Ipomoea magna Sim.

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

104. Ipomoea magna Sim. -Bianch & J.R.I. Wood. Kew Bull. 72 (8): 18. 2017. (Wood et al. 2017a: 18)

Type.

BRAZIL. Minas Gerais, 13 km W of Januária on road to Serra das Araras, 575 m, 19 April 1973, W.R. Anderson, P. A. Fryxell, S.R. Hill, R. Reis dos Santos & R. Souza 9184 (holotype UB, isotypes FTG, NY).

Description.

Liana reaching at least 10 m, stems twining, woody, tomentose, latex white. Leaves petiolate, 8-28 × 7-22 cm, ovate, cordate with rounded auricles, apex acute or obtuse and shortly mucronate, margin slightly undulate, adaxially green, roughly tomentellous, abaxially grey-tomentose with highlighted veins; petioles 5-11 cm, tomentose. Inflorescence of axillary cymes wth up to seven flowers; peduncles 2.5-10 cm, tomentose; bracteoles (8-)12-18 × 4-7, oblong or oblong-obovate, obtuse, glabrous, caducous; secondary peduncles 4-23 mm, thinly pubescent; pedicels 10-30 mm, thickened upwards, glabrous; sepals subequal, 12-19 × 9-12 mm, accrescent in fruit to 25 × 14 mm, elliptic to obovate, rounded, glabrous on the exterior but scurfy-pubescent on the interior, inner with narrow scarious margins, slightly larger; corolla 8-12 cm long, funnel-shaped, pale pink on exterior, darker inside tube, glabrous, limb 6-8 cm diam.; anthers and style included. Capsules c. 21 × 12 mm, ellipsoid, glabrous; seeds 12 × 6 mm, pilose on angles with long white hairs up to 20 mm in length.

Illustration.

Figure 69 .

Distribution.

Centred on Bahia State, Brazil this species is widespread on the borders of scrub and woodland at the transition from the cerrado to caatinga biomes. There is a smaller disjunct population on the borders of Paraguay and Mato Grosso do Sul state.

PARAGUAY. Amambay: P.N. Cerro Corá, J. Fernández Casas & J. Molero 6141 (MA, G, MO); ibid., W. Hahn 1746 (MO, PY); NE of park headquarters, J.C. Solomon et al. 7082 (MO, PY); Cerro Sarambí, 20 km from P.N. Cerro Corá, S. Keel & L. Spinzi 1833 (FCQ). Concepción: 20 km N of Ybyau, N. Soria 5176 (FCQ).

BRAZIL. Bahia: Faz. de Cova, E. Pereira & G. Pabat 8566 (F); Mun. Maracás, 13-15 km SW of Maracas, S. A. Mori et al. 9985 (MO, NY); Reandi, 15-19 km, estrada Urandi-Licinio de Almeida, T. Jost et al. 508 (IPA); Mun. Caetité, camino da Faz. Boa Vista para Urânio, E. Saar et al. 5254 (ALCB, K). Ceará: Serra de Ararifé, Gardner 2030 (BM). Goiás: Serra Dourada, 6 km NE of Mossamedes, W.R. Anderson 10183 (FTG, NY). Mato Grosso do Sul: Mun. Bonito, G. Hatschbach et al. 74730 (MBM). Minas Gerais: 13 km W of Januária on road to Serra das Araras, W.R. Anderson 9184 (FTG, NY, UB); Cabeceira Grande, G. Pereira-Silva et al. 6398 (CEN).

Notes.

Resembling a giant form of Ipomoea brasiliana but immediately distinguished by the long hairs on the seeds as well as the larger dimensions of the leaves, sepals and corolla. It appears to be closely related to I. longibracteolata but is distinguished by the absence of long white hairs on the inflorescence, the laxer cymes and different-shaped corolla.

The populations from Paraguay and neighbouring Mato Grosso do Sul are poorly known but seem indistinguishable from the larger populations further north in Brazil.

Figures

Figure 69. Ipomoea magna. A habit B adaxial leaf surface C abaxial leaf surface D outer sepal E inner sepal F calyx in fruit G seed. Drawn by Rosemary Wise A, F, G from W. R. Anderson et al. 10183; B, C from S. A. Mori et al.; D, E from T. Jost et al. 508.