Ipomoea uninervis J.R.I.Wood & Scotland, 2017

Wood, John R. I., Munoz-Rodriguez, Pablo, Degen, Rosa & Scotland, Robert W., 2017, New species of Ipomoea (Convolvulaceae) from South America, PhytoKeys 88, pp. 1-38 : 25-28

Ipomoea uninervis J.R.I.Wood & Scotland sp. nov. Figure 16

Diagnosis.

Ipomoea uninervis can be confused with I. aprica House but differs in the grey-tomentellous, oblong outer sepals 7.5-8 mm long (these are green-tomentose, broadly ovate to suborbicular and 5-6 mm long in I. aprica ) and the elongate inflorescence with deciduous bracts so appearing naked (not leafy with persistent bracts). It is also close to I. oblongifolia (Hassl.) O’Donell but differs in the 1-veined leaves (not with 3-5 prominent longitudinal veins) and oblong, not elliptic bracts, and relatively long inflorescence

Type.

BRAZIL. Distrito Federal, próximo ao posto Colorado, Chácara FTRC, Centro Oeste , 15°41'S, 47°52'W, 6 Feb. 1999, C. Proença, R.S. Oliveira, C.M. Clemente, J.F. Ribeiro 2074 (holotype UB8208-2, isotype E00202955) .

Description.

Perennial undershrub; stems erect, to 1.2 m, sparingly branched, grey-puberulent to subsericeous. Leaves subsessile, 4-12 × 0.1-0.5 cm, linear to narrowly oblong, obtuse, shortly mucronate, both surfaces grey-puberulent to subsericeous, abaxaially paler with a single prominent longitudinal vein; petioles 0-3 mm, tomentellous. Inflorescence of few-flowered cymes from the upper leaf-axils, forming a terminal, usually elongate inflorescence up to 15 cm in length; bracts formed of reduced leaves, caducous so inflorescence appearing naked; peduncles 1-4 mm, grey-tomentellous; bracteoles 1.5 mm, linear, tomentellous, caducous; pedicels 3-7 mm, grey-tomentellous; sepals subequal, 7.5-8 × 3-4 mm, broadly oblong, obtuse to rounded, grey-tomentose, the inner with broad glabrous, scarious margins; corolla 4.5 cm long, pink, pubescent, funnel-shaped; limb c. 4 cm diameter; filaments unequal, shorter 7-10 mm, longer 12-20 mm, glabrous except for basal hairs; anthers 3.5 mm, narrow; ovary bilocular, conical, glabrous; style 15-22 mm, glabrous; stigma bilobed. Capsule and seeds not seen.

Distribution and habitat.

BRAZIL. Endemic to the Distrito Federal and Goiás State, where it appears to be a rare species of cerrado. Figure 5 .

Additional collection seen.

BRAZIL. Goiás: Cristalina, 5 km along estrada para Paracatu, 16°46'S, 47°37'W, 1050 m, J.R. Pirani et al. 1560 (SPF60276, K000944736).

Conservation status.

This species has been found in two quite separate locations and so might be expected elsewhere. However, field notes give no information about its frequency so it should be treated as Data Deficient (DD) within IUCN guidelines until the populations of this species can be carefully evaluated.

Etymology.

The epithet univervis refers to the 1-veined leaves, the principal character separating it from I. oblongifolia .

Note.

Molecular studies using ITS (unpublished data) place this species in a large well-supported clade of around 70 species almost restricted to South America, which is characterised morphologically by the pubescent exterior of the corolla and the subequal, pubescent, ovate herbaceous sepals. The caducous bracts of I. uninervis result in a near naked inflorescence rather different from that of I. aprica with which it is most likely to be confused. It is probably closest to the Paraguay endemic I. oblongifolia from Amambay, but differs most significantly in the 1-veined leaves. I. oblongifolia has prominently 3-5-veined leaves.

Figures

Figure 5. Map of equatorial South America showing the distribution of Ipomoea cuscoensis (●), I. graminifolia (✖), I. uninervis (▲) and I. velutinifolia (■).

Figure 16. Ipomoea uninervis. A habit B abaxial leaf C outer sepal D inner sepal E corolla opened out to show stamens F ovary and base of style. Drawn by Rosemary Wise from C. Proenca et al. 2074.