Monographs Details: Isertia hypoleuca Benth.
Authority: Maguire, Bassett. 1967. The botany of the Guayana Highland--Part VII. Mem. New York Bot. Gard. 17: 1-439.
Family:Rubiaceae
Scientific Name:Isertia hypoleuca Benth.
Description:Distribution and Ecology - British and French Guiana, Suriname, southern Venezuela, and northern Brazil. FRENCH GUIANA. Godebert, Wachenheim 24. SURINAME. Primary jungle to rear of village of Posoegronoe, Saramacca River headwaters, Maguire 24020. BRITISH GUIANA. Schomburgk 281 (isotype NY); Schomburgk 1044 (photo from B); northeast side of Mount Ayanganna, alt 884-915 m, S. S. & C. L. Tillett 45002; Kako King, S. S. & C. L. Tillett 45444; mixed evergreen forest along Kukui River, S. S. & C. L. Tillett 45396; basin of Essequibo River, lat about 4°40'N, Kurupukari, A. C. Smith 2160; basin of Kuyu-wini River (Essequibo tributary), about 150 m from mouth, A. C. Smith 2517; Kurupung Mountains, near Makreba Falls, Upper Mazaruni District, Pinkus 16; Holmia, Potaro River, Bartlett s.n.; Winipero, Persaud 15; bush island on savanna, Kaieteur Plateau, Maguire & Fanshawe 23132. VENEZUELA. Bolivar: vicinity of Arabupu, Mount Roraima District, alt 1515 m, Pinkus 83; Roraima, Schomburgk 674; vicinity of Base Camp, La Escalera, Rio Uiri-yuk, Alto Rio Cuyuni, Maguire, Steyermark & C. K. Maguire 46956; Gran Sabana, northwest base of Uu-tepui, alt 1,000 m, Maguire 33199; exposed rocky slopes of quebrada on southwestern-facing portion of Chimanta-tepui (Torono-tepui), alt 1410 m, Steyermark 75410; forest at summit, north portion of Cerro Uroi, Rio Chicanan, alt 700 m, Maguire, Steyermark & C. K. Maguire 53750; selva de montana, Serrania del Paujil, 120 km sur de El Dorado, alt 1,000 m, Bernardi 6795; Cerro Paujil, Km 92 sur de El Dorado, alt 500 m, Bernardi 2969; cercanias del Rio Chicanan, aproximada lat 6° 13', long 61°53', Baumrucker & Calzadilla 6a; dense forest along Rio Karuai between base of Ptari-tepui and first ridge above Rio Karuai, alt 1220-1375 m, Steyermark 60604; alrededores km 88, carretera El Dorado, Aristeguieta 3742; orillas quebrada Cucurital, Alto Caroni, faldas Auyantepuy, Cardona 2598; a lo largo del Rio Paramichi, nacimiento del Rio Paragua, 10-15 km noroeste de la frontera Venezolano-Brasilera, lat 4°2-3', long 63°3', alt 525 m, Steyermark 90579; selva higrofitica macrotermica algo baja por poca cantidad de suelo, 102 km de El Dorado hacia Santa Elena, Foldats 2867; Rio Karun, Alto Rio Paragua, alt 350 m, Cardona 1232; Playa del Raudal de Guaiquinima, Alto Rio Paragua, alt 300 m, Cardona 871; Amazonas: along Cano Asisa just below Paru savanna camp, Rio Ventuari, alt 200 m, Cowan & Wurdack 31528; forest along trail near Base Camp, Cerro Sipapo (Paraque), alt 125 m, Maguire & Polti 28619. BRAZIL: Para: southern slope of Akarai Mts., in drainage of Rio Mapuera (Trombetas tributary), alt 500-700 m, A. C. Smith 2937; Rio Branco: brush at quebrada head, Ridge No. 1, Serra Tepequem, alt 800—900 m, B. & C. K. Maguire 40051; Amazonas: silva secundaria vetustiore non inundabili, Sao Paulo de Olivenca, Durke 638; mouth of Rio Castanho and Raudales Uayamri, Rio Padauiri, upper Rio Negro basin. Cardona 1253; Grenzexpeditionen General Rondon, Turora, Luetzelburg -22992; Ega, without collector 2509.

Discussion:

Isertia coccinea Vahl var hypoleuca (Benth.) Schum., Mart. FI. Bras. 6(6): 286. 1889.

Type. British Guiana, R. Schomburgk 281.

Specimens of I. hypoleuca are frequently confused with I. verrucosa because the upper portion of the corolla-tube of I. hypoleuca may be verrucose, as in Cardona 1232, but such collections may be distinguished from I. verrucosa by the tomentose ovary, hypanthium, calyx, pedicels, bracts, peduncle, and rachis of inflorescence, broader, more branched inflorescence, dense tomentum on outer surface of corolla-tube, and more abundantly flowered and branched inflorescence, in addition to the 5-6-celled ovary and 5-6 stigmas.

Distribution:French Guiana South America| Suriname South America| Guyana South America| Venezuela South America| Brazil South America|