Ipomoea ancisa House

Wood, John R. I., Munoz-Rodriguez, Pablo, Williams, Bethany R. M. & Scotland, Robert W., 2020, A foundation monograph of Ipomoea (Convolvulaceae) in the New World, PhytoKeys 143, pp. 1-823 : 1

278. Ipomoea ancisa House , Ann. New York Acad. Sci. 18 (6): 187. 1908. (House 1908b: 187)

Type.

MEXICO. Chihuahua, below Pacheco, E.W. Nelson 6276 (holotype US059993, isotypes GH, K, NY).

Description.

Erect perennial herb or subshrub to 1.5 m, often much branched, glabrous in all parts. Leaves shortly petiolate, up to 11 cm long, ± pinnately divided into filiform segments 1.5-8 × 0.05-0.1 cm; petioles 0.5-0.8 cm. Inflorescence of long-pedunculate, solitary or paired axillary flowers; peduncles 5-11 cm long, usually straight and rather stout; bracteoles ovate-deltoid, 1-2 mm long, deciduous; pedicels 1-2 cm, in fruit widening upwards and becoming recurved; sepals slightly unequal, outermost 5-7 × 4.5-6 mm, broadly ovate to suborbuicular, rounded, with broad scarious margins; inner conspicuously larger 8-10 × 7-8 mm, broadly elliptic, rounded, margins broad, scarious but the midvein extending to apex; corolla 9-10 cm long. funnel-shaped, glabrous, white to pale pink, limb entire, 8 cm diam. Capsules subglobose, 15-16 mm, glabrous; seeds 7-8 × 6 mm, glabrous.

Distribution.

Locally common in northern Mexico in the Chihuahua-Sonora border areas at around 1400-2000 m, where it grows in very dry oak woodland on rocky slopes. Endemic to Mexico.

MEXICO. Chihuahua: Mun. De Madera, R. Spellenberg 13835 (ARIZ, NMC); Río Mayo, H.S. Gentry 2648 (K, MEXU); Pacheco, Bowman Ranch, J. Spencer & N.D. Atwood 644 (K). Sonora: Mun. Yécora, Van Devender & Reina G. 2000-663 (ARIZ); Cañon de Huépari, S.S. White 2692 (MEXU); 10.3 miles E of Yécora, M. Fishbein et al. 2546 (ARIZ, MEXU).

Note.

Sometimes treated as a form of Ipomoea sescossiana but distinguished by the much longer leaves with filiform leaf segments <1 mm in width. Molecular studies raise doubts about the distinctness of these two species, although they are easily separated morphologically.