Ipomoea decemcornuta O'Donell

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

372. Ipomoea decemcornuta O'Donell , Lilloa 26: 366. 1953. ( O’Donell 1953a: 366)

Type.

MEXICO. Est. México, Temascaltepec, Nanchititla, G.B. Hinton 4991 (holotype US00111386, isotypes GBH, GH, F, K, MICH).

Description.

Climbing herb, glabrous or with a few hairs at the nodes. Leaves petiolate, 5.5-17 × 4.5-12.5 cm, ovate, cordate, finely acuminate, terminating in a long hair-point, adaxially with a few appressed hairs, abaxially glabrous; petioles 3.5-6 cm. Inflorescence of pedunculate axillary cymes; peduncles 2-6 cm, winged; bracteoles 1-3 mm, oblong-lanceolate, caducous; pedicels 3-4.5 mm; sepals glabrous, outer 2.5-3 mm, oblong-elliptic, obtuse and mucronate, abaxially with three wings terminating in mucros c. 3 mm long, inner 3-3.5 mm, elliptic, obtuse with a single wing terminating in a mucro, middle sepal 2-winged; corolla 2.5-3 cm long, funnel-shaped, tube white, shallowly lobed, lobes probably purple, glabrous. Capsules subglobose,> 3 mm wide, rostrate, glabrous; seeds not known.

Distribution.

Endemic to central Mexico, occurring in a few scattered localities between 1000 and 2000 m.

MEXICO. Est. México: type collection. Michoacán: Puerto Zarzamora, Coalcomán, G.B. Hinton 12271 (K). Oaxaca: km 662, Piedra Larga a Miahuatlan, R. Cedrillo 1825 (MEXU). Sinaloa: Sierra Surutato, H.S. Gentry 6477 (ARIZ, MEXU).

Note.

The strongly winged peduncles are very distinct as are the dentate (sometimes described as winged) sepals. The latter suggests a connection with Ipomoea tentaculifera and forms of I. pedicellaris , rather than the Quamoclit Clade, in which it has been sometimes placed. The funnel-shaped, purplish corolla with a white tube and included stamens and 2-locular ovary also rule out the latter. The placement here is uncertain, being based on an incomplete molecular sequence.