brous on both surfaces; peduncles usually one per plant, 
7-14 cm. long, very slender, stramineous, 8-costate, gla- 
brous; sheath slender, closely appressed, 2—2.5 cm. long, 
glabrous throughout, split at the apex, the blade about 
5 mm. long, erect or the tip very slightly spreading, 
subulate-tipped, glabrous; heads small, hemispheric, 
white, 83-5 mm. wide; involucral bractlets broadly obo- 
vate, thick-textured, stramineous, closely appressed and 
imbricate, about 1.6 mm. long and wide, shiny, rounded 
at the apex, glabrous; receptacular bractlets similar but 
appressed, white-pilose on the back and shortly white- 
barbate towards and at the apex with stiffly erect hairs; 
staminate florets: sepals 3, connate at the base, cuneate- 
spathulate, about 0.8 mm. long and 0.4 mm. wide, 
rounded and white-barbate at the apex with stiffly erect 
hairs; petals 8, connate into a slender stramineous tube 
about 0.8 mm. long, the free tips densely white-barbate 
like the sepals; stamens 6; filaments very short, about 
0.16 mm. long, glabrous; anthers oblong, dark-brown, 
about 0.2 mm. long and 0.12 mm. wide; pistillate florets 
not seen. 
Since the type locality of Hriocaulon vaupesense lies on 
the boundary between Colombia and Venezuela, this 
species probably occurs also in Venezuela. 
Cotomsra: Comisaria del Vaupés, Rio Guainia, Cafio del Caribe (be- 
tween Isla del Venado and San José) and vicinity. Altitude 850-900 
feet. Lat. 2°45’ N, Long. 67°50’ W. November 2, 1952. Richard 
Evans Schultes, Richard E. D, Baker & Isidoro Cabrera 18274 (Tyre in 
U.S. Nat. Herb.). 
ARISTOLOCHIACEAE 
Aristolochia georgica R. 17. Schultes sp. nov. 
KFrutex scandens, gracilis. Caulis volubilis; rami vol- 
ubilis, teretes, striolati, cum cortice fusco-brunneo, tenui, 
minutissime puberulente. Folia exstipulata, coriacea vel 
firme chartacea, oblonga, apice breviter apiculata, basi 
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