68 POACEAE 
B or some of them hispid, rarely gla- 
: autumnal phase with crowded branch- 
106. P. scabriusculum. 
Leaf-sheaths glabrous: autumnal phase sparingly 
branching. 107. P. cryptanthum. 
XVI. COMMUTA 
Plant glaucous, glabrous: basal leaf-blades ncm 
ously ciliate: vernal stems usually solitary. 108. P. mutabile. 
Plant not glaucous 
Leaf-blades linear : first glume about half as long as f 
the spikele 109. P. equilaterale. 
Leaf-blades lanceolate. 
ems crisp-puberule aoe eae D rigid, 
symmetrical, rarely over vide: spike- 
lets about 2. 5 mm "long: 110. P. Ashei. 
Stems dion or softly puberulent : leaf-blades 
m or lax: spikelets 2.7-3.2 mm. long. 
Stems erect, or autumnal m Jeaning : leaf- 
blades symmetric, broadly ate. 111. P. commutatum. 
Stems decumbent: leaf- blades pee unsym 
metric and falcate, narrowed to the scarce’ y 
cordate base. 112. P. Joorii. 
XXVII. LATIFOLIA 
Leaf-sheaths, at least the lower and those of the 
branches, strongly papillose-hispid. 113. P. clandestinum. 
He glabrous or softly villous. 
Nodes glabrous: spikelets 3.4-3.7 mm. long. 114. P. latifolium. 
Nodes Dearie: spikelets 4-4.5 mm. long. 115. P. Boscii. 
XXVIII. HEMITOMA 
Plant vigorous, extensively rooting, with e rect narrow, . 
often elongate, panicles and acute spikelets. 116. P. hemitomon. 
IX. GYMNOCARPA 
Plant stout, extensively creeping, with aing pan- 
icles and 1o ong narrowly pointed spikelet 117. P. gymnocarpon. 
. Chapmani Vasey. Stem ascending o 
2. P. barbinode Tri Stem erect from a 
long decumbent ios stoloniferous base, 
200—600 em. long: leaf-sheaths villous, or 
d 
glabrous toward t ummit, densely pubes- 
t on the collar: on 15 de, 
glabrous: panicle 12-20 m. long, the rather 
distant subracemose densely iud branches — ^ or spreading: spike- 
lets 3 mm. long. [P. molle (Fl. SE. U. S.]—Ham mocks, ns and waste- 
Ses Coastal Plain, Fla. to Tex.—(W. I., Mez., C. P» , 0. W.) 
3. P. paludivagum H. & C. Stem elongate, as is as 200 em. long, the base 
ereeping, rooting at the m panicle 25-35 em. long; racemes 12-10, pn 
the lower distant, 3 em. long.—In fresh water, Coastal Plain, Fla. and "Tex. 
(Mez. S. A.) i 
4. P. geminatum Forsk. Stem 25-80 em. tall, a a from a somewhat 
decumbent base: ie oe 12-30 em. long, the ra s 12-18, erect, the a 
2.5-3 em. long. [P. paloides (Fl. SE. U. S. ST QW ATER- -GRASS.)— —Mois 
JA, i E prairies ne al Plain, 5 Fla. and Tex.—(W. I., Mez., C. ri 
