Ipomoea expansa

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

307. Ipomoea expansa McDonald, Brittonia 34: 336. 1982. (McDonald 1982: 336)

Type.

MEXICO. Guerrero, 3.6 miles N of turnoff to San Vicente de Benitezon road from Atoyac to El Paraíso, J.A. McDonald 185 (holotype TEX00372564, isotypes MEXU, TEX).

Description.

A slender trailing or twining perennial to 8 m, stems becoming woody. Leaves petiolate, or subsessile on fertile branches, 2.5-10 × 1-7 cm, often somewhat dimorphic, ovate to broadly lanceolate, cordate, hastate or sagittate with rounded or acute auricles, sometimes with dentate lobes, apex acuminate, glabrous; petioles 1-6 cm. Flowers solitary or paired, axillary; peduncle 0.5-2 cm, often penetrating the leaf sinus; bracteoles minute, c. 1 mm long; pedicels 8-30 mm, often stouter than peduncle; sepals slightly unequal, glabrous, oblong-elliptic, obtuse, margins white, scarious, outer 3-5 × 2.5-3 mm, inner 6 × 3 mm; corolla 4-6 cm long, pale blue, glabrous, subsalverform, flaring upwards, the basal cylindrical tube 1-1.5 cm long, limb 3-3.5 cm diam. Capsules conical, 11 × 7 mm, glabrous; seeds up to 4, 4-5 × 3-4 mm, minutely puberulent.

Illustration.

McDonald (1987c: 82).

Distribution.

A rare species of disturbed areas on the southern slopes of the Sierra Occidental growing in moister areas than Ipomoea puncticulata .

MEXICO. "Sierra Madre", E. Langlassé 903 (K, P). Guerrero: Atoyac, El Ranchito, J.C. Soto Nuñez & E.M. Martínez 5109 (MEXU). Oaxaca: Pochutla Dist., Concordia, E. Makrinius 841 (US); Tlaxiaco, Cerro Yucuntusu, M. Mendoza 134 (IEB); Etla, San Felipe Tejalapa, C. Cervantes-M 149 (MEXU).

Note.

Very close to Ipomoea puncticulata differing in the larger, blue-coloured corolla with a distinct cylindrical basal tube up to 1.5 cm long. The leaves are often dimorphic, differing in appearance on trailing or twining stems.