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: Prairie Crab

General Information

Malus ioensis is a deciduous shrub, though more commonly a tree; it usually grows 4 - 6 metres tall but sometimes reaches 10 metres. The bole can be 6 - 45cm in diameter[]. The tree produces suckers and often forms thickets in the wild[].
The tree is harvested from the wild for local use as a food. It is grown as an ornamental in gardens.

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

, ,

Range

Central N. America - South Dakota to Michigan, south to Texas and Louisiana.

Habitat

Open woods, thickets, barrens, hillsides, stream and lake banks, flood plains, roadsides, open fields, fence lines; at elevations from 100 - 300 metres[].

Properties

Edibility Rating
Other Uses Rating
Habit	Deciduous Tree
Height	5.00 m
Growth Rate	Slow
Pollinators	Insects
Cultivation Status	Ornamental, 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. The plant has a preference for calcareous soils in the wild[], though the cultivar 'Plena' does not grow well in alkaline conditions[]. Prefers a sunny position but succeeds in partial shade though it fruits less well in such a situation[].
A slow-growing and short-lived species in the wild[], it produces suckers from the roots and often forms thickets[].
The beautiful, fragrant flowers provide a pleasant show in spring. Double-flowered forms have been selected for cultivation[].
This species is closely related to Malus coronaria[].
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[].
There are many named forms, selected for their ornamental value[].
The fruit is a good wildlife food source, especially for birds[]. The plant fruits very heavily in southern Britain[].
Plants in this genus are notably susceptible to honey fungus[].

Edible Uses

Fruit - raw or cooked[, , , ]. Harsh and astringent[, , ], it is best baked or made into preserves. It makes excellent jellies and cider[]. The fruit is extremely acrid in taste, and it has a high pectin content that allows it to be made into a clear yellow jelly[]. The green, sometimes yellow, globose fruit is 20 - 30cm in diameter[]. Up to 40mm in diameter[].

Medicinal

None known

Other Uses

Wood - heavy. Of no commercial importance[].
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[].