498 
florets, the anterior with a short usually divergent awn on one side, below the mid- 
dle. (Pleuraphis mutica Buckl.)—High plains and mesas, western ‘Texas to Arizona. 
3. H. Jamesii(Torr.) Benth. Rootstock creeping, strongly rooted: culms 2to5 dm. 
high in small tufts, rarely bunched: leaves inostly involute rigid, pungent-pointed, 
hispid: spikes 4 to 6 cm. long, rather densely flowered, often purple: spikelets 7 to 
9mm. long; hairs at the base about 3 mm. long; empty glumes all ciliate on the 
margins; those of the central spikelet 4 or 5-awned on the back; the anterior ones 
of the lateral spikelets awned at one side above the middle, the awns exceeding the 
cluster. (Pleuraphis Jamesii Torr. )—High plains west of the Pecos and northwestward 
to Colorado and Nevada. 
NAZIA Adans. 
Inflorescence in solitary terminal spikes: spikelets in short pedun- 
culate or almost sessile clusters of 2 to 5; the clusters single on all 
sides of the terete axis: second empty glumes turned to the outside 
surrounding the cluster like an involuere, coriaceous and beset with 
hooked spines; the first glume small and inconspicuous; floral glume 
membranaceous acute; palet present in the perfect florets: some of 
the florets in each cluster imperfect. (Tragus Hall.) 
1. N. racemosa (Hall) Kuntze. Annual: culms 2 to3 dm. high, branching: leaves 
bristly ciliate on the margins; spikes 4 to 8 em. long, often included at base in the 
vaginate upper sheaths: spikelets 3 to 4 mm. long. (Tragus racemosus Hall. )—Intro- 
duced and abundantly naturalized near the coast and in the Rio Grande Valley, 
14. PASPALUM L. 
Spikes unilateral, single and terminal, subdigitate or paniculate: 
spikelets in one, two or three rows, plano-convex, obtuse or subacute, 
awnless, each with one perfect floret: glumes 3, the outer ones mem. 
branaceous, equal or in a few species the outer one smaller; the floral 
glume more or less convex, becoming indurated, embracing the shorter 
flat palet of the same texture. 
§ 1. Spikelets more or less secund along the rachis, with the backs of the floral glumes 
turned inward or toward the rachis. —EUPASPALUM. 
* Rachis of the spikes membranaceous, dilated, somewhat conduplicate, nearly inclosing the 
small spikelets at maturity. 
1. P. fluitans (E1l.) Kth. Culms decumbent, often rooting at the nodes: leaves 
broadly lanceolate, 5 to 10 mm. broad: spikes numerous (15 to 40) in panicles 1 to 2 
dm. long; the rachis extending beyond the spikelets, taper-pointed : spikelets thinly 
pubescent, about 1 mm. long. (2. Ceresia fluitans Ell.)\—Muddy banks, near or in 
water, eastern Texas to Florida. 
2. P. Walterianum Schultes. Culms decumbent and rooting at the nodes, 
branching: leaves narrowly lanceolate, 3 to5 mm. broad: spikes few (3 to 7) in pan- 
icles less than 1 dm. long; rachis blunt pointed, not extending beyond the spike- 
lets: spikelets smooth, nearly 2 mm. long.—Low, wet ground, eastern Texas to New 
Jersey. 
** Rachis flat or subterete, not inclosing the spikelets. 
+ Spikes single and terminal, or a terminal pair, or 1 terminal with 1 (rarely 2) 
approximate. 
3. P. monostachya Vasey. Culms tufted, erect, rigid, 5 to 10 dm. high, 
simple: leaves narrow, convolute, 2 to 3 dm, long: spike erect, 1.5 to 2 dm, long: 
spikelets closely imbricated on the narrow rigid rachis subacute, 3mm. long; the 
