Part 2, 1912] POACEAE 137 
5- or 6-nerved, the midnerve excurrent as a hispid awn between the lobes, one lobe so small 
that it resembles a lateral appendage on the inner side of the scale, the second scale linear- 
oblong, 4- or 5-nerved, the parallel nerves all vanishing below the apex, none of them excurrent, 
the flowering scales 2 or 3, long-ciliate at the 2-lobed apex, the lobes rounded, 2- or 3-nerved, 
one lateral nerve sometimes being suppressed, the midnerve terminating at the sinus, the 
lateral nerves vanishing below the apex; central spikelet with the empty scales 2-lobed, long- 
ciliate on the margins above, equilateral, the apex divided into about 4 awns or awned lobes, 
the midnerve usually excurrent below the middle as a hispid awn shorter than the scale, the 
flowering scale 3-nerved, the lateral nerves vanishing below the apex, the midnerve excurrent 
between the obtuse lobes as a short hispidulous awn. 
TYPE LOCALITY: Northern Texas. 
DISTRIBUTION : Western Texas to California, and south to Durango and Lower California. 
ILLUSTRATIONS: Bull. U.S. Dep. Agr. Agrost.7:/. 19; Bull. U. S. Dep. Agr. Bot. 121: p/. 17. 
2. Pleuraphis Jamesii Torr. Ann. Lyc. N. ¥Y.1: 148. 1824. 
Hilaria Jamesii Benth. Jour. Linn. Soc. 19: 62. 1881, 
Stems 1.5—5 dm. tall, erect, simple, usually hispidulous or puberulent below the inflores- 
cence and below the nodes which are generally barbed; leaf-sheaths smooth or rough, gla- 
brous; blades confined mainly ‘o the lower portion of the stem, up to 2 dm. long, 2-3 mm. 
wide, spreading or erect, the margins involute, rough on the lower surface, the upper surface 
densely puberulent; inflorescence 3-7 cm. long, the axis commonly puberulent; spikelet-clusters 
7-9 mm. long, about twice as long as the basal hairs; lateral spikelets with the empty scales 
linear-oblong, 3- or 4-nerved, the nerves parallel, strongly hispidulous all over on the outside, 
ciliate on the margins, 2-lobed, the first scale shorter than the second, strongly inequilateral, 
the one lobe very narrow, as long as the other lobe or but little shorter, the midnerve 
excurrent as a hispid awn between the lobes, much longer than the scale, the remaining nerves 
vanishing below the apex, the second scale entire or minutely bifid at the apex, the nerves 
vanishing at or below the apex or the midnerve sometimes excurrent asa short hispid point, 
the flowering scales usually 2, 3- or rarely 5-nerved; central spikelet with the empty scales 
long-ciliate, the apex divided into 4-8 long-awned lobes, the midnerve excurrent usually at 
or below the middle as a hispid awn longer than the scale, the flowering scale 3-nerved, or 
rarely with an additional nerve on one side, the midnerve excurrent between the lobes as a 
short hispid awn. 
TYPE LOCALITY: On the high plains of the trap formation at the sources of the Canadian River. 
DISTRIBUTION : Wyoming to Nevada, and south to western Texas and southern California. 
ILLUSTRATIONS: Bull. U. S. Dep. Agr. Agrost.7: /. 20; Ann. Lyc. N. ¥. 1: pl. 10; Vasey, 
Agr. Grasses U. S. p/. 23; ed. 2. p. 25; Bull. U. S. Dep. Agr. Bot. 1: pl. 10; 6: pl. 6. 
3. Pleuraphis rigida Thurb. Bot. Calif. 2: 293. 1880. 
Hilaria rigida Benth.; Vasey, Grasses U. S. 16. 1883. 
A tall perennial with the leaves and stems densely woolly-pubescent, sometimes glabrate 
in age. Stems up to 8-10 dm. tall, finally branching; leaf-sheaths crowded and overlapping 
below, shorter than the internodes above; blades erect or ascending, up to 8 cm. long, 3-5 mm. 
wide, involute on the margins; inflorescence 3-8 cm. long, the axis puberulent; spikelet- 
clusters 8-10 mm. long, 2-3 times as long as the basal hairs; lateral spikelets with the empty 
scales ciliate above the middle, the apex fimbriate, the first scale narrowly obovate-cuneate, 
deeply 2-lobed at the apex, sometimes to the middle, 4- or 5-nerved, the midnerve excurrent 
about the middle of the scale into a hispidulous awn longer than the scale, the one lobe very 
narrow, usually 1-nerved, the nerve running out into a short awn, the other lobe much broader, 
the nerves vanishing below the apex, the second scale commonly unequally 3-lobed at the 
apex, 5-7-nerved, 1 or 2 of the nerves excurrent between the lobes as short awns, the flowering 
scales 2 or 3, 3-nerved, 2-lobed at the ciliate apex, the midnerve usually excurrent as a short 
awn; central spikelet with the empty scales ciliate with very long hairs, with a long hispid awn 
arising from the back below the middle, the apex of the scale with 6-8 long awns or awned 
lobes, the flowering scale shortly 2-lobed at the apex, the lobes ciliate, 3-nerved, the midnerve 
excurrent as a short awn. 
TYPE LOCALITY: Fort Mohave, California. . : ; : 
DISTRIBUTION: Southern Utah to Arizona, southern California, and Lower California. 
ILLUSTRATIONS: Bull. U. S. Dep. Agr. Agrost. 7: f. 22; Bull. U.S. Detp. Agr. Bot. 12?: pJ. 2. 
