POACEAE 
48. ARISTIDA L. Mostly low or moderately tall annuals or perennials, 
with narrow often convolute leaf-blades and narrow or sometimes open panicles. 
Spikelets 1-flowered, the ieee inte Mond s: the glumes; glumes 
narrow, acute, acuminate or awn-tipped; lem indurate, narrow, terete, con- 
b 
volute, with a pointed usually minutely buio eallus at 
One hundred and fifty species, of the warmer 
WIRE-GRASSES. 
above in a usually trifid a 
parts of the ics. GRASSES. POVERTY-GRASSES. 
Lemma articulate with the column of the awns: awns nearly 
ase, emn a 
qual. I. TUBERCULOSAE. 
Lemma not articulate. 
Lateral awns minute (less than 1 mm.) or wan II. TERNIPIDES. 
Lateral awns usually well de doped. (reduced i Pis 'dicho- 
tom 
III. DICHOTOMAE. 
Centr aL awn coiled at base: plants annual. 
Central awn not spirally coiled (sometimes all the awns 
loosely contorted in the lower part). 
. OLIGANTHAE. 
Plants annual. 
Plants n ial. 
C OPOHI the branches spreading, naked at 
Am V. DIVARICATAE. 
Panicle narrow, the branches ascending or ap- 
pressed. VI. STRICTAE. 
I. TUBERCULOSAE 
Tufted annual with involute leaf-blades: panicles with the 
1. A. tuberculosa. 
numerous long bristle-like awns spreading in all directions. 
NIPIDES 
Ti, RN 
Tufted erect perennial with wiry stems, long leaf-blades and 
open panicles nearly half the length of the plant. 
III. DICHOTOMAE 
Glumes about equal, mostly 5-7 mm. long; straight portion of 
the central awn uu 2 mm. long; lateral awns short, 
searcely 2 mm. long, e 
Glumes Unc qual the Sod longer, 10-15 mm. long ; straight 
portion of the central awn about 10 mm. long. 
IV. O HAE 
Central awn horizontally spreading or reflexed, much longer 
Nori a lateral. 
mm. long, with a semi-circular or S- 
napa ‘bend at base. 
Ce n 2e awn about 10 mm. long, merely spreading or re- 
Cantal nen AE (or spreading in A. intermedia), about 
2. A. ternipes. 
A. dichotoma. 
4. A. Curtissii. 
5. A. ramosissima. 
6. A. longespica. 
as long as the others. 
Glumes 20- 30 mm. long; awns 4-7 cm. long. 7T. A. oligantha. 
Glumes not over "10 mm. long; awns not over 2.5 cm. long. 8 A. intermedia. 
V. DIVARICATA 
Erect stiff perennial with long leaves and large open few- 
flowered panicles with spreading branches 9. A. patula. 
VI. STRI 
a o fruit 1.5-3 cm. long, slender, Pad. "anis con- 
10. A. spiciformis. 
Neck ‘Of fruit sometimes aoe but not long and slender. 
Sheaths more or E lanos 11. A. lanosa. 
Sheaths not lano 
First glume E to % as long as second. 12. A. gyrans. 
First glume nearly as long as the second or longer. 
Leaf-blades E de densely villous on up- 
per surface near bas 18. A. stricta. 
Leaf- blades. flat or A involute, not densely vil- 
t bas 
Sena aa hori zontally spreading or reflexed 
by a TEAT bend. 
