3. Malus coronaria (L.) Mill. (wild crab, sweet crab apple)

Pyrus coronaria L.

P. coronaria var. lancifolia (Rehder) Fernald

Pl. 533 e; Map 2457

Plants shrubs or small trees to 5(–10) m tall, often colonial from root suckers. Branchlets mostly thorn-tipped. Twigs glabrous or nearly so. Leaf blades folded lengthwise during development, 3–10 cm long, 1.5–3.0 times as long as wide, broadly lanceolate to broadly ovate, broadly angled to rounded or shallowly cordate 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, the surfaces glabrous at maturity, the undersurface sparsely hairy when young. Flower stalks and hypanthia glabrous or sparsely hairy. Calyces more or less persistent at fruiting, the sepals 3–5 mm long, triangular to narrowly triangular, the outer surface glabrous or very sparsely hairy, the inner surface densely woolly. Petals 1.5–2.5 cm long, the body ovate to oblong-ovate, short-tapered to a noticeable stalklike base, pink or pinkish-tinged at flowering, often fading to white. 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=68. April–May.

Scattered in southeastern and central Missouri (eastern U.S. west to Wisconsin and Arkansas). Bottomland forests, mesic upland forests, banks of streams, margins of sinkhole ponds, and upland prairies; also roadsides.

Steyermark (1963) noted that the fruits of this species sometimes are used in jams and jellies, and that early settlers fermented the fruits into a cider.

The key characters will serve to adequately distinguish most but not all specimens of M. angustifolia, M. coronaria, and M. ioensis. These taxa are part of a polyploid complex within Malus sect. Chloromeles (Decne.) Rehder. Some authors have suggested that distinctions among the taxa are complicated not only by the variable morphology within them, but also because of past hybridization (K. R. Robertson, 1974). In a study of genetic variation within and between populations of American Malus species using allozyme markers, Dickson et al. (1991) found little variation within sect. Chloromeles and no genetic markers to distinguish any of the species. K. R. Robertson (1974) suggested that the three species present in Missouri should be maintained provisionally until more detailed taxonomic studies could be completed.