1. Aronia melanocarpa (Michx.) Elliott (black chokeberry)

Photinia melanocarpa (Michx.) K.R. Robertson & J.B. Phipps

Pyrus melanocarpa (Michx.) Willd.

Pl. 524 a–d; Map 2408

Plants shrubs, 0.3–3.0 m tall. Stems lacking spines and thorns. Bark reddish brown to grayish brown, with inconspicuous lighter lenticels, smooth or somewhat roughened. Leaves alternate, rolled during development, mostly relatively short-petiolate, the petioles with scattered small peglike glands in the groove on the upper surface. Stipules 2.5–3.5 mm long, herbaceous, linear to narrowly oblong, the margins with reddish glandular teeth, shed soon after the leaves develop. Leaf blades 1.5–9.0 cm long, simple, unlobed, elliptic to broadly elliptic, mostly long-tapered at the tip and base, the margins finely and sharply toothed, the upper surface glabrous but with a line of small peglike reddish purple glands along the midrib (and sometimes also the main lateral veins), the undersurface glabrous or finely hairy when young. Inflorescences branched clusters at the tips of normal branches, produced as the leaves uncurl, the axis glabrous, the flowers with a small linear bract toward the middle of the stalk, this shed before the flower opens. Flowers epigynous, the hypanthium fused to the ovaries, glabrous. Sepals 5, 1.3–1.8 mm long, spreading, triangular, the margins thin and somewhat irregular or glandular, the inner surface densely woolly, persistent at fruiting. Petals 5, 4–7 mm long, broadly obovate to nearly circular, white, occasionally tinged with pink. Stamens 15–20, the anthers yellow. Pistil 1 per flower. Ovary inferior, the tip densely woolly, with 5 locules, each with 1 ovule. Styles 5, fused toward the base, the stigmas more or less capitate. Fruits berrylike pomes, 7–10 mm long, globose, glabrous, purplish black to black at maturity, with (3–)5 easily exposed seeds embedded in the “core” of inconspicuous papery carpel wall remains and the fleshy portion. 2n=34. April–May.

Uncommon, known only from the Crowley’s Ridge Section of the Mississippi Lowlands, in Stoddard County (eastern U.S. west to Minnesota and Arkansas; Canada). Margins of acid seeps.

The fruits of this species are relatively tart when fresh, but have been used in jellies. This species was first discovered growing in the state by Steyermark (1958a), who catalogued an interesting series of species restricted in Missouri to the sandy ravines along the base of Crowley’s Ridge. Steyermark (1963) and some other authors have included Aronia in an expanded concept of the genus Pyrus, but morphological studies (Phipps et al., 1991; K. R. Robertson et al., 1991) have suggested that this small genus may be more closely allied to the otherwise Asian genus, Photinia Lindl.

The other member of the genus, A. arbutifolia (L.) Pers. is an eastern and southern species whose range in Arkansas approaches southern Missouri (Hardin, 1973). It differs from A. melanocarpa in its more or less hairy leaves, red fruits (that persist on the plants for far longer than do those of A. melanocarpa), and leaves that turn bright red (rather than brown) in the autumn.