50 POACEAE 
axis, forming a white or tawny silky panicle. Spikelets lanceolate, in pairs, 
dor -pedicelled in 2 rows along one side of a narrow rachis: first glume minute, 
glabrous: second glume and sterile lemma 
about as long as the fruit, 3—5-nerved, co- 
piously silky: fertile lemma cartilaginous, MA 
lanceolate, acuminate, brown, the flat white 
hyaline margins broad.—About 12 species, in 
temperate and tropical America. 
1. V. insularis (L.) Chase. Stem 1-1.5 m. 
tall, rather stout: leaf-blades as much a s 30 
em. long and 1.5 em. wide: panicle 15-30 
—(&iLKY-GRASS.)—Moist soil and waste- 
plaees, Coastal TN Fla. and S Tex.—(W. I., Mez., C. A., S. A.) 
20. SYNTHERISMA Walt. Erect or prostrate annuals or perennials, the 
slender racemes digitate or aggregate on a short axis. Spikelets in 2’s or 3’s, 
subsessile or short-pedicelled, alternate in 2 rows on one side of a 3-angled rachis, 
lanceolate or elliptic: first glume minute or wa nting: second glume equalling 
the sterile lemma or shorter: fertile lemma cartilaginous, the hyaline margins 
pale. [Digitaria Haller ]—About 60 species, in tropical and temperate regions. 
——FINGER-GRASSES. CRAB-GRASSES.—Some species are pernicious weeds. 
Rachis of AA winged, or flat-margined : ereeping annuals. I. SANGUINALIA. 
Rachis of raceme wingless, triangular: plants not creeping, an- 
nual or oraa II. FILIFORMIA. 
I. SANGUINALIA 
Rachis bearing scattered aa fine hairs uc. rarely wanting): spikelets narrow, 
cuminate, nearly glabro 1. S. digitatum. 
irs. 
Leaf-sheaths glabrous: fertile lemma brown. 
S yd 
pi elets 2 T 2. S. Ischaemum. 
Spikelets 1.7 ng. 3. S. floridanum. 
Leaf-sheaths hispid | villous: fertile lemma 
Spikelets 1.5 mm. long: pedicels terete, glabro 4. S. serotinum. 
Mops 2.5-3.0 mm on ee pedicels angled, oa ae 
Second gare much smaller than the spikelets: eo 
glume nt. 5. S. sanguinale. 
Second ‘gume equalling the spikelets ; first glume ob- 
6. S. Simpsoni. 
i II. FILIFORMIA l 
Fertile lemma pale or gray: plant perennial. T. S. pauciflorum. 
Fertile lemma dark-brown : plant erect or at least not rooting at 
P base, annual or sometim ud apparently perennial. 
Second glume and sterile lemma eee 8. S. gracillimum. 
Second gl ma a e ouneacent: 
Spikelets about 1.5 mm. long 
eaf-blades folded o or involits, flexuous. 9. S. paniceum. 
Leaf- blades flat. 10. S. filiforme. 
Spikelets 2-3 mm. long. 11. S. villosum. 
1. S. digitatum (Sw.) A. Hitche. 1 n and iu m the 
aspect of S. sanguinale: stem as much as 60 em. long or rarely 1 : leaf- 
d papillose -hirsute: racemes A mostly 9—10, El e 
ing, 5-10 cm. long: spikelets about 2 mm. long: first glume minute; second 
