42 Graminaceae s 
(A. purpurea of How. FI.) 
A, purpurea robusta Pip. (Purple 3-awn) 
BB. Awns of lemma not nearly equal, middle one 0.8—1.7 cm. long; glumes 
not cleft at apex. E. (A. fasciculata.) ; ane 
A. dispersa T. & R. (Bushy 3-awn) = A-divar! 
STIPA NEEDLE-GRASS 
Perennial, tufted. Leaves often rolled up. Spikelets in a terminal panicle; rachilla 
jointed above the glumes. Glumes persistent, narrow, keeled, unawned or rarely with a 
slender awn. Lemma narrow, rigid, convolute, with callus at base, awned; callus 
bearded, usually sharp-pointed; awn terminal, twisted, geniculate. Palet enclosed by the ~ 
lemma, 2-veined. Stamens 3. Grain cylindric, included, often burying itself in the 
soil by the twisting and untwisting of the awn. In dry soil. (Gk. stupe—tow; referring 
to the tow-like plumes of some species.) 
A. YAwn 7.5—Z2Z0 cm: “long: 
B. Glumes 20—30 mm. long including the point, 5-veined; lemma without crown 
of hairs at apex. 
C. Plants glabrous. E.S. comata T. & R. (Needle-grass) 
CC. Plants pubescent. . E. 
S. comata intonsa, Pip. 
BB. Glumes 16—20 mm. long, 3-veined; lemma with crown of hairs at apex. 
E. S. setigera Presl. (Bear-grass) 
AA. Awn 5 cm. or less long. 
D. Awn only slightly pubescent or scabrous. 
E. Callus acute or acuminate, about | mm. long. 
F. Panicle 15—-25 cm. long; lemma and its callus 6—7 mm. long; palet 
14 as long as the lemma. 
G. Sheaths smooth; awn 3.5—6 cm. long. E. 
S, nelsoni Scribn. = 
GG. At least the lower sheaths pubescent; awn 2—3 cm. long. E. 
S. williamsii Scribn. 
FF. Panicle 5-12 cm. long; lemma and its callus about 4 mm. long; palet 
3/4 as long as the lemma. W.C.E. (S. minor.) 
S. columbian Mac. 
EE. Callus obtuse, very short. E. 
S. lemmoni Scribn. 
DD. Awn plumose. 
H.  Ligule | mm. long or less. 
I. Sheaths pubescent. 
J. Awn smooth or rough but not pubescent. E. 
S. viridula Trin. (Feather Needle-grass) 
JJ. Awn pubescent to the second bend. E. 
S. elmeri FP. & B. 
II. Sheaths glabrous. E. (S. oregonensis.) 
S. occidentalis Thurb. (Western Needle-grass) 
HH.  Ligule 2—4 mm. long. E. 
S. thurberiana, Pip. 
ORYZOPSIS MOUNTAIN-RICE 
Perennial, tufted. Leaf-blades wide and flat or narrow and rolled up. Spikelets c 
usually ovoid or oblorg, in a narrow lax few-flowered panicle; rachilla jointed above ~ 
the glumes, not prolonged beyond the palet. Glumes persistent> convex on the back, 
arte r Aye 
