Ipomoea pterocaulis

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

91. Ipomoea pterocaulis J.R.I. Wood & L.V. Vasconc., Kew Bull. 72 (9): 8. 2017. (Wood et al. 2017a: 8)

Type.

BRAZIL. Bahia, Morro do Chapeú, ca. 1 km após Lagoinha na Estrada para Cafarnaum, 11°41'01"S, 41°20'11"W, 902 m, L.P. de Queiroz, J.R.I. Wood & H. Huaylla 15957 (holotype HUEFS 209791, isotype OXF, K).

Description.

Vigorous twining plant decumbent in open ground or climbing over bushes to several metres, stems stout, prominently winged, glabrous. Leaves petiolate, 2.5-10 × 2-9 cm, ovate-deltoid, acute or obtuse, base shallowly cordate with a broad sinus and rounded to subacute auricles, margin undulate to slightly sinuate, both surfaces glabrous, abaxially paler with prominent veins; petioles 1.3-5.5 cm. Inflorescence of pedunculate axillary cymes; peduncles 2-12 cm; bracteoles 1-2 mm, lanceolate, caducous; secondary peduncles 1-2 cm; pedicels 3-5 mm; sepals subequal, glabrous, 13-15 × 7-10 mm, elliptic, obtuse or rounded; outer often reddish, inner with scarious margins; corolla (6-)8-9 cm long, glabrous funnel-shaped, tube white; limb 7-8 cm diam. Capsules 10 × 8-9 mm, ellipsoid, glabrous, muticous; seeds 6 × 4 mm, dark brown, glabrous except for long white hairs on angles.

Illustration.

Figure 59 .

Distribution.

An endemic species of the Brazilian Caatinga/Cerrado interface.

BRAZIL. Bahia: 14 km SW of Cansanção, R.M. Harley et al. 16476 (P, MO, NY); Mun. Abaira, 1.5 km de cidade, R.M. Harley et al. 53599 (HUEFS, RB); Mun. Bela Vista, Juremal, M.V. Moraes 676 (HUEFS); Mun. Ourolândia, 9 km de Umburanasca, J.G.A. do Nascimento et al. 620 (HUEFS). Pernambuco: Mun. Afrânio, Serra do Coboclo, E.P. Heringer et al. 266 (IPA).

Notes.

Superficially distinctive because of its large corolla and winged stem, this species has been identified as Ipomoea jalapa (L.) Pursh. However it is easily distinguished by its glabrous stem, sepals and corolla. The seed indumentum is also quite different in the two species.

R.M. Harley et al. 16476 is slightly different from the other collections in having shorter sepals about 10 mm long and is included with a degree of uncertainty.

C. Toleto Rizzini & A. Mattos Filho 1113 (RB, OXF) from Itaobim, Minas Gerais may also belong to this species. It differs in the compound cymes with up to 15 flowers and in the truncate-based sepals but is otherwise similar. Further collections are needed to clarify its status.

Figures

Figure 59. Ipomoea pterocaulis. A habit B mature stem C young stem and leaves D outer sepal E inner sepal F corolla opened up to show stamens G capsule H seed. Drawn by Rosemary Wise A-E, G, H from L. de Queiroz 15957; F from R. Harley et al. 53599.