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: Oregon Crab

General Information

Malus fusca is a deciduous shrub or, more often, a tree that can grow 5 - 10 metres tall, occasionally reaching 20 metres. The bole is usually 20 - 30cm in diameter, occasionally to 40cm[, ].
The plant is harvested from the wild for local use as a food, medicine and source of wood. It is sometimes grown as an ornamental in gardens.
Malus fusca is known to be abundant and secure in British Colombia and California with reproducing populations reported from a number of protected areas across its native range. The plant is classified as 'Least Concern' 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

Western N. America - Alaska, Washington, Oregon, California.

Habitat

Scattered in open canopy forests, streambanks, upper beaches, shoreline thickets, estuary fringes, swamps and open canyons; at elevations up to 1,420 metres, but mainly below 250 metres[].

Properties

Conservation Status	Least Concern
Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Deciduous Tree
Height	8.00 m
Growth Rate	Slow
Pollinators	Insects
Cultivation Status	Wild

Cultivation Details

Requires a sunny position[]. A characteristic plant of nutrient-rich wetlands, growing in nitrogen-rich soils in moist to wet habitats[].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[]. This species often grows near the coast, where it often experiences salt spray[].
A very ornamental plant[], it is slow-growing in the wild[].
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[].
The fruit is a good wildlife food source, especially for birds[].
Plants in this genus are notably susceptible to honey fungus[].

Edible Uses

Fruit - raw or cooked[, ]. An agreeable sub-acid taste, it can be eaten out of hand or made into jellies, preserves etc[]. The fruit can be left on the tree until there have been some autumn frosts, this will soften the fruit and make it somewhat less acid[]. The fruit is rich in pectin so it can be added to pectin-low fruits when making jams or jellies[, ]. Pectin is also said to protect the body against radiation[]. The yellow to purplish-red, oblong to ovoid fruit is usually 6 - 10mm in diameter, occasionally to 20mm[, ].

Medicinal

Oregon crab was employed medicinally by several native North American tribes who used it to treat a variety of complaints[]. In particular, it gained a reputation with some tribes as a heal-all, especially useful for treating any of the internal organs[]. It is little, if at all, used in modern herbalism.

The trunk, bark and inner bark are antirheumatic, astringent, blood purifier, cardiac, diuretic, laxative and tonic[]. A decoction has been used in the treatment of coughs, stomach ulcers, dysentery, diarrhoea, rheumatism and consumption[]. The shredded bark has been used to treat blood spitting[].
A poultice of the chewed bark has been applied to wounds[]. An infusion of the bark is used as an eyewash[]. A decoction of the bark is used as a wash on cuts, eczema and other skin problems[].
An infusion of the bark, combined with wild cherry bark (Prunus sp.) has been used as a cure-all tonic[].

The juice scraped from the peeled trunk has been used as an eye medicine[].

The soaked leaves have been chewed in the treatment of lung problems[].

Other Uses

The fruit is a source of pectin[].

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[].