Ipomoea decasperma Hallier

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

260. Ipomoea decasperma Hallier f., Bull. Herb. Boiss. 5: 386. 1897. (Hallier 1897a: 386)

Ipomoea oreophila House , Ann. New York Acad. Sci. 18: 195. 1908. (House 1908b: 195). Type. MEXICO. Hidalgo, Lena Station, C. G. Pringle 10034 (holotype GH00054522, isotypes BM, CM, F, K, M, MEXU, NY, S, US).

Ipomoea emetica auct.

Type.

MEXICO. [Jalisco], Zacoalco, Valley of Mexico, E. Bourgeau 797 (lectotype G00342886 ex Herb. DC, designated here; isolectotypes P, S).

Description.

Twining perennial to 1 m from a large root tuber, stems pubescent. Leaves petiolate, 2-8.5 × 1-5.3 cm, ovate-panduriform to subreniform, base cordate to subsagittate, auricles rounded to subacute, somewhat spreading, apex acute to obtuse, mucronate, margin undulate or with 1-2 large lateral teeth or 3-5-lobed, sparsely pubescent on both surfaces, abaxially paler; petioles 1.2-5 cm, pubescent. Inflorescence of solitary axillary flowers; peduncles 2-5.2 cm, pubescent; bracteoles 2-4 mm, linear, tardily deciduous; pedicels 5-14 mm, pubescent; sepals slightly unequal, pubescent, strongly accrescent in fruit; outer 7-10 × 4-7 mm, ovate-deltoid with a broad truncate to subcordate base, acuminate, inner c. 1 mm longer, narrower and basally cuneate; corolla 3.5-4 cm long, funnel-shaped, nearly glabrous but with a few hairs towards the apex of the midpetaline bands, tube whitish, limb deep pink, limb c. 3 cm diam. Capsules 10-12 mm, globose, 5-locular with up to ten seeds; seeds lentil-shaped, 4 mm, densely pubescent with short stiff hairs.

Distribution.

Endemic to central Mexico growing in secondary Quercus woodland at 1900-2500 m.

MEXICO. Durango: E. Palmer 592 (BM, K, S); Súchil, S. González & Y. Herrera 1341(MEXU). Est. México y Dist. Fed.: Valley of Mexico, A. Schmitz 108 (BM, W); Mun. Huehuetoca, J. Rzedowski 34330 (FTG, MEXU); Temascaltepec, G.B. Hinton 6525 (F), 8442 (K), 8454 (K). Guanajuato: Pénjamo, La Loma, E. Pérez & J. Becerra 4009 (IEB, MO); San Felipe, Los Altos de Ibarra, R. & J.D. Galvín 2298 (IEB); Coroneo, E. Carranza 5345 (IEB, MEXU). Hidalgo: type of Ipomoea oreophila . Jalisco: Zacoalco, Vale of Mexico, E. Bourgeau 497 (P, G), 728 (K, P, S), 792 (G, P); Michoacán: Morelia, G. Arsène 3486 (G, MO), 5972 (G, MO); ibid., Cerro del Aguila, G.C. Tenorio et al. 2247 (IEB, K, MEXU). Querétaro: Amealco de Bonfil, E. Carranza & I. Silva 6180 (IEB, MEXU); Huimilpan, E. Argüelles 2613 (IEB, MEXU).

Notes. Very distinct because of the 10-seeded capsule, leaf shape and truncate-based outer sepals. A record from Sonora: fide Felger et al. (2012) seems unlikely.

O’Donell annotated specimens of this species as Ipomoea emetica Choisy and was followed in this by Austin and Huáman (1996). The case for rejecting the name, I. emetica in favour of I. decasperma was made by Wood and McDonald (2018).