22 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Panicles narrow and few-flowered; culms 
erect and wiry; blades drying in- 
volute ...--2--. 222s ee eee eee eee eee See TENERA, p. 97. 
Panicles open or contracted, many- 
flowered. 
Panicles 40 to 60 cm. long, the numer- 
ous elongated branches in verticils; 
tropical species..........------- 81. P. megiston. 
Panicles mostly much less than 40 cm. 
long; branches not verticillate. 
Spikelets short-pediceled along the 
nearly simple panicle branches.See AGROSTOIDIA, 
p. 99. 
Spikelets long - pediceled; panicle 
open (dense in P. hirsutum). 
Spikelets viscid; first glume about 
as long as thesecond; tropical 
species........2..-2+------- 79. P. glutinosum. 
Spikelets not viscid; first. glume 
much shorter than the second. 
Culms erect or rarely spreading; 
blades linear, usually elon- 
gated; spikelets pointed..See Drrrusa, p. 71. 
Culms decumbent at base; 
blades ovate to oblong-lan- 
ceolate; spikelets blunt; 
tropical species. 
Panicles mostly less than 5 
cm. long; plantsglaucous. 77. P. parvifolium. 
Panicles 10 to 20 cm. long; ; 
plants not glaucous....-.. 78. P. millegrana, 
Subgenus PAUROCHAETIUM subgen. nov. 
Perennials; culms tufted, erect, blades not over 7 mm. wide; inflorescence narrow, 
more or less interrupted, the branches short and appressed, the ultimate branchlets 
bearing 1 to several spikelets, produced beyond the uppermost spikelet as a bristle 1 to 
6 mm. long; spikelets 1.5 to 3.5 mm. long, much swollen on the face, glabrous; fruit 
transversely rugose, apiculate. 
The type species is P. distantiflorum Michx. 
This group approaches Chaetochloa in having branchlets produced into bristles, and 
in the shape of the spikelets and rugose fruits. 
Blades elongated, usually more than 15 cm. long, narrowed 
toward the base. 
Spikelets about 3.5 mm. long. .-......---.------------- 5. P. reverchoni. 
Spikelets about 2 mm. long, or less. 
First glume rounded or truncate; second glume about 
as long as fruit........-...----- 2-222 eee eee eee 3. P. chapmani. 
