GLEASON: CENTROPOGON AND SIPHOCAMPYLUS 197 
20. SIPHOCAMPYLUS GRACILIs Britton, Bull. Torrey Club 19: 374. 
1892. 
Siphocamplyus corymbiferus gracilis A. Zahlb. Bull. Torrey 
Club 24: 384. 1897. 
Leaves softly pubescent. 
iii. Flowers in crowded leafy racemes. 
. SIPHOCAMPYLOS TUPAEFORMIS A. Zahlb. Ann. K. K. Natur- 
hist. Hofmus. Wien 6: 440. 1891. 
Hypanthium hemispheric or Pages urceolate, ribless or 
faintly nerved; flowers 40-45 mm. long, approximately equaling 
the ascending, straight or gently curved pedicels; leaves softly 
pubescent beneath. 
b. Anther-tube conspicuously woolly in five strongly marked lines; leaf-blades lanceo- 
late or broader, rounded at nest es much longer than the hypanthium, 
which is strongly ribbed at ma 
* Leaf-blades long-acuminate, ovate-lanceolate to lance-oblong, sharply and 
irregularly spinulose-denticulate. 
22. SIPHOCAMPYLUS ARGUTUS A. Zahlb. Bull. Torrey Club 24: 
383. 1897. 
Leaf-blades thin, glabrous Scocath: not prominently reticulate; 
petioles straight or curved. 
23. SIPHOCAMPYLUS BILABIATUS A. Zahlb. Bull. Torrey Club 
24: 382. 1897. : 
Siphocampylus bilabiatus glabratus Lauterbach; Buchtien, 
Contr. Flora Bolivia 1: 187. 1910. 
Leaf-blades firm, pubescent beneath, prominently reticulate; 
petioles sigmoid. - 
** Leaf-blades ovate-oblong, 5-8 cm. long, broadly rounded or subcordaté at 
base, obtuse or rounded at apex, minutely and remotely denticulate. 
24. SIPHOCAMPYLUS SUBCORDATUS Rusby, Bull. N. Y. Bot. 
Gard. 8: 121. 1912. 
2. Flowers in terminal, leafless, bracted racemes; pedicels flexuous in anthesis, 1 cm 
long or less; hypanthium turbinate, strongly ribbed or subangulate, somewhat 
constricted at the throat, equaling or exceeding the relatively short sepals; 
-sinuses 
broad. 
ypanthium glabrous; leaf-blades falcate, conduplicate. - 
