102 House: North American Convolvulaceae 



8. Exogonium argentifolium (A. Rich.) 

 Ipomoeaf argentifolia A. Rich, in Sagra, Hist. Fis. Cuba ii : 131. 



1850. 

 Ipomoea praecox Wright [in Sauv. Fl. Cub. 107] Anal. Acad. 



Habana 7 : 46. 1870. 



A stout twining vine : stems tomentose above : leaf-blades 

 oblong-lanceolate to elliptical-oblong, acute or rounded at the 

 base, the apex acute or obtuse, 2-10 cm. long, woolly above, 

 becoming glabrate : sepals suborbicular, obtuse, 5-6 mm. long, 

 woolly or tomentose without, equal : corolla salverform, the tube 

 6-7 mm. in diameter ; the limb 3 cm. broad. 



Type locality: " Prope Nouvelle Sophie," Isle of Pines. 



Distribution : Cuba, Isle of Pines, and southern Mexico. 



Specimens examined : Cuba, C. Wright 4.^^, 3646 ; Cook 

 1905. Isle of Pines, Ctirtiss 48 g, 1904, Rowlec 182, 1901. 

 Mexico: Oaxaca, Conzatti & Gonzalez JJ2, 1894, Pringle 5636, 

 1894; Puebla, E. IV. Nelson 20og, 1895, Pringle 7016, 1895. 



9. Exogonium Conzattii (Greenm.) 

 Ipomoea Conzattii Greenm. Field. Col. Mus. Publ. Bot. 2 : 258. 

 1907. 



Resembling the preceding : leaf-blades not seen : flowers in 

 dense, many-flowered, subsessile clusters ; pedicels and peduncles 

 tomentose : sepals slightly unequal, broadly ovate, obtuse, tinged 

 with red : corolla-tube 3 cm. long, the scarlet limb 2 cm. broad, 

 pubescent without: capsules 10-12 mm. in diameter, 2-celled ; 

 coma of hairs on the seeds white. 



Type locality : Almoloyas, Guerrero, Mexico. 



Distribution: Southern Mexico. 



Specimens examined: Guerrero, E. IV. Nelson 2og§, 1894 

 (in herb. Gray and Nat. Herb.). (The type, Conzatti 1666, 1906, 

 in herb. Field Mus., not seen.) 



10. Exogonium microdactylum (Griseb.) 

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



A glabrous twining vine : stems woody below, striated or 

 muricate : leaf-blades 3-5-lobed or subentire, 3-6 cm. long, thick- 

 textured, lobes usually oblanceolate, obtuse, reticulate-veined : 

 peduncles 1-3-flowered : sepals unequal, orbicular-ovate, obtuse, 

 5-7 mm. long : corolla scarlet, subsalverform, 3-4 cm. long, the 

 limb 3-5 cm. broad and slightly 5-lobed: capsules 10 mm. in 

 diameter, ovoid, apiculate. 



