CONVOLVULACEAE. 351 



5. EXOGONIUM Choisy, Mem. Soc. Phys. Geneve 6: 443. 1833. 



Vines, woody at the base, with alternate leaves and showy, eymose or soli- 

 tary, axillary flower?. Sepals 5, obtuse, somewhat unequal. Corolla salverform 

 or funnelform. Ovary 2-celled; styles united; stigmas globose. Stamens more 

 or less exserted. Fruit a capsule. [Greek, referring to the exserted stamens 

 and styles.] Some 25 species or more, of tropical and subtropical America. 

 Type species: Ipomoea bracteata Cav. 



^ 1. Exogonium microdactylum (Griseb.) House, Bull. Torr. Club 35: 102. 1908. 



Ipomoea microdactylia Griseb. Cat. PI. Cub. 204. 1866. 



Exogonium microdactylum integrifolium House, Bull. Torr. Club 35: 103. 

 1908. 



Glabrous, slightly succulent, the stem sometimes spinulose toward the base, 

 1-3.3 m. long, arising from a large tuber-like root. Leaves various, slender- 

 petioled, 3-10 cm. long, ovate to lanceolate, entire or palmately several-lobed; 

 cymes few-flowered, short-peduneled; pedicels as long as the peduncle or 

 shorter; sepals orbicular-ovate, about 6 mm. long; corolla scarlet to carmine, 

 its slender tube 2.5-4 cm. long, its limb about 2.5 cm. wide, the lobes ovate; 

 capsule subglobose, pointed, 10-12 mm. thick; seeds brown-hairy. 



Pine-lands and scrub-lands, throughout the archipelago from Abaco and Great 

 Bahama to Mariguana and Caicos : Florida ; Cuba. Recorded by Grisebach and by 

 Dolley as Ipomoea arenaria Steud. Salverform Moening-gloet. Catesby 2 : pi. 87. 



6. IPOMOEA L. Sp. PI. 159. 1753. 



Twining trailing or rarely erect herbs, with large showy axillary flowers. 

 Corolla funnelform or campanulate, the limb entire, 5-angled or 5-lobed, the 

 tube plaited. Stamens included. Ovary entire, 2-4-celled, 4-6-ovuled; styles 

 united, included; stigmas 1 or 2, capitate or globose. Capsule usually septi- 

 fragally 2-4-valved, 2-4-seeded. [Greek, worm-like.] About 400 species, of 

 wide distribution. Type species: Ipomoea Pes-tigrinus L. 



Sepals herbaceous, elongated. 

 Sepals long-hirsute. 

 Sepals not long-hirsute. 



Leaves silky-pubescent beneath. 

 Leaves glabrous or nearly so. 

 Sepals short, coriaceous or membranous. 



Stems prostrate or creeping, not twining ; fleshy littoral species. 

 Flowers purple : leaves suborbicular, notched. 

 Flowers creamy-white ; leaves various, oblong to lanceo- 

 late and entire or pinnately lobed. 

 Stems twining, at least their tips. 



Seeds with a coma, or covered with long hairs. 

 Seeds glabrous or pubescent, without a coma. 

 Roots not fleshy and edible. 



Leaves 5 7-parted, the segments toothed or plnnatifid. 

 Leaves entire, sagittate or 3-lobed. 

 Leaves sagittate. 



Leaves cordate, entire or 3-lobed. 

 Corolla 2 cm. long or less. 

 Corolla 5-7 cm. long. 

 Roots fleshy, edible; leaves various. 



1. Ipomoea hederacea Jacq. Icon. Rar. 1: 4, pi. 36. 1786. 



Stem 6-15 dm. long, slender, retrorsely hairy. Leaves ovate-orbicular in 

 outline, long-petioled, deeply 3-lobed, 5-13 cm. long, the lobes ovate, acuminate; 

 peduncles 1 3-flowered, much shorter than the petioles; flowers opening in early 

 morning, soon closing; sepals Lanceolate with long linear often recurved tips, 

 densely hirsute below, sparingly so above, 1.5-2.5 cm. long; corolla funnelform, 



