Ipomoea spinulifera

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

46. Ipomoea spinulifera J.R.I. Wood & Scotland, Kew Bull. 50 (31): 47. 2015. (Wood et al. 2015: 47)

Type.

BOLIVIA. Tarija, Prov. O’Connor, on descent from Caneletas to Narvaéz, on road from Tarija to Entre Ríos, J.R.I. Wood 27923 (holotype LPB, isotypes K, LPB).

Description.

Very vigorous liana-like perennial to 5 m; stems relatively stout, thinly pilose with long white hairs, spinulose with short triangular spines on angles. Leaves petiolate, 9-11 × 8-10 cm, ovate, base cordate with rounded auricles, apex acute to shortly mucronate, margin entire, adaxially green, glabrous, abaxially paler, veins pilose and highlighted with whitish hairs, intercostal regions glabrous; petioles 5-9 cm, thinly pilose. Inflorescence of long-pedunculate, lax, compound cymes comprising 5-10 flowers; primary peduncles very long, 17-21 cm, thinly pilose and with a few scattered stalked glands and spinules; secondary peduncles 3-3.5 cm, pilose; tertiary peduncles 2-3 cm; bracteoles 1.5 × 0.5 mm, oblong, caducous; pedicels 12-23 mm, densely white-pilose, bearded below flower; outer sepals 10-11 × 7 mm, ovate, obtuse to retuse, dark green when fresh, pubescent at centre near base, glabrous upwards and at margins, the scarious margins thin; inner sepals 10-11 × 8 mm, broadly elliptic, glabrous except near base, scarious margins broad; corolla 7.5-9 cm long, gradually widened from base, pink, in bud pubescent, limb c. 5 cm diam., undulate to weakly lobed. Capsules and seeds not seen.

Illustration.

Figure 33 .

Distribution.

Endemic to the Andes in Tarija Department, Bolivia, where it is locally common between 1600 and 2100 m in scrub and forest relics derived from former moist Tucuman-Bolivian forest.

BOLIVIA. Tarija: Arce, M. Serrano et al. 6038 (ARIZ, MO); O’Connor, J. Villalobos et al. 1307 (OXF, HSB, MO); J.R.I. Wood et al. 28047 (LPB, USZ).

Notes.

Ipomoea spinulifera appears to be related to I. hieronymi but is distinguished by the dark green, near glabrous sepals, very large corolla 7.5-9 cm long and spinulose stems.

M.A. Negritto et al. 502 (MA, CORD, n.v.) from an unspecified location in Prov. Arce in Tarija Department appears to be intermediate between this species and Ipomoea jujuyensis . It was identified by the collectors as I. lilloana to which it would key following O’Donell’s (1959b) key to Argentinian species of Ipomoea because of the pubescent midpetaline bands which are clearly visible on the buds but it is not I. lilloana , which is a trailing plant with distinct undulate leaves. The somewhat truncate calyx and large corolla suggests an affinity with I. spinulifera but the leaves are very different.

Figures

Figure 33. Ipomoea spinulifera. A habit B section of stem showing spinules C adaxial leaf surface D abaxial leaf surface E outer sepal F inner sepal G corolla opened out to show stamens H ovary and style. Drawn by Rosemary Wise A, B from Villalobos et al. 1307; C-H from Wood 27923.