66. Malacomeles (Decaisne) Decaisne, Ann. Gén. Hort. 23: 156. 1882.
[Greek malakos, soft, and melon, apple]
Christopher S. Campbell
Cotoneaster Medikus sect. Malacomeles Decaisne, Nouv. Arch. Mus. Hist. Nat. 10: 177. 1874, based on Nagelia Lindley, Edwards's Bot. Reg. 31: Misc. 40. 1845, not Naegelia Rabenhorst 1844 [Fungi]
Shrubs, 10–30[–50] dm. Stems 1–20, ascending, ˂much branched, often ± twisted, young stems terete, closely villous, smooth˃; bark brown or gray, ˂young stems not hairy˃; long shoots present, short shoots sometimes present; unarmed; grayish- or whitish-tomentose, sometimes glabrate; ˂overwintering buds tomentose˃. Leaves drought-deciduous or persistent, cauline, simple, ˂slightly conduplicate˃; stipules tardily deciduous or ± persistent, free, lanceolate, ˂glandlike˃, margins entire; petiole present; blade elliptic or oblong-ovate to orbiculate, 0.5–1.5[–3.1] cm, leathery, margins flat, denticulate or entire, ˂teeth gland-tipped˃, venation pinnate, abaxial surface tomentose, adaxial ± glabrous. Inflorescences terminal ˂on leafy shoots of season˃, 1–5[–7]-flowered, corymbs [panicles], axes glabrous or hairy; bracts absent; bracteoles sometimes present. Pedicels present. Flowers: perianth and androecium epigynous, 10 mm diam.; hypanthium campanulate [urceolate], (2–)3–4 mm, distally copiously white-tomentose; sepals 5, spreading, nearly orbiculate (inner broadly deltate); petals 5, white, round or kidney-shaped, ˂base short-clawed˃; stamens [8–]14–20[–22], longer or shorter than petals; carpels 2 or 3[–5], barely connate or distinct, adnate to proximal 1/2–4/5 of hypanthium, ˂ovary appearing 4–10-loculed by false partitions˃, densely hairy, styles ˂2 or 3˃, ventral, distinct; ovules 2 (separated by false partition). Fruits berrylike pomes, translucent, vivid pink, drying purplish black, globose, 6–10 mm, glabrous; ˂flesh whitish˃; hypanthium persistent; sepals persistent, erect or recurving; carpels cartilaginous; styles persistent. Seeds 4–6(–10).
Species 2 (1 in the flora): United States, Mexico, Central America.
Malacomeles shares with Amelanchier and Peraphyllum the feature of false partitions within the carpels; the partitions partially divide the locules and make the fruit appear to have twice as many locules as the number of carpels (G. N. Jones 1945; K. R. Robertson et al. 1991; J. R. Rohrer et al. 1991). Sequences from multiple chloroplast and nuclear genes indicate that Malacomeles is closely related to Amelanchier and Peraphyllum (C. S. Campbell et al. 2007).
The other species in the genus, Malacomeles nervosa (Decaisne) G. N. Jones, is known from Nuevo León, Mexico south to Guatemala.
SELECTED REFERENCES Hunt, D. R. and C. King. 1978. Amelanchier denticulata (Rosaceae). Bot. Mag. 182: 20–23. Jones, G. N. 1945. Malacomeles, a genus of Mexican and Guatemalan shrubs. Madroño 8: 33–39.
