Solanum scabrum subsp. scabrum Miller, Gard. Dict.

Olet, Eunice Apio, Heun, Manfred & Lye, Kåre A., 2006, A New Subspecies of Solanum scabrum Miller Found in Uganda, Novon: A Journal for Botanical Nomenclature 16 (4), pp. 508-511 : 509-510

1a. Solanum scabrum subsp. scabrum Miller, Gard. Dict. , ed. 8. 1768.

TYPE: U.S.A. Virginia. P. Miller s.n. (lectotype, BM).

Erect herb or subshrub ca. 0.7–1.2 m, with few branches spreading horizontally, moderately to densely pubescent with simple appressed eglandular hairs (pilose); stems purple or greenish purple, angled with prominent dentate wings. Leaves orbicular to broadly ovate, 10–14(16) × 6–13.5 cm; lamina purplish green or green with a purple tint; veins purple; leaf base cordate to truncate; leaf apex acute, subacute to obtuse, rarely cuspidate; leaf margin sinuate to entire or entire; petiole winged halfway up or not winged. Inflorescence umbellate to racemose or of extended cymes, sometimes branching once, 6- to 12(16)- flowered; peduncles at right angles with branch, 1.6–3(3.3) cm; pedicels reflexed or straight, 6– 10 mm. Corolla stellate, purple with dark green to yellowish green base, 11–14(16) mm wide; style 3– 4 mm, geniculate, rarely straight, exserted ca. 0.5– 2 mm beyond anthers, rarely absent; calyx campanulate, rarely stellate; anthers brown, purplish brown, or yellow with deep purple tint and dark purple middle, (2)2.5–3 mm long. Ripe fruits deep purple to black with deep blue to purple pulp, or deep purple to black with dark blue pulp, 10–15(16–17) mm broad; fruit cuticle thick and opaque; mature sepal lobes ovate, mature calyx reflexed away from berry, strongly adherent, persistent; fruits persistent on plant when ripe; fruit pedicel erect or reflexed; seeds creamish green to brown, (1.7)1.8–2.1 mm; stone cells absent.

The type of the autonymic subspecies is taken from a plant cultivated in Chelsea Physics Garden in London ( Miller, 1768). For more details on lectotypification see Henderson (1974) and Edmonds (1979).

Because this plant is so widely cultivated in the tropics of both hemispheres, it has previously been difficult to ascertain its origin (Edmonds & Chweya, 1997; Bukenya & Carasco, 1995). Today, it is probably most widely cultivated in West Africa ( Berinyuy et al., 2002), while in Uganda it is rare and is cultivated only in Kigezi, in southwest Uganda.

Notes on the type. The type of Solanum scabrum at BM is nearly 250 years old, but it is in excellent condition with flowers and young fruits. The only important character that cannot be observed is the size of the mature berry. However, with its winged spiny stem, it is noticeably different from subspecies laevis described below.

Vernacular name. Nswiga ya Kizungu (Lukiga).

Collections from Uganda (DNA-tested). Western region: Kigezi, Kabale distr., Rubanda co., Kachwekano farm, 10 km SW of Kabale town, 2001, E. A. Olet 48, 49 & 50 (MHU).

Collections from Uganda (not DNA-tested). Wes-Western region: Kigezi, Ruzhumbura, Bugangari, near habitation, Feb. 1949, J. W. Purseglove 2712 (K); Kigezi D.F.T., open waste places near cultivated plots, 28 Aug. 1972, P. M. Good e 3/72 (K).