The taxonomy of the genus Malus is very confused - it has been revised on several occasions, with some authors placing species within the genus Pyrus. Recent morphologic work has suggested that Malus be retained as a separate genus based on fully adnate carpels and deeply inferior ovaries, with molecular evidence providing support. However, cultivation, hybridization, and introgression have led to hundreds of species being named within Malus and there is no clear agreement as to the number of accepted distinct species, or indeed the appropriate name for many of them. The genus requires a comprehensive worldwide revision[].

Common Name: Pillar Apple

General Information

Malus tschonoskii is a deciduous tree of erect, open, rather pyramidal habit; it can grow 9 - 12 metres tall.
The tree is harvested from the wild for local use as a food and source of wood. The plant is of potential value in breeding programmes of the cultivated apple, and it is also often grown as an ornamental, being valued especially for its autumn colour.
The plant is classified as 'Data Deficient' in the IUCN Red List of Threatened Species(2013)[].

Known Hazards

Although no specific information has been seen, the seed and other parts of the plant (but not the fruit) are likely to contain cyanogenic glycosides. When injested, these compounds break down in the digestive tract to release cyanide. Used in small quantities in both traditional and conventional medicine, this exceedingly poisonous compound has been shown to stimulate respiration, improve digestion, and promote a sense of well-being[]. It is also claimed by some to be of benefit in the treatment of cancer - though this claim has been largely refuted.
In larger concentrations, however, cyanide can cause gasping, weakness, excitement, pupil dilation, spasms, convulsions, coma and respiratory failure leading to death[].
The levels of toxin can be detected by the level of bitterness:- sweet almonds, for example, contain only very low levels of it and are safe to eat in quantity, whilst bitter almonds (which are used as a flavouring in foods such as marzipan) contain much higher levels and should only be eaten in very small quantities. Great caution should be employed if the taste is moderately to very bitter[].

Botanical References

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Range

E. Asia - Japan (Honshu, Kyushu, Shikoku)

Habitat

Woods in C. Japan[, ].

Properties

Conservation Status	Data Deficient
Edibility Rating
Other Uses Rating
Habit	Deciduous Tree
Height	10.00 m
Pollinators	Insects
Cultivation Status	Wild

Cultivation Details

An easily grown plant, it succeeds in most fertile soils, preferring a moisture retentive well-drained loamy soil[, ]. Grows well in heavy clay soils. Prefers a sunny position but succeeds in partial shade though it fruits less well in such a situation[, ].
Often planted as an ornamental[]. This species does not flower very copiously, and its fruits have no attraction in colour, but the leaves assume a wonderful autumnal mixture of colours - bronze, crimson, orange, purple and yellow. The fruits are almost non-existent, making it an ideal tree for roadside planting where the fruit would be a menace. It is said that no other crab-apple makes such a valuable contribution of leaf colour in the autumn[, ].
The fruit is a good wildlife food source, especially for birds[].
Cross-compatibility amongst the different species of Malus is common. Hybridization can occur naturally in botanical gardens and in the wild, or artificially through breeding[, ].
Polyploid forms and asexual seed production (apomixis) occur in some species[].
Plants in this genus are notably susceptible to honey fungus[].

Edible Uses

Fruit - raw or cooked[, ]. A gritty texture[]. A reasonable size, about 2 - 3cm in diameter[], but the fruit is not freely produced[, ]. A tree at Kew is fruiting well, producing fruits about 30mm in diameter and these fruits can hang on the tree all winter[]. Even when harvested in February the fruits were quite firm, slightly juicy with a strong acid flavour rather like a lemon[].

Medicinal

None known

Other Uses

This species is a secondary genetic relative of the cultivated Apple Malus domestica and so has potential for use as a gene donor for crop improvement[].

We do not have a specific description for the wood of this species - the following is a general description for the wood of this genus:-
The heartwood is reddish-grey; the 12 - 30 rings of sapwood are a light reddish. When steamed, the wood becomes reddish brown to dark red-brown. The wood is hard, but has a tendency to warp. It is very difficult to splitd and is difficult to work, but is easily stained and polished. The timber converts cleanly but is moderately hard to saw. A clean finish is produced normally, but a reduction of the cutting angle to 20° is an advantage to planing. The wood is generally of too small a size for commercial exploitation but, where larger sizes are attained the wood has been used for making a wide range of items, including furniture, mallet heads, umbrella handles, cog wheels, pianos, tools etc, and also for turnery[, , ].
The wood of Malus species generally makes a good fuel[, ].

Propagation

Seed - best sown as soon as it is ripe in the autumn in a cold frame. It usually germinates in late winter. Stored seed requires stratification for 3 months at 1°c and should be sown in a cold frame as soon as it is received[]. It might not germinate for 12 months or more. Prick out the seedlings into individual pots as soon as they are large enough to handle. If given a rich compost they usually grow away quickly and can be large enough to plant out in late summer, though consider giving them some protection from the cold in their first winter. Otherwise, keep them in pots in a cold frame and plant them out in late spring of the following year.
Cuttings of mature wood, late autumn in a frame[].