Ipomoea revoluta

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

18. Ipomoea revoluta J.R.I. Wood & Scotland, Phytokeys 88: 25. 2017. (Wood et al. 2017d: 25)

Type.

BRAZIL. Mato Grosso do Sul, Serra de Maracaju, 17 Feb. 1970, G. Hatschbach 23761 (holotype MBM, isotypes CTES, F, MICH, S).

Description.

Slender twining liana of unknown height; stem woody, c. 2-3 mm thick, pale brown, shortly pubescent. Leaves petiolate, digitately divided into 5-7 free leaflets; leaflets 5-9 × 0.15-0.4 cm, linear, attenuate to a mucronate apex, basally tapered, margin inrolled; adaxally glabrous, midvein strongly impressed; abaxially white-tomentose, the midvein prominent, nearly glabrous; petioles 8-13 mm, thinly pubescent;. Inflorescence of 1-3-flowered axillary cymes; peduncles 7-9 mm, very thinly pubescent with scattered hairs; bracteoles c. 1 mm long, scale-like, caducous; pedicels 8-10 mm long, very thinly pubescent with scattered hairs; sepals subequal, 8-10 × 6-7 mm, ovate to elliptic, acute to shortly mucronate, sericeous with narrow, scarious, glabrous margins, inner sepals white-sericeous with wider scarious margins; corolla 5-6 cm long, pink, sericeous in bud, funnel-shaped from a short basal cylindrical tube, limb c. 2 cm diam., lobes rounded. Capsules ovoid, apiculate, c. 10 mm long (immature), glabrous, ± enclosed by the sepals; seeds not known.

Illustration.

Figure 21 .

Distribution.

Apparently endemic to the Serra de Maracaju in Mato Grosso do Sul, where it grows on sandstone rock outcrops.

BRAZIL. Mato Grosso do Sul: G. & M. Hatschbach & J.M. Silva 60724 (MBM).

Note.

This species is almost certainly related to Ipomoea malvaeoides and its allies but is distinguished from all of these by its twining (not erect) habit and distinctly petiolate leaves. Related species in which the leaves have linear leaflets, such as I. fiebrigii , I. itapuaensis and I. theodori , have sessile or near sessile leaves. The linear leaflets recall those of the unrelated Ipomoea subrevoluta , which it has been wrongly named in many herbaria. It is easily distinguished from that species by the sericeous exterior of the corolla and the large, abaxially pubescent sepals.

Figures

Figure 21. Ipomoea revoluta. A habit B adaxial leaf surface C abaxial leaf surface D inflorescence E Outer sepal F middle sepal G inner sepal H corolla opened out to show stamens J calyx enclosing capsule. Drawn by Rosemary Wise from G. Hatschbach 23761.