HOUSE, THE GENUS IPOMCEA 207 



Sepals not tentacular. 



Corolla glabrous, tube 1-1.5 cm. thick. 



Sepals acute or subobtuse; plant more or less 



densely pubescent. 52. I, longipedunculata. 



Sepals long-acuminate, plant sparingly pubes- 

 cent. 53. /. orizabensis. 

 Corolla pubescent without, the tube 1.5-2.5 cm. 

 thick. 



Sepals about 12 mm. long; leaf-blades stri- 



gose-pubescent beneath. 54. 7. tyrianihina. 



Sepals 22-30 mm. long; leaf-blades silvery- 

 pubescent beneath. 55. I. venusta. 



47. Ipomoea iostemma sp. nov. 



Slender, annual, twining, herbaceous, 1-2 m. long or less; stems very slender, 

 sparingly hirsute; leaf-blades ovate and entire to hastate-ovate or 3-lobed, cordate, 

 acuminate, 2-5 cm. long, 1.5-4 cm. wide, pubescent with scattered, inconspicuous 

 hispidulous hairs, lateral lobes acute and short, middle lobe elongated; petioles 

 shorter than the blades; peduncles shorter than the petioles and stouter, usually 

 1-flowered; bracts linear, 8-10 mm. long; sepals linear, 10-12 mm. lon^ and 1-2 mm. 

 broad at the base, the lax tips caudate-acuminate, glabrous; corolla 2-3 cm. long, 

 the violet-purple limb shading into white below. 



Costa Rica: Nicoya, Tonduz 13680, Jan. 1900 (type — Y). Mexico: 

 Ixtapa, Jalisco, E. W. Nelson 414I, 1897 (N). 



i 48. Ipomoea variabilis (Schlecht. & Cham.) Choisy in DC. Prodr. 

 9: 383. 1845. 



Convolvulus variabilis Schlecht. & Cham, in Linnaea 5: 116. 1830. — Hallier f. 

 Bull. Herb. Boiss. 7: 411. 1899. 



A twining annual, glabrous except for the calyx; leaf-blades ovate-lanceolate, 

 acute or acuminate, 5-8 cm. long, entire or usually cordate-hastate, the basal lobes 

 laterally acute; peduncles shorter than the petioles, hirsute at the base, 1-2 cm. 

 long, 3- to 5-flowered; bracts linear-lanceolate; sepals broadly lanceolate or ovate- 

 lanceolate, 12-15 cm. long, hirsute with spreading hairs at the base, glabrous above; 

 corolla blue (or purple), 5-6 cm. long, the limb as broad with 5, rounded lobes; 

 tube white, plicae purple or rose; capsules 8-10 mm. thick; seeds smooth. 



Type locality: Vera Cruz. 

 Distribution : Mexico. 



Specimens examined: Vera Cruz, Mailer 119, 1853 (C, Y). (Hallier, 

 1. c. cites Seler 2532, 3410, from Guatemala.) 



