Ipomoea angustissima

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

17. Ipomoea angustissima J.R.I. Wood & Scotland, Kew Bull. 72 (9): 13. 2017. (2017a: 13)

Type.

BRAZIL. Goiás, 16 km N of Alto Paraíso Gates & Estabrook 106 (holotype RB223038, isotype FTG).

Description.

Perennial herb to 40 cm from a tuberous rootstock, apparently unbranched or branched near the base only; stems erect, asperous-pubescent. Leaves sessile or very shortly petiolate, 1-7 segments radiating out from the base, segments 0.8-5 × c.0.1 cm linear, acute, 1-veined, thinly pilose to ± glabrous; petioles 0-2 mm, thinly pilose. Inflorescence terminal consisting of single flowers or compact few-flowered cymes from the uppermost leaf axils; peduncles 1-9 mm, pubescent; bracteoles 3 × 1.5-2 mm, oblong, rounded to retuse, thinly pubescent, margin scarious, caducous; pedicels 3-7 mm, pubescent; sepals subequal, 5-8 × 5-6 mm, elliptic, obtuse to rounded, pubescent except for the scarious margins, outer sometimes mucronulate, reddish, margins narrow, inner more rounded with broader scarious margins; corolla 3.5-4 cm long, funnel-shaped, pink, pubescent, limb c. 2.5 cm diam., somewhat lobed. Capsules and seeds not seen.

Illustration.

Figure 20 .

Distribution.

Campo húmedo at relatively high altitudes in the Chapada dos Veadeiros. BRAZIL. Goiás: Alto de Paraíso area, H.S. Irwin et al. 32976 (MO, NY); ibid., Gates & Estabrook 106 (FAU, RB223038); ibid., J.R. Pirani et al. 1765 (K, SPF); c. 65 km due N of Brasilia, R.M. Harley et al. 11361 (K); ibid., M.J. Graziela & A. Lima 829-68 (IPA, OXF); Mun. Cavalcante, frente entrada a Faz. Vicente, J.F.B. Pastore et al. 816 (CEN).

Note.

This species is often identified as Ipomoea fiebrigii in error but is immediately distinguished by the terminal inflorescence, shorter, rounded or obtuse sepals and the absence of long white hairs on the inner sepals and corolla. It is also sometimes identified as Ipomoea stenophylla (= I. campestris ) but differs in the terminal inflorescence and elliptic, rounded, not acute sepals. The upper part of stem and peduncles appear to be sticky as granules of sand stick to the hairs, the stem appearing superficially to be granulose.

J.R. Pirani et al. 1765 differs from other specimens in having some entire, lanceolate or ovate, ± obtuse leaves 1.5-3.5 × 0.3-0.8 cm. R. Romero et al. 4796 (SP) from P.N. Serra de Canastra, São Roque de Minas, Minas Gerais might also belong to this species but the inflorescence is axillary and is only known to us from an image.

Figures

Figure 20. Ipomoea angustissima. A habit B stem showing leaves C outer sepal D middle sepal E inner sepal F corolla opened out G ovary and style. Drawn by Rosemary Wise A from Harley et al. 11361; B from Gates & Esterbrook 106; C-G from Irwin et al. 12542.