Monographs Details: Platycarpum orinocense var. orinocense
Authority: Maguire, Bassett & Wurdack, John J. 1964. The botany of the Guayana Highland--Part V. Mem. New York Bot. Gard. 10: 1-278.
Family:Rubiaceae
Description:Distribution and Ecology - Additional specimens examined: VENEZUELA. Amazonas: occasional in scrub forest bordering crystalline laja, Puerto Ayacucho; alt. 100-120 m; tree to 15 m; flowers 5-merous, slightly zygomorphic; pubescence tawny; corolla lobes white apically, red basally, the lowermost segment with yellow bearding; 8 Nov 1953, Maguire, Wurdack, c& Bunting 36063 (NY) ; Cerro Moriche, Rio Ventuari; tree 10 m; stipules early caducous, 5-10 cm long; flowers irregular, 4-5-merous; sepals white; 2-3 petals white with basal red streaks; 1-2 petals white with basal yellow streaks; 13 Jan 1951, Maguire, Cowan, d: Wurdack 30850 (NY); Cerro Moriche, Rio Ventuari; 14 Jan 1951, Maguire, Cowan, & Wurdack 30877 (NY) ; Cerro Yutaje, Rio Manapiare; dominant tree of savanna 1 km east of Base Camp; alt. 150 m; tree to 20 m high X 2 dm diam; 30 Jan 1953, B. & C. K. Maguire 35046 (NY); occasional around rock outcrops at Sanariapo; 24 Apr 1953, Maguire & Wurdack 35736 (NY) ; Sabana Huachapana; 15 Sep 1957, Maguire, Wurdack, & Keith 41463 (NY); Savanna Huachapana, 30 km above Santa Barbara; 18 Jan 1958, B. & C. K. Maguire, Wurdack, d' Keith 42655 (NY); Puerto Ayacucho, Mar 1950, Curran 1789 (VEN); bords de I'Orenoque, 1887, Gaillard 204 (photo of topotype from P at F) ; savanna hills southeast Guanay; 27 Jan 1951, Maguire, Cowan, & Wurdack 31617 (NY).

Discussion:

The following details may be added to the description previously published in Am. Jour. Bot. 39 : 421-22. 1952:

Stipule at very summit of leafy branch (good one seen on specimen of Maguire & Maguire 35046 from Cerro Yutaje), linear-lanceolate, obtuse at apex, (5-)8-8.5(-10) cm long, 1.3-1.5 cm wide, tawny densely sericeous, densely buff-stramineous sericeous within, villous without, other stipules caducous; mature capsule 3.5-4 cm broad; seed sublunar-oblong, convex on one edge, subtruncate on other, 3.5 cm long, 1.7-2 cm high, the body chestnut or rufousbrown, the body proper 1.5-2 cm long, 0.7-1 cm high, wing 6 mm broad with a blackish band 1.5-2 mm broad bordering edge and 1.5-2 mm from edge.

The specimen of Maguire, Cowan, d' Wurdack 30877 has some of the flowers with four calyx-lobes, but most of them have five calyx-lobes. Other variations noted in flowering material are found in the specimens of Maguire, Wurdack, & Bunting 36063 taken near the type locality of Puerto Ayacucho. This collection has smaller flowers than average, 17-19 mm long with lobes 7-10 mm long and 5.5-6 mm wide, but also shows large flowers up to 24 mm long with corolla-lobes 8-10 mm long and 6-9 m m wide. In this collection the calyx-lobes vary from 5 to 6 on the same inflorescence with variability from 3 to 1 m m wide on the same flower and from 8-8.5 mm long to 9 mm long and 7 m m wide.

A marked variation of Platycarpum orinocense from the base of Cerro Paru is herewith described:

Distribution:Venezuela South America|