1. Malus ioensis (Alph. Wood) Britton in N. L. Britton and A. Brown, Ill. Fl. N. U.S. 2: 235. 1897.
Prairie or Iowa or western crabapple
Pyrus coronaria Linnaeus var. ioensis Alph. Wood, Class-book Bot. ed. s.n.(b), 333. 1861; Malus angustifolia (Aiton) Michaux var. spinosa (Rehder) C. F. Reed; M. coronaria (Linnaeus) Miller subsp. ioensis (Alph. Wood) Likhonos; M. coronaria var. ioensis (Alph. Wood) C. K. Schneider; M. ioensis var. bushii Rehder; M. ioensis var. creniserrata Rehder; M. ioensis var. palmeri Rehder; M. ioensis var. spinosa Rehder; M. ioensis var. texana Rehder; P. ioensis (Alph. Wood) L. H. Bailey
Trees, sometimes shrubs, (20–)40–60(–100) dm. Stems 6–45 cm diam.; bark dark reddish brown to gray, with narrow reddish brown scales, sometimes glaucous when young; young branches reddish gray, tomentose, becoming reddish brown or dark brown and glabrous or slightly puberulous; flowering shoots becoming spurs or spiny thorns, 10–60 mm. Buds reddish brown, ovoid, 3–4 mm, scale margins tomentose. Leaves conduplicate in bud; heteromorphic; stipules deciduous, narrowly lanceolate, 3–8 mm, apex acute; vigorous shoot leaves: petiole 15–30 mm, tomentose; blade ovate, sometimes triangular-ovate or oval, 3–9(–12) × 1.5–4(–6) cm, base cuneate to rounded, margins usually lobed, serrate or crenate-serrate, sometimes doubly serrate, apex acute, broadly acute, or rounded, abaxial surface tomentose (villous only on veins), adaxial glabrous or slightly villous; flowering shoot leaves: petiole 5–20(–25) mm, tomentose, sometimes puberulent; blade elliptic, oval, or ovate, 2–5 × 1–2 cm, base cuneate or rounded, sometimes truncate-rounded, margins lobed or unlobed, serrate, doubly serrate, or crenate-serrate, apex acute, broadly acute, or rounded, abaxial surface usually tomentose, adaxial glabrous. Panicles corymblike; peduncles absent; bracteoles sometimes persistent, filiform, 3–10 mm. Pedicels 15–30 mm, tomentose, sometimes puberulent or sparsely strigose. Flowers ˂fragrant˃, 35–50 mm diam.; hypanthium tomentose; sepals triangular, 3–7 mm, equal to tube, apex acuminate, surfaces hoary-tomentose; petals pink, sometimes fading white, oblong to narrowly obovate, (11–)14–20(–22) mm, claws (2–)3–4 mm, margins entire, sinuate, or fimbriate, apex rounded; stamens 20, 8–16 mm, anthers rose before dehiscence; styles 5, connate basally, 9–15 mm, ± equal to stamens, tomentose in proximal 1/3. Pomes green, sometimes yellow, depressed-globose, sometimes globose, 20–30 mm diam., ˂greasy, waxy˃, cores not enclosed at apex; sepals persistent, erect; sclereids abundant surrounding core. Seeds dark brown. 2n = 34, 51, 64.
Flowering Apr–May; fruiting Sep–Oct. Woods, thickets, barrens, hillsides, stream and lake banks, flood plains, roadsides, open fields, fence lines; 100–300 m; Ark., Ill., Ind., Iowa, Kans., Ky., La., Mich., Minn., Mo., Nebr., Ohio, Okla., S.Dak., Tex., Wis.
The fruit of Malus ioensis is extremely acrid in taste, and it has a high pectin content that allows it to be made into a clear yellow jelly. The beautiful, fragrant flowers provide a pleasant show in spring. Double-flowered forms have been selected for cultivation: Bechtel’s crab and forma fimbriata A. D. Slavin. This species flowers later than the cultivated apple in most regions; artificial hybrids have been documented. Malus ×soulardii (L. H. Bailey) Britton (Pyrus ×soulardii L. H. Bailey) is a hybrid between M. ioensis and M. pumila.