Roraima in southern Venezuela. Both are highly adapted 
to xerophytic conditions, having thick, coriaceous leaves. 
Graffenrieda fantastica is further adapted to xerophytic 
conditions by having the young and crassulent branch- 
lets tightly covered with a chartaceous and apparently 
impervious bark which, when broken, easily peels from 
the stem. 
Graffenrieda fantastica is one of the dominant shrubs 
on the long, flat sterile sandstone summit of Mount Chi- 
ribiquete where it forms dense stands of at least one 
thousand per hektar, intermingled with Hevea nitida 
var. towicodendroides Ficus chiribiquetensis, Plumeria sp., 
Bombax coriaceum, Roupala saxicola, Gongylolepis ma- 
roana and Senefeldera chiribiquetensis. The collection 
Schultes 5620 was formerly identified and reported (in 
Caldasia 8 (1944) 121-130; in Chron. Bot. 9 (1945) 123- 
127), as representing Miconia paradowa Triana, a vege- 
tatively very similar xerophyte from the nearby sand- 
stone hills of Araracuara. 
Cotompia: Comisaria del Vaupés, Upper Apaporis Basin, Rio Ma- 
caya, Cerro Chiribiquete, alt. about 1200 ft. above forest floor or 2100 
ft. above sea-level. ‘‘On sterile sandstone top of mountain. Leaves 
fleshy. Flowers white, very fragrant. Bush up to 12 ft., very scrag- 
gly. Bark basally rugose, grey; terminally glossy, red-brown.’’ July 
24, 1943, Richard Evans Schultes 5620 (Tyrer in Herb, Gray; Dupti- 
cate Types in U.S. Nat. Herb., Herb. Nac. Colomb.).—Same locality. 
“*“Seraggly bush, 8-10 ft. tall.’’ May 15-16, 1943, Richard Evans 
Schultes 5467. 
GENTIANACEAE 
Chelonanthus chelonoides (L.f.) Gilg in Engler 
et Prantl. Pflanzenfam. 4, Abt. 2 (1895) 98. 
This heliophile is sometimes found in extraordinary 
abundance on the open savannas of the sandstone moun- 
tains of the upper Apaporis basin. 
[ 307 | 
