Ipomoea macdonaldii E. Carranza

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

138. Ipomoea macdonaldii E. Carranza , Brittonia 63: 66. 2011. (Carranza 2011: 66)

Type.

MEXICO. Oaxaca, Pochutla, Mun. Santa Maria Huatulco, E. Carranza et al. 7430 (holotype IEB0225154, isotypes IEB, MEXU, NY).

Description.

Twining perennial herb 6-10 m high, stems glabrous. Leaves petiolate, 6.5-12 × 4-10 cm, ovate, sometimes 3-lobed to nearly halfway, acuminate, mucronate, base truncate and briefly cuneate onto the petiole, glabrous except for the pilose margin; petioles 2-8 cm. Inflorescence of long-pedunculate compound axillary cymes; peduncles 10-28 cm, glabrous; bracteoles 1.5-4 mm, ovate, caducous; secondary peduncles 1.5-4 cm; tertiary and quaternary peduncles slightly shorter; pedicels 17-30 mm; sepals slightly unequal, glabrous, coriaceous, outer 5.5-6.5 × 2.5-4 mm, oblong-elliptic, convex, obtuse, scarious-margined, inner 7-9 × 4-6 mm, elliptic-obovate, truncate or retuse; corolla c. 5 cm long, hypocrateriform, the tube subcylindrical, 4-5 cm long, white, glabrous, the limb lobed, stamens exserted; Capsules 11-13 × 8 mm, ellipsoid, the style base persistent; seeds 5-7 × 3 mm long, the margins pilose with hairs 10 mm long.

Illustration: Carranza (2011: 66).

Distribution.

At low altitudes below 200 m near the coast in the coffee zone in Pochutla region of Oaxaca,

MEXICO. Oaxaca: Mun. Santa Maria Huatulco, A. Sánchez Martínez et al. 1210 (IEB, MEXU); Mun. Santiago Astata, M. Elorsa 7526 (MEXU); Mun. San Carlos Yautepec, N. Velasquez et al. 453 (MEXU); Mun. San Miguel del Puerto, J. Riveira et al. 2003 (MBM); ibid., S.H. Salas & A. Sánchez 6133 (IEB).

Notes.

This species is very close to Ipomoea lottiae differing principally in the nearly glabrous leaves (except pilose margins) and exserted stamens. It also resembles Ipomoea proxima but is distinguished by the hypocrateriform corolla.

The following specimens from central Mexico are identical with I. macdonaldii , even to the pilose leaf margins, except for the funnel-shaped corolla. They differ from Ipomoea pseudoracemosa in the relatively long peduncle 3-13 cm in length as well as the presence of leaves at anthesis. The leaves are petiolate, ovate-deltoid, 4-8 × 4-7 cm, acuminate to a shortly mucronate apex, the base subtruncate and very shortly cuneate onto a petiole 1.5-3.5 cm.

MEXICO. Est. México & Dist. Fed.: Temascaltepec, Guayabal, G.B. Hinton 8528 (F, GBH, K, MO), ibid., Tejupilco, G.B. Hinton 8554 (K). Michoacán: Coalcomán, G.B. Hinton 12464; Huetamo, G.B. Hinton 13324 (K).