6. Malus ioensis (Alph. Wood) Britton (prairie crab apple, wild crab)

M. ioensis var. bushii Rehder

M. ioensis var. palmeri Rehder

Pyrus ioensis (Alph. Wood) L.H. Bailey

Pl. 533 c, d; Map 2460

Plants shrubs or small trees to 8(–10) m tall, sometimes colonial from root suckers. Branchlets mostly thorn-tipped. Twigs short-hairy. Leaf blades folded lengthwise during development, 4–10 cm long, 2–3 times as long as wide, oblong-ovate to broadly elliptic, angled to broadly angled at the base, angled or tapered to a sharply pointed tip, the margins somewhat irregularly, sharply toothed, those of at least the larger leaves usually shallowly lobed, densely woolly on both surfaces when young, the upper surface sometimes becoming nearly glabrous at maturity. Flower stalks and hypanthia finely woolly. Calyces persistent at fruiting, the sepals 6–9 mm long, narrowly triangular, the outer surface glabrous or very sparsely hairy, the inner surface densely woolly. Petals 1.2–2.0 cm long, the body obovate to ovate, short-tapered to a short stalklike base, pink or pinkish-tinged to nearly white at flowering, pinkish-tinged in bud, often fading to white with age. Anthers pink to orangish red. Styles 5, the stigmas narrowly club-shaped. Fruits 2–3 cm long, green to yellowish green, often somewhat glaucous. 2n=34. April–May.

Scattered nearly throughout the state (South Dakota to Texas east to West Virginia and Mississippi). Upland prairies, sand prairies, glades, savannas, edges of mesic upland forests, banks of streams and rivers, and edges of bottomland forests; also old fields, fencerows, old mines, railroads, roadsides, and open, disturbed areas.

Malus ioensis is closely related to and perhaps not distinct from M. angustifolia and M. coronaria. For discussion of problems with the taxonomy of these species, see the discussion of M. coronaria.

Prairie crab is a conspicuous and attractive native species. Steyermark (1963) noted that the foliage turns a dull rose color blended with yellow and dull green at the end of the growing season. He also noted that plants have deep-seated rootstocks, making them difficult to transplant, but that they are propagated relatively easily from seeds. A horticultural variant that is slightly later-blooming and has doubled flowers (f. plena Rehder) is sold under the name Bechtel’s crab. The fruits are sometimes used in jams and jellies, and early settlers fermented the fruits into a cider.

The Soulard crab, M. ×soulardii (L.H. Bailey) Britton (Pl. 533 f) arose as a spontaneous hybrid between the cultivated apple (M. domestica) and the native wild crab apple, M. ioensis. According to L. H. Bailey (1911), it was first discovered in Illinois near the city of St. Louis, Missouri, but several discordant accounts existed as to the credit for its discovery. The hybrid has leaves similar to those of M. ioensis, but has a larger fruit. The fruit is too tart to be eaten raw, but can be used in baking and preserves.