Ipomoea bombycina (Choisy) Benth. & Hook

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

81. Ipomoea bombycina (Choisy) Benth. & Hook f. ex Hemsl., Biol. Cent.-Amer., Bot. 2: 384. 1882. (Hemsley 1882: 384)

Bombycospermum mexicanum C. Presl , Reliq. Haenk. 2: 137, t. 71. 1835. (Presl 1831-35: 137), non Ipomoea mexicana A. Gray (1878) . Type. MEXICO (west). Haenke s.n. (PR?, n.v.).

Batatas bombycina Choisy in A.P. de Candolle , Prodr. 9: 340. 1845. (Choisy 1845: 340). Type. Based on Bombycospermum mexicanum C. Presl

Type.

Based on Bombycospermum mexicanum C. Presl

Description.

Woody liana from a rough, furrowed hypocotyl, stem with yellowish bark, pubescent and scabrous-pustulate. Leaves petiolate, 2.5-7.5 cm, ovate-rhomboid, acute, margin somewhat undulate, base subtruncate and cuneate onto the petiole (sometimes asymmetric), adaxially glabrous, abaxially grey-tomentose, puncticulate, veins prominent; petioles 2-5 cm, pubescent, sometimes pustulate. Inflorescence of short leafy axillary racemes, sometimes reduced to tight clusters; rhachis 2-8 cm long, densely pubescent; bracteoles c. 5 mm long, linear, fugacious; pedicels 3-4(-8) mm; sepals 5-8 mm, grey-tomentose, subequal, outer ovate, acute, inner elliptic, obtuse; corolla 2.5-3.5 cm long, basal cylindrical tube 7-10 mm, then expanded, urceolate, tube cream with purplish veins, adpressed pilose, limb with short triangular lobes, c. 3 × 3 mm, yellowish-green. Capsules 15 × 8-10 mm, ellipsoid, glabrous; seeds 7 × 4 mm, blackish, densely woolly with hairs 2 cm or more long.

Distribution.

An uncommon endemic of southern Mexico.

MEXICO. Chiapas: Mun. Ocozocoautla de Espinoza, A. Shilom Tom 3761 (F). Guerrero: Acapulco, E. Palmer 370 (F, K, MO); ibid., F. Miranda 3342 (MEXU); Tecpan, E. Langlassé 939 (K). Jalisco: Tomatlán, Puerto Vallarta-Barra de Navidad, E.J. Lott 678 (FTG, MEXU, MO); La Huerta, M.G. Ayala 442 (MEXU); Coyuca-El Zapote, G.L. Webster & G.J. Breckon 16227 (MEXU). Oaxaca: Tapanatepec, D. Thomatis s.n. (K). Zacatecas: El Calabazal, E. Langlassé 479bis (K, P).

Notes. The corolla is consistently 3-3.5 cm long, not 2.5 cm, as stated by McDonald (1992) so corolla size is unreliable in separating this species from Ipomoea gesneriodes .

A night-flowering, possibly bat-pollinated species.

The specimen at MO ( H.C. Cutler 8414) from Ceará, Brazil, identified as Ipomoea bombycina by McPherson is leafless and flowerless and is almost certainly not this species. It might, for example, be I. eremnobrocha , which has similar seeds and is known from several states in NE Brazil.