62 POACEAE 
Leaf-sheaths, or some of them, pape 
hispid : spikele ets 3-4 mm. lon 
PEE Eu turgid, blunt, nor " strongly 
d (see, however, P. roanokense and 
Ligule of conspicuous hairs, usually 3-5 
mm. long: spikelets pubes ent. 
rr dies glabrous or cay the lower- 
ost somewhat pubescent. 
Leaf. sheaths strongly DUbe ced 
ccn panicle- -branches with vis- 
cid spo 
Spikelets usually obovate or elliptic 
L s of the mid-stem elongate, 
n 1.5 em. wide: stems usu- 
ally tall: Spikelets pointed, ab- 
E so in the velvety P. sco- 
par 
Leaf-blades of the mid-stem not elon- 
ie E somewhat so in P. equilat- 
Blades cordate, 1-3 em. wide (5-12 
P. Ashei): spikelets 
pube ed 
Spikelets 2.5-3 m long: leaf- 
sheaths PE ‘or minutely 
puberulent. 
Spikelets 3-5 mm. long (some- 
times but 2.7 mm. long in 
a pe sheathed P. clan- 
Blades ee cordate (somewhat in 
P. annulum), less than 1 cm. 
wide. 
Sheaths crisp- or appressed-pu- 
bescent: blades firm : spikelets 
pubescent. 
Sheaths glabrous (sparsely pi- 
lose in P. curtifolium and 
often in P. annulum). 
spikelets x 5 n long, 2: less 
1.6-1.7 nue). 
Vernal s sl En A dM but not 
de nem rarely less than 
40 c igh: D E 
= 9 T lon 1.5 
n P. microcarpon nr P. 
Puer ule ccu 
Lower internodes short, up- 
at base: spikelets n 
Ead ovate, 2.7-2.0 m 
ZW internodes not short 
leafy throughout: spike- 
lets elliptic or obovate, 
pum more than 2.5 mm. 
I. DISTANTIFLORA 
PED oe erect, with narrow erect or appressed 
XXIV. OLIGOSANTHIA. 
XVIII. SPRETA. 
XIX. LANUGINOSA. 
XXI. SPHAEROCARPA. 
XXV. SCOPARIA. 
XXVI. COMMUTATA. 
XXVII. LATIFOLIA. 
XX. COLUMBIANA. 
XXII. ENSIFOLIA. 
XVI. NUDICAULIA. 
XVII. DICHOTOMA. 
1. P. Chapmani. 
