Ipomoea exserta

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

165. Ipomoea exserta J.R.I. Wood & Scotland, Kew. Bull. 50 (31): 82. 2015. (Wood et al. 2015: 82)

Type.

BOLIVIA. Chuquisaca, Prov. Luis Calvo, 14 km E of Monteagudo, on pass before descent to Timboy Pampa J.R.I. Wood 9693 (holotype HSB, isotypes K, LPB).

Description.

Liana to 6 m; stems sometimes pendulous from overhanging branches, woody below, somewhat wiry above, thinly pilose, glabrescent when old, sometimes leafless when flowering. Leaves petiolate, 6-14 × 5-10 cm, mostly ovate, sometimes suborbicular, occasionally shallowly 3-lobed or with a single lateral tooth, base cordate to subtruncate with rounded auricles, apex acute, margin entire to obscurely undulate, adaxially dark green, appressed pubescent with long hairs, abaxially grey-matted-tomentose with some stellate hairs mixed with unbranched hairs; petiole relatively short, 3-4 cm, pilose. Inflorescence of compact many-flowered, axillary cymes, often subracemose in form; peduncle 5-11 cm, commonly twisted, shortly pilose; bracteoles oblong, caducous; secondary peduncles 6-10 mm, glabrous; pedicels 2-10 mm, glabrous; sepals subequal, 9-11 × 4-6 mm obovate-elliptic, coriaceous, convex, glabrous, margins narrow, scarious; outer sepals minutely mucronate; inner sepals slightly wider than the outer, rounded; corolla 5-5.8 cm long, completely glabrous, hypocrateriform, the basal subcylindrical tube 3.5-3.8 × 0.5-0.9 cm, brownish, the limb 1.5-2 cm long, spreading, lobed, dark pink; stamens and style exserted 5-8 mm. Capsules and seeds not seen.

Illustration.

Figure 96 .

Distribution.

Endemic to Bolivia in Bosque Serrano Chaqueño between 400 and 1400 m. from the Santa Cruz area south to the Villamontes area.

BOLIVIA. Chuquisaca: Boeto, Pampa del Tigre, J.R.I. Wood et al. 20543 (K, LPB); Luis Calvo, Monteagudo-Timboy Pampa, J. Gutiérrez et al. 320 (MO, USZ); Incahuasi, J.R.I. Wood et al. 27643 (K, LPB, USZ); Siles, Río Azero, J.R.I. Wood 13308 (K, LPB). Santa Cruz: Cordillera, Tatarenda, J.R.I. Wood et al. 16093 (K, LPB, USZ); Florida, Bella Vista, L. Arroyo et al. 2868 (USZ); Ibáñez, La Angostura, M. Mendoza & Eduardo 987 (K, USZ). Tarija: Gran Chaco, Río Pilcomayo gorge, J.R.I. Wood et al. 27595 (K, LPB, USZ); O’Connor, Palos Blancos towards Entre Ríos, J.R.I. Wood et al. 28042 (LPB, OXF, USZ).

Notes.

Similar to Ipomoea oranensis but immediately distinguished by the hypocratiform corolla with a cylindrical tube and exserted genitalia.

Both Ipomoea exserta and I. oranensis have some stellate hairs mixed with unbranched hairs but these are often difficult to see. The two species may sometimes grow together but I. oranensis is found most commonly at higher altitudes, from 1600 to 2200 m, although there are a few records from as low as 650 m.

Figures

Figure 96. Ipomoea exserta. A habit B adaxial leaf surface C abaxial leaf surface D outer sepal E inner sepal F corolla opened out to show stamens G ovary and style. Drawn by Rosemary Wise from Wood 16093.