Windsorina, a new genus of Rapateaceae 
HENRY ALLAN GLEASON 
(WITH PLATE 7) 
The small family Rapateaceae is still one of the most 
poorly known groups of South American plants. Seubert knew 
but three genera and six species when he monographed the group 
for the Flora Brasiliensis in 1847. At approximately the same 
period the Schomburgk brothers were exploring British Guiana 
actively and brought out other remarkable species from the 
dense forests of that region, and Spruce contributed still other 
novelties from northern Brazil and southern Venezuela. K6r- 
nicke summarized the existing knowledge of the family in 1873, 
and his treatment remains the latest monograph. The greatly 
condensed discussion given the family by Engler in 1888 indicates 
that it was still scantily represented in continental herbaria, 
although Bentham and Hooker seem to have had fairly abundant ; 
material at hand when they published Genera Plantarum in 
1883. It is still poorly illustrated in American herbaria, be- 
cause of lack of recent exploration in the hinterland of the 
Guianas and Brazil, although the recent collections of Hitch- 
cock, Gleason, and De La Cruz have included several of the 
coastal species. 
The characters and history of the family were published in 
detail by Kérnicke and need no re-statement. The distinction 
of genera lies chiefly in the structure of the anthers and the 
nature of the inflorescence. The latter is invariably a head or 
a headlike umbel, is usually subtended by an involucre of one 
or two foliaceous bracts, and is borne on a long peduncle arising 
from the base of a leaf and protruding from within the leaf- 
sheath. 
On June 27, 1921, the writer was walking through the six 
miles of dense tropical forest between Kangaruma and Potaro 
Landing, on the Potaro River, British Guiana. His attention 
was attracted by a gregarious plant with broadly linear leaves, 
growing in a small marsh along the trail and apparently sterile. 
Closer examination showed that each plant bore numerous long 
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