Ipomoea pseudoracemosa 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

139. Ipomoea pseudoracemosa McPherson , Contr. Univ. Michigan Herb. 14: 88. 1980. (McPherson 1980: 88)

Type.

MEXICO. Jalisco, 6.5 miles NE of Autlán, R. McVaugh & W.N. Koelz 1037 (holotype MICH1111340).

Description.

Liana, stems up to 5 m long, woody, pubescent, glabrescent. Leaves usually absent at anthesis, not certainly known. Inflorescence of shortly pedunculate axillary clusters of reduced cymes; peduncles 0.2-3 cm, pubescent; bracteoles 2-4 mm, deltoid, caducous; secondary peduncles 0.5-4 mm, glabrous; pedicels 5-17 mm, glabrous; sepals slightly to very unequal, suborbicular, obtuse, rounded or retuse, convex, coriaceous, glabrous or thinly comose at the apex, outer 2.5-4 × 3-4 mm, inner 4-6 × 6 mm, the margins scarious; corolla 5-7 cm long, funnel-shaped, white, glabrous; limb 3.5-6 cm diam.; stamens included. Capsules ovoid, 12-13 × 6-7 mm, glabrous; seeds 6 × 4 mm, long pilose on the margins with hairs 7-9 mm long.

Illustration.

McPherson (1980: 90).

Distribution.

Endemic to central Mexico on dry scrub-covered hills between 900 and 1500 m.

MEXICO. Sine data, E. Langlassé 862 (K, P). Est. México & Dist. Fed.: Temascaltepec, G.B. Hinton 5331 (K). Guerrero: Mina, G.B. Hinton 9815 (K), 10088 (K); Río de Oro-Zihuatanejo, C. Rafael Torres et al. 7741 (MEXU). Jalisco: San Cristóbal de la Barranca, R. McVaugh 22141 (MICH); Autlán, E. Carranza & I. Silva 7175 (IEB). Michoacán: Churumuco, I. Solorio Herrera 12 (IEB); ibid., G. Ibarra Manríquez 6657 (MEXU); La Huacana, V.W. Steinmann 3029 (IEB). Nayarit: 10 miles SE of Ahuacatlán, R. McVaugh & W.N. Koelz 728 (MICH). Zacatecas: Moyahua, Cerro La Cantarilla, E.D. Enriquez 816 (MEXU).

Note.

Distinguished from other similar species by the glabrous, funnel-shaped white corolla, very short peduncles and short, glabrous sepals. The type and all the specimens cited above are leafless so it is very difficult to characterise this species reliably.