Ipomoea pruinosa McPherson

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

140. Ipomoea pruinosa McPherson , Contr. Univ. Michigan Herb. 14: 88. 1980. (McPherson 1980: 88)

Type.

MEXICO. Guerrero, Casa Verde to Xochipala, R. McVaugh 22192 (holotype MICH1000057, isotypes ENCB, MEXU).

Description.

Liana to 5 m, stems tomentose, eventually glabrescent. Leaves unknown, absent at anthesis. Inflorescence of compound axillary cymes borne towards the tips of branches; peduncles 0.2-0.6 cm, sericeous; bracteoles caducous, unknown; pedicels 2-9 mm, thickened upwards, sericeous; sepals subequal, ovate or ovate-elliptic, obtuse and sometimes mucronate, coriaceous, sericeous, outer 5-6 × 3-4 mm long, inner 6-7 × 5 mm, the margins broad, scarious; corolla 6.5-9 cm long, funnel-shaped, white with reddish midpetaline bands, sericeous, limb 4.5-7 cm diam., unlobed; stamens included. Capsules 12-15 mm long, oblong-ovoid, shortly rostrate, glabrous; seeds pilose on the margins.

Illustration.

McPherson (1980: 89).

Distribution.

A little known species, apparently endemic to Guerrero State in Mexico.

MEXICO. Guerrero: Casa Verde, H. Kruse s.n. [14/2/1970] (MEXU); Eduardo Neri, Venta Vieja, A. A. Aguilar 34 (MEXU); Zopilote canyon, Chilpancingo - Río Balsas, B. Mostul 1161A (OXF).

Note.

The large, nearly white, sericeous corolla, the subequal sericeous sepals and the included anthers distinguish this species, which is leafless when flowering. There is one leaf on Aguilar 34. It is 4.5 × 4 cm, suborbicular, abruptly acute, basally cuneate, glabrous, abaxially white, strongly reticulate.