Ipomoea langsdorffii Choisy in A.P. de Candolle

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

51. Ipomoea langsdorffii Choisy in A.P. de Candolle , Prodr.9: 368. 1845. (Choisy 1845: 368)

Ipomoea elegans Meisn. in Martius et al. , Fl. Brasil. 7: 244. 1869. (Meisner 1869: 244), nom. illeg., non A. Dietrich (1836: 313). Type. BRAZIL. (lectotype J.F.Widgren 309 (BR[00000583768], designated by Wood and Scotland (2017a: 9), isolectotypes S).

Ipomoea patula var. monticola Meisn. in Martius et al. , Fl. Brasil. 7: 240. 1869. (Meisner 1869: 240). Type. BRAZIL. Minas Gerais, Vila Rica, Martius obs. 788 (holotype M[0185028]).

Ipomoea monticola (Meisn.) O'Donell , Lilloa 26: 371. 1953. ( O’Donell 1953a: 371).

Type.

BRAZIL. "Rio de Janeiro", Langsdorff (holotype P03560903 ex Herb. Richard).

Description.

Trailing perennial herb; stems asperous-hirsute, at least 80 cm long. Leaves shortly petiolate, 4-10 × 2-4 cm, broadly oblong, less commonly ovate, apex obtuse and mucronate, base broadly cuneate to rounded, both surfaces roughly pubescent, abaxially whitish; petioles 0.6-1.6 cm, hirsute. Inflorescence of rather compact, pedunculate cymes arising in the axils of leaf-like bracts towards the apex of the stems; bracts resembling small leaves diminishing markedly in size towards the tips; peduncles 0.5-9 cm, sometimes extended to form the rhachis of a racemose inflorescence; bracteoles 12-15 mm, linear, finely acuminate, persistent, hirsute with white or reddish hairs; secondary peduncles c. 5 mm; pedicels 5-12 mm, hirsute; sepals subequal, 12-18 × 4-5 mm, lanceolate to narrowly ovate, densely villous, outer densely brownish villous, inner paler the central hairs brownish, the marginal hairs whitish; corolla 4-5 cm long, white with dark centre, funnel-shaped, pubescent, limb c. 3-3.5 cm diam. Capsules and seeds not seen.

Illustration.

Figure 37 .

Distribution.

Apparently endemic to Minas Gerais State in Brazil, where it grows in cerrado.

BRAZIL. Minas Gerais: P. Clausen s.n. (BM); Bello Horizonte, Villa Cruzeiro do Sul, M. Barreto 2312 (F); Betim, Contagem, Faz. do Cabuí, L.O. Williams 5101 (GH); San Francisco, M. Weddell 1175 (P), 1912 (P); Serra do Itabirito, 45km SW of Belo Horizonte H.S. Irwin et al. 19706 (FTG).

Note.

See Wood and Scotland (2017a) for a discussion of the problematic typification of Ipomoea patula Choisy and its implications. The type location is given as "Rio de Janeiro" but this seems improbable, given that this is a cerrado species, otherwise only known from Minas Gerais.

This species resembles Ipomoea valenzuelensis but the leaves are whitish abaxially and never lobed, and the cymes are usually more than 3-flowered.

Figures

Figure 37. Ipomoea langsdorfii. A, B habit C abaxial leaf surface D peduncle and inflorescence E outer sepal F inner sepal G corolla opened out H ovary and style. Drawn by Rosemary Wise A-C, E-H from Weddell 1912; D from Clausen s. n.