A foundation monograph of Ipomoea (Convolvulaceae) in the New World Author Wood, John R. I. Author Munoz-Rodriguez, Pablo Author Williams, Bethany R. M. Author Scotland, Robert W. text PhytoKeys 2020 143 1 823 http://dx.doi.org/10.3897/phytokeys.143.32821 journal article http://dx.doi.org/10.3897/phytokeys.143.32821 1314-2003-143-1 F6F11A6EE4FF5A1885CEA2B60AE965A5 172. Ipomoea discolor (Kunth) G. Don , Gen. Hist. 4 : 270. 1838. (Don 1838: 270) Convolvulus discolor Kunth , Nov. Gen. Sp. 3 : 105 (1818 [pub. 1819]. (Kunth 1819: 105), nom. cons . Type. VENEZUELA. Amazonas, Carichana, Humboldt & Bonpland 1045 (holotype P00670759). Ipomoea irengana N.E. Br., Trans. Linn. Soc. London, Bot. ser. 2, 6: 51. 1901. (Brown, NE 1901: 51). Type. GUYANA. Ireng Valley, McConnell & Quelch, 265 (lectotype K000612822, designated here). Type. Based on Convolvulus discolor Kunth Description. Slender twining herb, stems pubescent. Leaves petiolate, very small, 1.2-4 x 1.2-2.3 cm, ovate, obtuse and mucronate, shallowly cordate with rounded auricles, adaxially green, tomentellous, abaxially white-canescent. Flowers solitary, axillary; peduncles 4-25 mm, pubescent; bracteoles filiform, c. 1 mm, caducous; pedicels 6-15 mm, pubescent; sepals subequal, 7-11 mm long, oblong-lanceolate, acute or obtuse, outer pubescent, inner glabrous, scarious, more rounded; corolla 3.5-5.5 cm long, pale pink, funnel-shaped, thinly pubescent, limb undulate, 3.5-4 cm diam. Illustration. Austin (1998: 399). Distribution. Dry rocky hills at low altitudes in Venezuela and Guyana; apparently uncommon. GUYANA. Type of Ipomoea irengana . VENEZUELA. Bolivar : Cedeno District, B. Boom & Grillo 6399 (FTG, NY); Cerro Gavilan, J. Wurdack & J.V. Monachino 40901 (FTG, NY); Agua Amena, J. Steyermark et al. 131440 (FTG, MO); 1 km S of Quebrada la Flore, J. Steyermark et al. 131637 (FTG). Lara : between Quibor and Cubiro, D.F. & S. Austin 6019 (FTG). Note. This species is anomalous in this clade because of the thinly pubescent corolla.