersed through their digestive tracts. Podocarpus are also related to yews, thus their leaves, stems, bark and pollen are cytoxic. In spring and early summer, the male Podocarpus blooms and releases the cytotoxic pollen and exposure to this can create an effect mimicking the cytotoxic side effects of chemotherapy, where blood cells or bone marrow are most at risk of developing serious infections.

Privet­ – Ligustrum vulgare. Family Oleaceae. A species native to Europe, Australia, Africa and Asia is commonly used in bonsai. Species include the Japanese privet Ligustrum japonicum, Chinese privet Ligustrum quihoui, which are mainly used for ornamental plants and Ligustrum ovalfolium for hedging purposes. The latter if managed regularly is quite decorative, but if left to its own devices will become unruly. Privet leaves and bark have bitter properties, which in China are used for making herbal teas. However, privet species that yield fruit should not be ingested as they are toxic; symptoms include nausea, headache, abdominal pains, vomiting, diarrhoea, low blood pressure and weakness.

QuinceCydonia oblonga Family Rosaceae. Include such species as Chaenomeles japonica and Pseudocydonia sinensis that are small deciduous fruit and flowering trees. The flowers borne in clusters vary according to the species from pale pink to red and both species bear fruit in the form of a pome, which is bright golden-yellow at maturity. Although the fruit is edible, it is astringent and can cause a shrinking or constriction of the body tissues for example, a dry puckering of the mouth due to the tannins present. The quince has been used for both culinary and medicinal purposes but it is poisonous, as the seeds contain nitriles that if ingested will be hydrolysed by the stomach acid producing hydrogen cyanide.

RhododendronSpp. Family Ericaceae. Contains approximately 1,024 species of trees and shrubs both evergreen and deciduous and found throughout the world, from north America, Europe and Asia. They are a common addition to any bonsai collection due to their colourful showy flowers that bloom from late spring to early summer. All rhododenron species including, Rhododendron obtusum, Rhododendron simsii, Rhododendron indicum and Rhododendron luteum are poisonous. They contain Andromedotoxins that are water-soluble diterpenoid compounds in the leaves flowers and nectar. If any part of the plant is ingested symptoms include, salivation, a burning sensation in the mouth, emesis, diarrhoea, muscular weakness, impaired vision and dyspnea. Hypotension and atrioventricular block, a serious cardiovascular effect that may have fatal results.

Rosary PeaAbrus precatorius. Family Fabaceae. Known by other names including the ‘Jequirity bean’ is native to warm and tropical regions and also found in bonsai. Those with children and domestic pets are advised not to keep such a plant due to its very nature. This species with its frond-like leaf formation and bright red fruit is extremely poisonous as it contains the toxin abrin. Abrin is similar in structure to ricin the toxin in Ricinus communis or ‘Castor bean’ plant and some claim that abrin has a higher toxicity level. Abrin is found in all parts of the plant but, it is the seeds that attract the most attention and if crushed, chewed and ingested abrin is released and can be fatal.

RowanSorbus aucuparia. Family Rosaceae. Native to the northern hemisphere are also found in more temperate climes including Africa and Asia. Its growth can be prolific portraying grey bark, compound frond-like leaves and scented flowers white to cream, and orange to red berries. And this combination makes the species very attractive to bonsai collectors. Nonetheless, rowan tree berries are poisonous as they contain parasorbic acid, which is used as a food preservative and in cosmetics. Symptoms can include, eye and respiratory problems, skin irritation and abdominal pain. However, if they are cooked the parasorbic acid is transformed into sorbic acid, which is not poisonous if ingested.

SnowberrySymphoricarpos alba. Family Caprifoliaceae. Also know as the ‘ghost berry’ and ‘wax berry’ a genus of approximately 15 species native to north America are found in other parts of the world. They are members of the honeysuckle family Caprifoliaceae and are used in bonsai for their fragrance and decorative flowers and coloured fruit, white, pink and red depending on the species. The white berries of Symphoricarpos contain the following toxins, viburnin, chelidonine, saponins, tannins, terpenes, tryglycerides and coumarins. If ingested the symptoms are vomiting, blood in urine and delirium. However, the toxic combination has a powerful emetic effect – a gastrointestinal irritant, which causes the victim to expel the berries undigested.

Spindle treeEuonymus europaeus. Family Celastraceae. A native to Europe is a deciduous tree or shrub noted for its colour changes during the season. It has leaves that change from dark green to yellow to red to purple and flowers yellow to green grown in clusters. The fruit, which can be pink, red or purple when ripe open to reveal its orange coloured seeds. This colour change make it a popular specimen for bonsai. But the fruits are poisonous containing a cocktail of toxins including, alkaloids theobromine, caffeine and terpene. Poisoning in children is quite common as the brightly coloured fruits are attractive. Ingesting the fruit can cause liver and kidney damage and can be fatal.

SpurgesEuphorbia Spp. Family Euphorbiaceae. This genus has over 500 species of trees and shrubs including Euphorbia tirucalli, a tall growing shrub native to semi-arid tropical climates. It has a wide distribution throughout Africa and is common in the dry states of north America in particular California. In bonsai E.tirucalli is not one of the most favoured of specimens although it can be found, because of the problems of shaping and pruning. For example, merely cutting a branch or twig causes the plant to ooze a sticky white toxic latex. This latex when in contact with skin is extremely irritating causing redness and a burning sensation. If in contact with the eyes the result is severe pain and temporary blindness. If ingested symptoms are burning to the mouth, lips, and tongue and can be fatal.

TamaracLarix laricina. Family Pinaceae. Known as the black, eastern, red and American larch, is native to north America and Canada and is coniferous and deciduous due to its needle leaf structure that is shed in the autumn. The Tamarac has more medicinal qualities as opposed to toxicity for example. Tea made from the bark was used as a laxative, a remedy for rheumatism and skin ailments. However, this species is prone to attack from the fungal pathogens including Lachnellula willkommii and contact with it should be avoided. It is also argued that oil from the leaves in contact with the skin can cause dermatitis nonetheless, it is a popular species found in many a collection.

TitokiAlectryon excelsus. Family Sapindaceae. Formerly known as the New Zealand oak is as its name suggests native to this antipodean realm. Like its European counterparts it has a twisted trunk with branches radiating in all directions and its apex is formed into a canopy. Its flowers are relatively small and purple in colour and its fruit are a pinky-grey capsule that when ripe, open up to reveal a bright red pulp with a black seed. The Titoki seen in some bonsai collections is poisonous, because it contains tannins and cyanide-producing poisons in its bark, leaves and fruit that if ingested can cause; vomiting, gastroenteritis, diarrhoea, delirium, kidney failure and at worse fatality.

Tea tree (Chinese)Camellia sinensis. Family Theaceae. Camellia sinensis is an evergreen shrub that if left to its own devices can grow in access of 5 metres (16ft) in height. Producing white flowers with bright yellow stamens surrounded by glossy green leaves and fruit having a hard green shell and a single brown seed contained within. There are many cultivars of the tea tree that are used to make a refreshing beverage partaken by countless individuals including, the Camellia sinensis assamica (Assam, India) strain. Nonetheless, the tea tree is considered poisonous because it contains caffeine and tannin toxins that are addictive. It is argued that consuming five cups a day are sufficient to produce addiction and reduced intake or withdrawal can cause; dizziness, headaches, palpitations, indigestion, constipation and insomnia. Moreover, excessive intake or over indulgence can be harmful to pregnant women.

In toxic bonsai part IV we will conclude the alphabet on toxic bonsai, until then BW, N.

Toxic Bonsai II

Toxic Bonsai Part II

Ginkgo biloba – Family Ginkgoaceae. Also known as the maidenhair tree native to China is the only living species in the division Ginkgophyta, as all others are now extinct. Its fruit is used for culinary purposes and in traditional Chinese medicine and is considered by some to contain aphrodisiac properties. However, the seed pulp has toxins that are not destroyed when cooked and if eaten in large amounts poisoning by methyl pyridoxine, (neurotoxin) can cause epileptic seizures. In addition, the sarcotesta or fleshy seed coat is poisonous and disposable gloves are required as they are able to cause dermatitis and or blisters. Other side effects include; nausea, vomiting and diarrhoea.

Guelder roseViburnum opulus. A deciduous shrub can be found in woods, hedges and in areas containing a lime-rich soil compound. The tree has large white flowers with smaller yellow ones on the inner part of the cluster, the white flowers are infertile whilst the yellow ones are fertile. In autumn the flowers produces red berries with a single seed in each. All parts of the tree are poisonous to humans as they carry toxins such as iridoid glycoside, isobutyric Acid, coumarins, tannins and saponins. These can cause severe nausea, vomiting, diarrhoea, swelling and over heating.

Grevillea robusta – Family Proteaceae. Commonly known as the Australian silver oak although uncommon can be found in European bonsai collections. This evergreen tree with its feather like leaves similar to a fern frond is known for its prolific growth and produces golden orange blooms. The flowers and fruit of G. robusta are poisonous, they contain hydrogen cyanide sometimes referred to as Prussic acid and tridecylresorcinol responsible for severe contact dermatitis.

Honey LocustGleditsia triacanthos. Is not a toxic tree unlike its ‘look-alike’ counterpart the black locust, Robina pseudo which is extremely poisonous. The two species can be identified as follows: the black locust has wisteria like flowers and small black seed pods, whilst the honey locust has small clusters of flowers and long seed pods 15–20 cm. Honey locust trees have extremely sharp thorns 3 cm to over 20 cm protruding from the branches, that harden and turn red as they age, then fade to grey becoming brittle as they mature. As a result the honey locust is considered difficult to wire and shape although thorn less varieties (Gleditsia triacanthos var. inermis) are occasionally found growing wild and are available as nursery plants. But there is no guarantee they are free from toxins.

HollyIlex. Family Aquifoliaceae. There are 400 to 600 species ranging from evergreen to deciduous trees and shrubs, found in temperate to tropical climates around the world with many shaped into bonsai. The bark is relatively smooth with small nodules known as ‘warts’, the glossy oval leaves are dark green in colour. Holly is dioecious meaning that the flowers of male and female are peculiar to their own sex and tree. These flowers 4 white petals when mature become scarlet berries and are attractive to birds, whom ingest them, but pass the seed through their digestive system intact. However, for humans they are predominantly poisonous as is the rest of the tree. Holly contains such toxins as caffeic, feruloylquinic, chlorogenic and quinic acids, kaempferol, tannins, rutin and theobromine compounds found in all parts of the plant. Holly berries can cause severe vomiting, diarrhoea and nausea that can be fatal for young children if consumed.

HawthornCrataegus. Family Rosaceae. Is a species quite common in bonsai grown for its floral display. The flowers are hermaphrodite, meaning both male and female reproductive parts are contained within each flower. Flowers are highly scented, white or occasionally pink with five petals, and grow in flat-topped clusters, with small pome fruits and thorny branches. Although hawthorn fruit is not toxic if used in herbal remedies and culinary purposes it must be prepared properly. Failure to do so can cause nausea and sedation, cardiac arrhythmia and dangerously low blood pressure if taken in large quantities. Those taking digoxin a medication used to treat various heart problems should avoid hawthorn completely.

Indian PeaLathyrus sativus. Family Fabaceae. Although not really considered as bonsai material, is often cultivated for its striking blue flowers, but more importantly as an insurance against famine in third world countries where drought is a major problem. The crop is harmless to humans if ingested in small quantities occasionally, but continuous intake over a prolonged period (3 months) can have serious side effects. The plant produces seeds containing diaminopropionic and neurotixic amino acids and can cause a disorder known as lathyrism. A neurodegenerative disorder causing paralysis of the lower body, emaciation of gluteal muscle and brain damage in children.

Idesia – Family Salicaceae. A tree not normally found in western bonsai collections is common in its native regions of China, Japan, Korea and Taiwan. It is a deciduous tree with greyish-green bark and heart shaped dark green leaves 8 to 20cm in length protruding from a red petiole. Flowers are small, fragrant and yellowish green in colour. The fruit of the Idesia is a small orange berry, which ripens to dark red almost purple in colour, that can be consumed, but as with all wild fruit care should taken in its preparation prior to ingestion. Idesia has no known toxins that are harmful to humans.

Incensed Cedar – Libocedrus decurrens. Family Cupressaceae. Is a popular species for bonsai as formal, informal and literati styles. It contains strong volatile oils including thujone, a ketone that is known to be toxic in large quantities and it is best known as a chemical compound in the spirit absinthe. Thujone has a menthol odour and is considered toxic to the brain, kidney, and liver cells and could cause convulsions if used in too high a dose. It should not be used during pregnancy, breastfeeding or those with kidney weakness.

JacarandaJacaranda mimosifolia, Family Bignoniaceae. Has been cultivated in many temperate parts of the world and also in bonsai thriving in sandy soils with full sunlight. Young trees are unable to withstand cold conditions, but mature specimens are able to tolerate temperatures down to -7°C (19°F) for brief spells. The jacaranda is known for its stunning display of flowers produced in large panicles, with colours ranging from blue to purple and fruit in a flattened oblong pod containing the seeds. Nonetheless, the Jacaranda is said to be toxic, exposure to the pollen can cause skin irritation and rash. Ingesting either and or flowers and seeds can result in, vomiting, nausea and abdominal pain.

Jade treeCrassula ovata. Family Crassulaceae. Has other common names including, ‘Friendship tree’, ‘Money tree’ and ‘Lucky plant’ and is native to south Africa and Mozambique and is found throughout the world as a common house plant. Arguably, C. ovata is not a true tree in the sense of the word, meaning it does not shed its leaves or needles on an annual basis as deciduous and conifers do. It is a succulent, a water retaining plant that has the ability to thrive on limited water sources. Whereas most conifers and deciduous trees require a constant supply of water that is continuously pumped through its system. In addition, its trunk and branches never become true lignified tissue, they remain soft and fleshy during the plants life. Nonetheless, it is found in many bonsai collections with some attractive results. C. Ovata has rich jade green thick, shiny, smooth, leaves growing in opposite pairs along the branches. Some varieties may have a yellowish-green appearance, whilst others have a red tinge on the edges. The flowers of C. Ovata under the right conditions are small star-like white or pink flowers arriving in early spring. The jade plant is poisonous to domestic pets (dogs and cats) and marginally toxic to humans and if ingested may cause vomiting, diarrhoea, abdominal discomfort, loss of appetite and lethargy.

JasmineGelsemium sempervirens. Family Gelsemiaceae. A relatively common species found in bonsai collections for its individual trumpet shaped yellow flowers, that are strongly scented and appear on the tree prior to the production of new growth. However, all parts of this species are poisonous containing toxins such as strychnine related alkaloids and gelsemine a highly toxic compound that acts as a paralytic and often results in death. In addition, the sap from this plant can cause severe problems if in contact with those having sensitive skin causing rash and swelling.

JuniperSpp. Family Cupressaceae. This order has many species widely used in bonsai horticulture and it is argued that they are all toxic due to the volatile oils found within the plant. Alpha-pinene, myrcene and sabinene, which if ingested can cause diarrhoea, nausea and hypertension. Although considered by many to be safe for culinary uses, juniper berries if consumed on a regular basis can cause cause serious kidney damage. Pregnant or breastfeeding women are advised to refrain from usage due to the risk of miscarriage. Those taking Telmisartan a prescribe drug, which is used to treat high blood pressure (hypertension) should refrain from ingesting any part of this plant.

Kentucky coffeeGymnocladus dioicus. Family Fabaceae. A species native to north America is also used in bonsai. Its rough ash-grey bark similar to that of oak can fall or peel away from its surface leaving scarring and indentations, which adds character to the tree. Its flowers are dioecious and has fruit in the form of a hard-shelled bean in pods from 13cm to 25cm. (5 to 10 inches) The seeds are considered poisonous as they contain the toxic alkaloid cytosine, that if consumed can cause respiratory difficulties, which can have fatal results. However, it is argued that if the seeds are roasted, the cytosine is neutralized, but for those with respiration problems it is not a risk worth taking.

KumquatFortunella japonica. Family Rutaceae. The species has no known toxins harmful to humans and is usually grown as an ornamental plant, but is found in bonsai collections. The fruit resembles a small orange a little larger than a grape, its peel has a sweet flavour whilst the inner pulp is sour but is edible when cooked. It is also ingested in its raw state, but those with a sensitive digestion system should refrain from doing so due to the concentration of oils (Limonene) and acids within the fruit. Which can cause diarrhoea, nausea and other abdominal complaints.

KurrajongBrachychiton populneus. Family Malvaceae. Is native to Australia and found in various habitats from wet coastal districts to semi-arid regions. The bell-shaped flowers range in colour from pale cream to pink with simple pointed shaped leaves. The seeds are covered in small stiff irritating hairs, which have to be removed prior to roasting and ingesting as they contain toxins. Although these are not considered dangerous to humans they can be to domestic pets, sheep and cattle causing lameness, tremors, collapse and in some cases fatality depending on the victims disposition.

Laburnum – Family Fabaceae. Is a genus of two species of trees that are Laburnum anagyroides known as the common laburnum and Laburnum alpinum the alpine laburnum. They are often found in bonsai collections due to their colourful yellow pea-like flowers. That are in pendulous leafless racemes 10–40 cm (4–15.5 in) similar to the wisteria, making them very popular trees. However, all parts of the tree are poisonous; roots, bark, wood, leaves, flower-buds, petals and seeds as they contain the toxin cytosine a nicotinic receptor agonist that produces a biological response. Symptoms may include intense lethargy, vomiting, convulsion, coma and severe diarrhoea.

Laurel (Cherry) Prunus laurocerasus. Family Rosaceae. Is a shrub often used for topiary in hedging and also in bonsai as it is easily shaped. The leaves are a shiny dark green with creamy white flowers and fruit that turn black when ripe. The whole plant is poisonous containing the toxin hydrogen cyanide, also known as prussic acid and identifiable by its strong almond-like smell and bitter taste. Symptoms can include breathlessness, weakness, spasms, convulsions, coma and respiratory failure.

ManchineelHippomane mancinella. Family Euphorbiaceae. Classed as an endangered species is a flowering and fruiting tree native to Florida, Mexico and the Bahamas growing among mangroves and in coastal waters. Its fruits are green and round resembling a small apple, hence its common name the ‘Beach apple’. H. mancinella is an evergreen tree with reddish-grey bark, glossy oval green leaves, greenish-yellow flowers and grows to a height of approximately 15m. (49ft) It is also known in Spanish as ‘Manzanilla de la muerte‘, the ‘Apple of death’ and is considered one of the most dangerous trees in the world. All parts of the tree are extremely poisonous with arguably the sap being the most toxic as it contains phorbol a member of the tiglian family of diterpenes. Even the smallest amount diluted in water can cause severe blistering of the skin and ingesting the fruit can cause intense gastrointestinal problems that can have fatal results. Manchineel is cultivated for its timber source, but little is known of its use in bonsai.

MistletoeViscum album. A hemiparasitic plant in the order Santalales. A mistletoe seed attaches itself to a tree by a structure called the haustorium and is able to germinate independently, but as it develops it penetrates the branch of its host absorbing nutrients and water. The European mistletoe has evergreen leaves in pairs with waxy white berries in clusters of two to six, that contain the toxins polysaccharides, alkaloids, and lectins. Which can cause blurred vision, nausea, abdominal pain, diarrhoea, blood pressure changes that can be fatal. Those taking Telmisartan a prescribe drug, which is used to treat high blood pressure (hypertension) should be aware of potential problems. Mistletoe is found in bonsai, but is uncommon as it can affect other species within a collection.

Mock orangePhiladelphus coronarius. Family Hydrangaceae. A species of flowering plant native to Southern Europe is a deciduous shrub growing to approximately 3 m tall by 2.5 m wide and often found in bonsai collections. What makes this a popular collectable species is because of its bowl-shaped double white flowers on prominent stamens, that are highly fragrant. The ‘toothed’ dark green leaves turn to yellow in autumn adding more colour to the plant. Yet the seeds and flowers carry toxins that although considered mild and not life threatening, can cause nausea, vomiting, diarrhoea and skin rash if consumed. But much will depend on an individual’s digestive system.

MyrtleMyrtus communis. Family Rosopsida. A common species found in bonsai has reddish brown bark that is apt to peel off in mature plants. The flowers usually white in colour have five petals and numerous long stamina and can be heavily scented. The leaves are small, narrow and dark-green and filled with oil, which is visible as small dots when held against a light. This oil is slightly toxic and may cause headaches, nausea, indigestion, and may colour urine purple if consumed in large quantities.

In toxic bonsai part III we continue the discussion on species ‘N’ to ‘T’ until then BW, N.

Toxic Bonsai I

Toxic Bonsai (Part I)

In the early days of bonsai horticulture tree varieties included the Juniper JuniperusSpruce Picea Pine Pinus and Larch Larix. As time progressed, more species were added for example, flower and fruiting varieties Wisteria Floribunda and Azalea genus Rhododendron, in the genus Prunus plum, cherry, peach and apricot. Today many other species from around the globe have now become part of bonsai horticulture including those which may be considered as common, the European Horse Chestnut Aesculus hippocastanum the unusual Acacia genus Acacia and the exotic, the Madagascar Euphorbia milii described below.

Many bonsai enthusiasts either have traditional collections predominantly coniferous, whilst others prefer deciduous and some will have an assortment of species. These artistically shaped miniature trees portray delicate, graceful and rugged forms and although their beauty is beholding, all is not what it seems. These little adaptations are able to produce toxins just as their full-sized counter parts can, which have the power to incapacitate all fauna including humans even to the point of being lethal.

All flora have developed ways to defend themselves, from the production of toxins in their leaves, fruit and seeds to the emittance of gas and or extremely sharp thorns which deter most from ravaging their foliage. The European Horse Chestnut Aesculus hippocastanum a large deciduous tree has greenish-yellow to white flowers and fruit contained in spiny capsules. In the UK at autumn time children collect the fruit capsules and remove the seeds from within, thread them on lengths of string and participate in an old traditional game of ‘Conkers’. A game dating back to 1848 where turns are taken in striking each others ‘conker’ until one breaks; yet the players who take part in this ritual, are probably unaware that these ‘conkers’ or seeds are poisonous.

common-horse-chestnut

Acacia genus Acacia, of which there are approximately 160 species of trees and shrubs within the pea family Fabaceae are native to Africa and Australia. Those of the African savanna have an abundance of thorns for protection, but also use poison in their leaves as a second line of defence. When the tree is disturbed it pumps poison into its leaves releasing ethylene gas from the pores. This gas release if detected by other acacias in near proximity sound the alarm alerting them to a potential threat and in so doing they too inject poison into their leaves.

the-acacia

The Madagascar Euphorbia milii commonly known as the Crown-of-thorns – a shrub with flower clusters and red, petal-like bracts has thorns that are poisonous. These thorns if damaged secrete a latex sap called urushiol and when in contact either on or under the skin can cause a sumac rash a very serious allergic reaction; a form of dermatitis.

the-madagasacar

Perhaps the question on most peoples lips is why would you want to have a tree that is poisonous? The question can be answered in two ways (a) why do people keep exotic pets, arachnids such as the Mouse Spider Missulena, which is every bit as dangerous as it looks or a Burmese python Python bivittatus that can be extremely aggressive. Pterois, or lion fish with its showy pectoral fins and venomous spiky fin rays, a popular choice among marine aquarists. It is really down to human nature, some are content to have the mundane household ‘moggy’ (cat) as a pet, whilst others want something which can be seen as diverse. (b) It is possible that somebody was given a bonsai as a gift without the purchaser bothering to research the tree’s attributes, it just looked nice. Furthermore, most bonsai contain toxins of one sort or another in their defence that vary in type and amount.

There are countless species of flora that exist on the planet including wild or natural varieties and hybrids, the latter pioneered by Gregor Mendel whom is credited with starting the hybrid plant revolution with his genetic studies of peas in the early 1900s. And least we forget those that have been genetically modified to produce more flower and fruit and combat insect infestation. To describe the peculiarities and properties of flora is a monumental task and narrowing it down specifically to bonsai, would amount to a PhD thesis. Therefore, the discussion will be further refined focussing on bonsai that can be found in most collections either common or unusual. The complete topic will be in four parts this post being part I and arguably the most efficient way in undertaking this, is to list them in alphabetical order.

Acer – Family: Aceraceae. The toxins are found within the leaves which increase as they wilt and die. It is also found in the seeds although the content is less. The acer although not harmful to domestic pets and humans is potentially fatal to equines if ingested as the poison damages red blood cells, diminishing their ability to carry oxygen. Death can occur from between 18 hours to 10 days.

AppleMalus Spp. The seeds are mildly poisonous and contain a small amount of amygdalin a cyanogenic glycoside that play important roles in many plants including apple varieties. However, the amount of cyanogenic glycoside contained within the seed is not considered dangerous to humans nonetheless, ingesting a large quantity can provide severe side effects.

Alder BuckthornRhamnus frangula L. This tree or shrub found among hedgerows, along roadsides and in woodlands, has a number of toxic chemicals, including emodin that are within its bark and purple-black berries or fruits. Emodin is a purgative resin, which is also found in rhubarb and also produced by many species of fungi. If ingested the symptoms are: collapse, convulsions, diarrhoea, gastroenteritis, haemorrhage and vomiting.

Azalea – genus Rhododendron Family Ericaceae. Is a common species that appear in bonsai collections but, it is poisonous. The toxins Grayanotoxin and arbutin glucoside are found in all parts of the plant the flowers, leaves and nectar – the latter often referred to as ‘mad honey’. They can cause nausea, vomiting, weakness, dizziness, breathing difficulties, low blood pressure, reduced heart rate and irregular rhythm, which could be life threatening.

Beech – genus Fagaceae. Indigenous to Europe, Asia, and North America produce a triangular shaped fruit called beechnuts in the autumn. These nuts often used as a food source are high in tannins having a strong bitter taste and are toxic to both canines and humans especially children if consumed in large quantities. The European beech Fagus sylvatica, is believed to be more toxic than its the American relative, Fagus grandifolia. Symptoms include; vomiting, diarrhoea, abdominal pain, nausea, fatigue and dilated pupils – mydriasis.

BirchBetula Spp. Has more homeopathic properties as opposed to toxins nevertheless, pollen from the silver birch, Betula pendula, is the second most severe allergen for people as it can travel many kilometres via the wind. It is able to cause hay fever, conjunctivitis and severe respiratory problems with disease to the lungs and asthma. Severe cases of pollen infection do require medical attention.

BoxBuxus sempervirens. A common species found in bonsai collections is one to handle with caution as it is poisonous to humans. The leaves produce an alkaloid buxine which causes nausea, vomiting and diarrhoea and respiratory paralysis in humans and livestock. Contact with skin can cause irritable rashes and when pruning the clippings should be handled with care.

Cherry (Wild) – Prunus Spp. Wild Cherry trees produce fruit that are reddish black in the summer, which can be consumed. However, the wild cherry twigs and leaves contain the chemical prunasin, a cyanide that when ingested, can be fatal. Prunasin breakdown and cyanide release occurs when the tree becomes stressed and an indication of this is when the leaves begin to wilt.

Chestnut (European horse) – Aesculus hippocastanum. As described above.

CotoneasterCotoneaster Spp. Are grown as bonsai mainly for their display of coloured berries ranging from bright orange to red to purple. This species is said to be a high risk in the toxicity range, because their leaves, berries and flowers all contain cyanogenic glycosides. These toxins if ingested are converted to cyanide during digestion causing serious effect on the heart, liver, kidney and brain. For children the risk is higher than in adults, although much depends on the amount consumed.

CitrusCitrus Spp. Citrus oil is a concentrate of the fruit produced by the tree and also a protective barrier found on the leaves, which can be activated by a gentle rubbing with the fingers. The scent of the oil is pleasant but the taste is bitter, leaving a nasty after taste due to Coumarin a fragrant organic chemical compound in the benzopyrone class. Although citrus oil is not harmful to humans, felines are more susceptible to citrus poisoning, which can result in diarrhoea, vomiting, liver damage or even death.

Douglas FirPseudotsuga menziesii. A native of north America has smooth grey bark when young that are covered with numerous resin blisters, which should not be ingested. The leaves needle like in appearance have two whitish stomatal bands on their underside, that are pores to allow the exchange of gas. If the leaves are damaged they emit a sweet fruity-resinous scent. Ingesting needles can result in vomiting, anorexia, abdominal pain, and lethargy. Other trees with similar attributes are: the Balsam Fir Abies balsamea, Blue Spruce Picea pungens, Red Spruce Picea rubens, White Spruce Picea glauca, Scots Pine Pinus sylvestris and Red Pine Pinus resinosa.    

DogwoodCornus Spp. A genus comprising of approximately 60 different varieties known for their brilliant floral displays in spring time. The fruits of many dogwood varieties are rather tart and unpalatable due to the amount of Tannins, but can be consumed if cooked. However, fruit of the dogwood in the sub-genus Swida are toxic and should be avoided. Dogwoods are prone to attack by insects and fungal disease for example. Botryosphaeria Canker a dark yellowish pitch that oozes from dogwoods and Phytophthora a reddish orange sap oozing from the tree as a result of destroyed tissue. Dogwoods infected with this disease should be kept away from pets, children and other plants.

Dieffenbachia – Family Araceae. A native from Mexico, West Indies and Argentina is widely cultivated as an ornamental houseplant and although not considered by some traditionalists as bonsai material, it is found in some collections. Dieffenbachia is poisonous, it contains Raphides needle-shaped crystals of calcium oxalate crystals and if the leaf or its residue is ingested it causes a burning sensation and erythema a redness of the skin or mucous membranes, caused by increased blood flow. Dieffenbachia can cause other symptoms including numbness, oral irritation and localized swelling.

ElderSambucus racemosa. Elder is cited as a poisonous plant because the bark contains calcium oxalate crystals and the leaves and unripe fruits and seeds cyanoglycoside sambunigrin. But, ripened fruit when subjected to a cooking process reduces the toxins. Elder suffers from Hyphodontia sambuci or Elder Whitewash a basidiomycete fungal pathogen forming a thin white, pruinose (flour-like dusting) on the limbs and branches. The pathogen should be avoided as the spores are easily carried by a gentle breeze.

ElmUlmus. The elm has no toxins to speak of that are a danger to humans or domestic pets but its seeds, leaves and bark should not be ingested as a precaution. Because it is possible that the tree may be infected by Ascomycetes a pathogen relatively common to this species. Ascomycetes not only infest and destroy, they also produce secondary metabolites that are poisonous.

Eucalyptus – Family Myrtaceae. The leaves of this tree contain an oil that if treated and diluted can be safe for adult humans. But untreated oil is extremely toxic and ingesting a small amount (3.5 mL) can have fatal results. Symptoms of eucalyptus poisoning may include stomach pain, a burning sensation, dizziness, muscle weakness, small eye pupils, suffocation, nausea, vomiting, and diarrhoea.

Ficus – Family Moraceae. Is a genus of approximately 850 species that include trees, shrubs and vines collectively known as fig trees. Common species used in bonsai Ficus microcarpa and Ficus benjamina are quite popular especially as a beginners tree. However, they are poisonous due to the milky white sap containing Furocoumarins psoralens and ficin that oozes out when pruned. This sap causes Dermatitis and allergic reactions for example, itching of eyes, coughing and wheezing, skin irritation with redness and stinging.

Forsythia – Family Oleaceae (olive family) is also a popular choice in bonsai and there are eleven species predominately native to Asia. The species Forsythia suspensa is considered a major herb used in Chinese medicinal practices as it is non-toxic. But for safety reasons, one should not consume any part of the plant that is not edible.

Firethorn Family Rosaceae. A large shrub with sharp thorns related to the Cotoneaster (Cotoneaster is thornless). This a popular choice for bonsai due to its bright red and orange fruit that are toxic. The seeds of the berries contain cyanogenic glycosides as do almonds, apples, cherries and plums that can cause gastro-intestinal problems when ingested raw. They are only edible if crushed and washed under running water.

In toxic bonsai part II we continue the discussion on species ‘G’ to ‘M’ until then BW, N.

The Stratification of seeds

In nature trees have particular ways of dispersing their seeds for example, by the wind and by animals and birds that consume and dispense them through their digestive system. A walk through a city park or tree-lined avenue will produce a variety of seeds depending on the species of tree in situ. Such seeds released from the parent plant are in what is termed as a dormancy stage, that can be associated with the following: climatic conditions, immaturity, light, genetic variation and protection from predation.

scots-pine-seeds

It can be agreed that all tree seeds are dormant, some are considered to have ‘deep’ dormancy attributes requiring long periods of pre-treatment for example, the Ash Fraxinus excelsior 8 to 16 weeks warm at 15°C plus and 16 to 32 weeks cold at 4°C. Whilst Birch (Silver) Betula pendula is considered to have ‘shallow’ dormancy with a treatment of only 3 to 9 weeks of cold at 4°C.

Dormancy is a natural state of being in many plants, its function is to ensure that the seed will germinate at an appropriate time. However, seeds can remain in a dormant state and fail to germinate although conditions, temperature, water and light are in adequate supply. Why this phenomena occurs can be attributed to a seed’s morphological and physiological requirements, because seed dormancy is able to originate in different parts of the seed, for example, within the embryo or its coating – the shell or husk. Thus, dormancy can be deemed not as a constant, but as a variable because it is a common phenomenon encountered in a large variety of trees. To break dormancy and initiate germination, the process of stratification is needed and this method requires different techniques of which, there are various approaches depending on a particular species of seed.

Seeds having two dormancy combinations, a seed coat dormancy and an internal dormancy (Embryo) require the seed coat or shell to be treated first either by soaking in water and/or scarification. The internal dormancy is then subjected to the following treatment. Warm temperatures to initiate root growth then cold in order to break bud dormancy, then warm to encourage the shoot to sprout and complete the germination process.

There are various methods of scarification and stratification – too many to list them all in this discussion, but the most common approaches are mentioned.

Cold stratification – is when a seed/s spends time in or on the ground from the autumn to the spring and during this time it is subjected to the elements, which soften the hard shell, husk or casing allowing the cold to penetrate within. This cold triggers the seed’s embryo to germinate and eventually the seed sprouts pushing its way through its casing searching for light and nutrients. This cold stratification process occurs naturally in the wild, but it can be mimicked in a home environment and the following methods explain how.

Seeds collected in the autumn can be placed in containers with a growing medium for example, a mixture of soil and sand, soil and vermiculite, moss or other potting compost. The growing medium must be damp not wet, because wet soil is apt to cause mould and fungal disease, that can attack the seeds. In most cases the seeds are positioned on top of the growing medium and lightly covered with a sprinkling of the same composition. Then placed in a plastic bag and sealed then stored in the bottom of the refrigerator for 4 months. The temperature must be between 1°C and 5°C (34°F and 41°F) to ensure the stratification process is achieved. After the stratification period has concluded, the containers can be placed in a warmer environment to assist in growth development. However, some species require longer periods of stratification for example 5 to 8 months, whilst others only need shorter times and the easiest way to monitor a seed’s progress, is to check them periodically.

Seeds can also be soaked in water for 6 to12 hours then given the cold stratification process. It is said that this method reduces the amount of time needed for stratification, because the seeds will have absorbed sufficient moisture, which allows the chemical changes to take place. However, the time period for soaking seeds depends on the species and also the hardness and thickness of the husk, shell or coating; excessive water use can cause the seed to rot.

Warm stratification – some seeds including the pomegranate Punica granatum and the lemon genus Citrus, a popular choice among bonsai enthusiasts can be stratified in a warm environment and the sowing process is the same as described above. The container is then sealed in a bag or propagator and placed in a warm environment, temperature between 18-24°C. (65-75°F) The lemon does not require scarification nor removal of any residue, it can be planted immediately once removed from the fruit. However, pomegranate seeds do require the flesh to be removed to avoid pathogens and fungal attack.
Pomegranate seeds if not needed immediately can be placed on a piece of kitchen towel and left to dry. I have pomegranate seeds that are 3 years old, these are stored in an air-tight plastic bag, a few were sown in a small container on a bed of soft paper and covered with tepid water. They have now germinated after 3 weeks and will soon be ready to plant in different soil mediums to determine, which is more advantageous to their growth and well being.

pomegranate-seedlings

3yr-pomegrante-seeds

Warm and Cold stratification – when a seed requires both warm and cold stratification, the warm process comes first followed by the cold process. The warm stratification is required to soften the seeds outer shell or husk, this allows the seed embryo to mature. Warm and cold stratification is relatively easy to achieve, a seed planted in late summer will be warmed by air temperatures, and moistened by watering. The temperatures will gradually reduce as autumn changes to winter, but will rise again in the spring. Seeds using the warm and cold method of stratification need only one treatment then they are ready to germinate, further treatment can result in the seed’s demise.

Hot Water Treatment – seeds with hard shell coats such as peach and plum genus Prunus, hazel ‎Corylus avellana and the brazil Bertholletia require what may be deemed as a more drastic approach prior to stratification. Because their hard shells do not permit water to enter and water prevention stops the seed from beginning its germination. One method of overcoming this problem is by soaking the seeds in boiling water then allowing them to cool down for a day – this is one method of scarification.

peach-plum-and-hazel-seeds

Seeds that have been successfully scarified using the hot water treatment will either swell in size or simply sink to the bottom of the container for example. The black locust Robinia pseudoacacia a flowering deciduous species will swell, whereas Acer palmatum will sink. Seeds not responding to this treatment can be subjected to the process again however, not all will be successful, some may take several years to germinate and some may never do so.

Scarification: preparing seeds for stratification – there are differences of opinion regarding the preparation of seeds, some will argue that all unwanted material such as, pods and remaining fruit pulp be removed leaving a clean seed. In addition, seeds contained in hard shells for example, Prunus varieties, common horse chestnut Aesculus hippocastanum and oak Quercus, should not be removed from their coatings. Because the seed is vulnerable to harm from pathogens and fungi.

Nonetheless, some hard-coated seeds do require some scarification, their hard casings need to be scraped or cut by using a sharp pointed knife. They can also be soaked using the hot water process, both methods permit moisture to enter the casing allowing stratification to take place. But care and attention must be given when using a blade, hot water and indeed such methods using chemicals (sulphuric acid and household bleach) and fire.

Others contend that removing a seed’s hard case or shell prior to stratification, speeds up the germination process providing it is planted in a sterile soil composite. Alternatively just put the seed in a container with a growing medium and let nature do the rest. But allowing nature takes its course does not always produce the desired results for example. A variety of prunus seeds were scarified and planted in the autumn of 2015, thus far there has been no sign of germination. The problem could be due to morphological and physiological attributes or simply that the seeds are sterile nonetheless, perseverance is the watchword, hence they will be stratified again via the cold treatment.

Sowing seeds – seeds are a relatively cheap way to produce new trees and many varieties can be spring sown after cold storage. Others must be freshly sown in the autumn whilst they are still soft and fresh, because they require stratification and nature is arguably the best horticulturist in this respect. However, seeds acquired in the spring cannot be planted in autumn, because they will have lost their freshness and will have dried out. Nonetheless, the above described methods of stratification should help solve the problem.

All tree seeds regardless of their species do require good growing mediums, but there are exceptions to the rule for example. In Finnish quarries wind-blown seeds of the Scots pine Pinus sylvestris can be seen growing quite happily in sand – a growing medium of poor quality with little nutrients, yet they survive quite well. Alternatively a fruit bearing tree requires soil that is deep and fertile and free from high water retention. Good air circulation in the soil sustains health and promotes sturdy growth, it also discourages Botrytis cinerea, a common disease, causing a growth of fuzzy grey mould. Pythium a genus of parasitic oomycotes classed as fungi that can be transferred from the feet of the Sciarid fly or Dark-winged fungus gnat mentioned in the previous article Pest And Diseases.

 

botrytis-disease

It can be argued that seeds are delicate in their form, but in actual fact they are robust and quite hardy able to withstand high and low temperatures and can be stored in the right conditions for long periods of time. What is/are more appropriate to the delicacy issue is/are the seedlings that require care and attention until they mature.

If there are any questions relating to this article or any others posted on this site, please feel free to post them. The next post in about 2 weeks is a topic not often discussed but one of concern ‘Toxic bonsai’. Until next time BW, N.

Pests and Diseases

PESTS AND DISEASES

This post is probably not the most exciting of topics to discuss, but we should be mindful of the pests and diseases affecting bonsai especially those, which cannot tolerate cold conditions and are kept inside. All flora are susceptible to attack from pests and diseases whether grown naturally or cultivated. In an attempt to eradicate these unwanted problems most fruiting and flowering specimens are sprayed with a fungicide or repellant. Chemical protection does in many respects produce the results intended, but some will argue that it also destroys those creatures that eradicate the unwanted. Moreover, it can be said that when winter arrives many pests will die due to loss of foliage and the coming cold.

Nonetheless, there are such pests whom are able to survive via hibernation hidden beneath a tree’s bark or in it’s seed pods. For example, the Oak – genus Quercus, a favourite of the Tortricid Moth caterpillar – Family Tortricidae that destroys acorns. Carpenter Ants – Genus Camponotus hibernates under pine tree bark. The spruce beetle, Dendroctonus rufipennis its larvae bores into the phloem of conifers and feeds on the live tissue. And the Asian longhorn beetle Anoplophora glabripennis a native of China and the Korean peninsula excavates 1cm diameter holes in the main trunk causing sap bleeding. Eventually the affected tree dies.

Diseases include; ‘Red band needle blight’ Dothistroma, needle blight affects conifers most commonly pines. It causes needle loss, which eventually kills the tree. Ash die-back Fraxinus excelsior affects ash trees it is caused by the fungus Hymenoscyphus fraxineus, that blocks the tree’s water transport system causing leaf loss and ultimately die-back of the tree’s apex or crown. Horse chestnut canker a bacterium species known as Pseudomonas syringae pv. Aesculi. It causes extensive bleeding areas on tree stems. Phytophthora austrocedri affects junipers causing die-back of foliage, stem and collar lesions and eventually death.

The above mentioned pests and diseases are but a few of the many that exist around the world, attacking many species of tree both deciduous and coniferous. Arguably such devastation is due to climate change and infestation via unwanted importation of packaging material. For example wooden boxes and crates and although authorities do much to enforce regulations, it is difficult to halt the invasion.

With bonsai that must be kept away from cold conditions either pre- (trees in training) or established, they too are susceptible to pests and disease. We like to assume that our indoor environment is free from miniature beast invasion – nothing could be further from the truth. The ‘greenhouse’ or home is riddled with the little monsters and no matter how vigilant we are, eradication is virtually impossible. Arguably, the cause why these mini beasts are able to thrive successfully is due to the temperate conditions abundance of food and water.

In the article ‘New material for bonsai part I’ a paragraph discussing the Red Spider Mite was given including an image depicting its appearance. As stated, evidence of these microscopic arachnids existence was revealed due to their very fine webs, which allow them to roam at will. Getting rid of these unwanted pests is in itself a difficult task. But can be achieved using horticultural sprays and soaps. Other common pests causing disease are described as follows.

Mealybugs – quite visible to the naked eye are related to scale insects and congregate on leaf joints and the undersides of leaves. They damage plants by sap sucking, which causes the leaves to wilt, turn yellow to brown and eventually fall from the plant.Removal of this pest(s) can be achieved either by spraying them with water or via a chemical spray designed for Aphid treatment. The plant then should be isolated from others until the treatment is successful and the plant has recovered.

 

mealybug

Aphids – normally a pale green in colour can be found in other shades such as grey and black. Having arrived on a plant their numbers rapidly increase infesting the plant in great hordes with a preference for the underside of leaves. As with the Mealy bug they also suck the sap from the leaves and if not removed quickly, the plant may become infected by disease and viruses. Aphids can be removed relatively easily by the use of warm soapy water directly sprayed on them. Alternatively a chemical application designed for this pest can be used, but the plant should be isolated until the treatment is completed and the plant is free from infection.

 

aphid

Scale Insect – there are more than 25 species of these limpet-like creatures, which makes identification difficult due to their well camouflaged appearance. They devastate a wide variety of plants by sucking the sap and as a result the plant is severely weakened distorting growth. Evidence of their existence can be seen as the growth of black, sooty moulds and or a sticky substance (honeydew) on foliage. Another sign of scale infestation is leaf blemish. Scales have hard shells and removal can be difficult hence the use of chemical application such as an Aphid spray, which softens the shell eventually killing them. The plant has to be isolated until the treatment is successful.

scale-pest

Sawfly Craesus septentrionalis – can be a real nuisance for those including myself whom have Betula species (Birch) as bonsai specimens because, the tender young leaves are prone to be ravaged by the Sawfly larvae running rampant all over the tree. As do the larvae of a large number of species of butterflies, moths and other insects. Female sawflies are so called because of the saw-like appendage at the tip of their bodies, which is used to cut slits into the leaves where the eggs are laid. There are different species of sawfly and the damage cause by their larvae is peculiar to each species for example. Some will leave notches or holes in leaves or devour the leaf leaving just its skeleton, others spin webs, leave galls and some will roll up a leaf completely. Sawfly are commonly found in bonsai for example. Conifer sawflies that feed on needles and bore into buds and shoots. Salix (Willow) the sawfly leaves distinctive red/brown galls, fruit and flowering – Prunus, (Cherry) Pyrus, (Pear) and Malus (Apple) are all affected by the sawfly.

The most common way to eradicate sawfly larvae is either removal manually or by using a horticultural soap as used for Aphids and Mealybugs, but the plant should be isolated so as not to infect others and to allow for the treatment to work.

the-sawfly

Sciarid flies often called Dark-winged fungus gnats are commonly found in moist environments including areas where house plants are situated. They thrive on damp soil conditions and can be seen scurrying over the soil, flying around and landing on stems, branches and leaves. Although they are known to be a pest in mushroom horticulture, they present no threat to bonsai plants nonetheless, they can be extremely irritating especially in a home environment. This large Diptera genus is one of the least studied mainly due to its small size 2mm and the difficulty in specific identification. It is said that more than 1,700 species have been described with an estimated 20,000 awaiting further study.

fungus-gnat

 

SpringtailsCollembola form the largest of the three lineages of modern hexapods the other two being Protura and Diplura these creatures are not classed as insects, because they are omnivores having internal mouth parts. They are small white or grey in colour and feed off the soil’s dead organic matter. When plants are watered and springtails are present, they are agitated and move rapidly and look unsightly. Springtails pose no threat to bonsai or other house plants, it is their very presence which can be irritating. If the desire is to eradicate these creatures, one can water the plants from the bottom by immersing the container in water and/or reduce the amount of water. But water reduction may not be conducive to some plant species, hence a careful balance should be maintained.

springtails

 

The above mentioned pests and diseases are common to bonsai horticulture, they are but a few of the many thousands that are in existence and to further research them would involve eons of time. Nevertheless, over the past decades horticulturists and scientists have done much of the spade-work hence it is not that difficult to find the answer one is looking for a particular problem. But it pays to be vigilant and inspect your bonsai specimens on a regular basis to ensure they remain in a healthy condition. As the old saying goes – ‘Prevention is better than cure’.

Another factor to consider is the soil composition, because bonsai are confined to a relatively small quantity of soil and this growing medium has to fulfill its needs. It must be able to retain water yet have good drainage and have the ability to allow for air circulation, without this basic criteria the tree will suffer. Soil contains a multitude of living organisms that consume, digest, and cycle nutrients. These living organisms include archaea, bacteria, actinomycetes, fungi, algae, protozoa, and a wide range of insects for example. Mites, nematodes, earthworms and ants all of which are important to the vitality of a soil composition.

Soil in a bonsai pot does not last indefinitely, it decays over a period of time due to the deterioration of living organisms and once expired it is unable to support the tree in order to sustain health and growth. This is when the tree is most vulnerable and attack from pests and disease can quickly take hold. Having said this one may think that a bonsai has to be re-potted every year – not only is this a misconception, it is unnecessary. A tree in a pot or container planted in year one will take at least 2 to 4 years to establish itself although much depends on the species and its growth rate. This can be assessed by teasing the tree out from its container and checking the root ball. If the roots are densely packed with little soil in situ, then it will probably need re-potting alternatively if what is seen is the opposite, then it can be re-placed and left for another season.

For example, one may think that this 13 year old Cotoneaster Lucidus (23cm) planted in a shallow pot (3.5cm x 22cm) would have a substantial root ball and become ‘pot-bound’ after one season. But this specimen is not a prolific grower either above or below the soil level nonetheless, it is inspected bi-annually in the spring. If there is room for the roots to develop it is returned to the pot unmolested and left to grow, but will be fed on a regular basis to ensure the nutrient up-keep. Root pruning and soil change will take place either in year 3 or 4. The next article ‘The need for stratification’ will probably be posted on 29th of January. Until next time BW, N.

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