Ipomoea lactifera

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

223. Ipomoea lactifera J.R.I. Wood & Scotland, Kew Bull. 70 (31): 91. 2015. (Wood et al. 2015: 91)

Type.

BOLIVIA. Santa Cruz, Prov. Ichilo, 2-20 km from Buenavista along road to El Huaytú, J.R.I. Wood & D. Soto 27954 (holotype USZ, isotypes OXF, K, LPB).

Description.

Perennial twining herb of unknown height, latex white, stem glabrous. Leaves petiolate, 5-9 × 3.3-7 cm, ovate, base cordate and very broadly cuneate onto the petioles, auricles rounded, apex acuminate to a shortly mucronate apex, margin entire, glabrous except for an area of puberulence on veins and margin at base around point of insertion of petiole; petiole 2.2-6.8 cm, glabrous but thinly puberulent upwards. Inflorescence of long pedunculate, many-flowered, axillary cymes; peduncles 5-10 cm, glabrous, secondary peduncles 1.5-3 cm; bracteoles 1 × 1 mm, suborbicular, early caducous leaving a prominent basal scar; pedicels 8-14 mm, glabrous to slightly farinose; sepals glabrous or somewhat farinose, unequal, somewhat papery in texture, the margins slightly scarious but not conspicuously pale, outer 5-6.5 × 2.5-3 mm, oblong-obovate, rounded, the central vein prominent, slightly raised and terminating in a mucro, inner 7-8.5 × 5 mm, elliptic, rounded, minutely mucronulate with the mucro deciduous; corolla 3-4 cm long, broadly funnel-shaped and gradually widened from base, limb 2-2.5 cm diam., white or very pale pink with darker centre, glabrous; ovary glabrous. Capsules and seeds not seen.

Illustration.

Figure 114 .

Distribution.

Endemic to humid forest or forest relics in the Andean foothills of Bolivia and Ecuador between 200 and 1000 m.

BOLIVIA. Beni: Ballivián, upstream from Rurrenabague, D.C. Daly et al. 6639 (FTG); Est. Biologica del Beni, G. Caity 149 (K, LPB, OXF); Cercado, F. de la Puente 3593 (CIP). Cochabamba: Chapare, El Choclotal, J.R.I. Wood 23411 (K, LPB, USZ); P.N. Carrasco, Yanamayo, M. Zarate 6455 (BOLV, LPB). Santa Cruz: Ichilo, P.N. Amboró, opposite El Huaytú, J.C. Solomon 14004 (K, LPB, MO).

ECUADOR. Morona-Santiago: Centro Shuar Yukatais, Chacras, B. Bennett & P. Gómez A 3783 (OXF,?NY, QCNE).

Note.

The discovery of Ipomoea lactifera is of exceptional interest as it is an additional crop wild relative of the sweet potato. Apart from I. batatas itself it is the only perennial species of this group growing in Bolivia and the first with an exclusively Andean distribution. From other species in this clade it can be distinguished by its large white or pale pink corolla and relatively broad obovate to elliptic sepals.

Figures

Figure 114. Ipomoea lactifera. A habit B outer sepal C middle sepal D inner sepal E corolla opened out to show stamens F ovary and style. Drawn by Rosemary Wise from Solomon 14004.