76. Ipomoea rupicola House, Ann. New York Acad. Sci. 18: 230. 1908. (House 1908b: 230)

Type.

MEXICO. Tamaulipas, Jonmave Valley, E.W. Nelson 4448 (holotype US332519, isotype GH).

Description.

Trailing or twining perennial from woody enlarged rootstock, stems thinly pubescent, eventually glabrescent. Leaves petiolate, small, 2-5 × 2-5 cm, ovate-deltoid, acuminate, cordate-hastate with relatively large, rounded, acute or shallowly bifid auricles, margin often undulate, pubescent, especially beneath; petioles 1-4 cm. Inflorescence of solitary flowers; peduncles 1-3 cm; bracteoles minute; pedicels 7-15 mm; sepals slightly unequal, oblong or oblong-elliptic, obtuse, puberulous, outer 8-10 mm, inner 10-13 × 6-8 mm with scarious margins; corolla 6-9 cm long, funnel-shaped, pubescent, limb 6 cm diam., bluish-purple. Capsules globose, rostrate, glabrous; seeds 8 × 5 mm, ellipsoid, densely lanate.

Distribution.

Arid rocky slopes and cliff faces, NE Mexico and adjacent parts of Texas.

MEXICO. Coahuila: Sierra del Pino, I.M. Johnston & C.H. Muller 385 (GH); Torreón, G.S. Hinton 25751 (GBH, TEX); zona de Laguna de la Leche, T. Wendt & E.J. Lott 1884 (MEXU). Nuevo León: Salinas Victoria, G.S. Hinton 24248 (GBH); Sierra de Lampazos, J.A. Villarreal et al. 9149 (IEB). Tamaulipas: Pueblo Viejo, 2 km S of Tampico, E. Palmer 428 (US); 25 km S of Tula, M.C. Johnston et al. 11134 (MEXU, MO); Tula, E. Pérez Calix 4259 (IEB).

UNITED STATES. Texas: Brewster, Brushy Creek, B.L. Turner & W. Dodson 23-167 (TEX); ibid., Mt Emory, B.H. Warnock 476 (TEX); Cameron Co., W.R. Carr & M. Pons 29898 (TEX); Hidalgo, La Joya, R. Runyon 2751 (TEX).

Note.

This species is characterised by the small pubescent leaves with undulate margins, solitary flowers and oblong puberulous sepals.