POACEAE 71 
Leaf-blades elongated ; racemes long and erect. 
Sheaths glabrous. 37. P. glabratum. 
Sheaths densely hirsute. 38. P. Floridanum. 
Racemes finally widely spreading. 
Sheaths glabrous; blades glabrous or ciliate with 
short hairs. | 39. P. giganteum. 
Sheaths densely hirsute; blades ciliate with long 
: airs. 40. P. longicilium. 
228pikelets flat, barely if at all convex on one side. 
Spikelets pubescent. 41. P. Buckleyanum. 
Spikelets glabrous. 
Sheaths, excepting the exterior basal ones, glabrous, or 
the lower sometimes pubescent at the summit. 
Stems and sheaths much compressed, the former 
rather slender. 
Spikelets elliptic. 42. P. lividum. 
Spikelets orbieular or nearly so. 
Leaf-blades glabrous. 
Spikelets 2-2.5 mm. long. 43. P. praecox. 
Spikelets 3 mm. long. 41. P. glaberrimum. 
Leaf-blades hirsute : 
On the upper surface only : spikelets circular 
or nearly so. 45. P. tardum. 
On both surfaces, strongly so on the lower: 
spikelets broadly obovate. 46. P. Kearneyi. 
Stems and sheaths not much compressed, the former 
stout. 47. P. amplum. 
Sheaths densely hirsute. 48. P. Curtisianum. 
TiSpikelets acute, ciliate with very long hairs. 
Spikelets about 2.5 mm. long; racemes numerous (usually 10 
or more). 49. P. Vaseyanum. 
Spikelets 3.5-4 mm. long; racemes few to several (usually less 
than 8). 50. P. dilatatum. 
**Stem single, from a long scaly rootstock. 
Seales of the rootstock appressed-pubescent: rachis of the ra- 
cemes not winged, the spikelets scattered. 51. P. bifidum. 
Seales of the rootstock glabrous: rachis of the racemes winged, 
the spikelets crowded. i : 92. P. solitarium. 
2. Racemes in pairs at the summit of the stem, rarely in 3’s or with 
another raceme below. 
Stems tufted : racemes long and slender, the spikelets about 1.5 mm. 
53. P. conjugatum. 
ong. : 
Stems from long rootstocks: racemes short and stout, the spikelets 
exceeding 2 mm. long. 3 
Spikelets ovate, 2.5-3 mm. long, pubescent; midnerve of the 
second scale present. : 
Spikelets ovate-lanceolate, 3-4 mm. long, glabrous; midnerve : 
of the rugose second scale suppressed. 55. P. vaginatum. 
1. Paspalum mucronàtum Muhl. Stems 1.5-8 dm. long, compressed, from a float- 
ing or creeping base, branched: leaf-sheaths loose or inflated, glabrous or hirsute ; blades 
8-30 em. long, 6-25 mm. wide, acuminate, rough: racemes 20-100, scattered, or sometimes 
apparently whorled, 1-8 cm. long, slender, spreading, the rachis extending in an acumi- 
nate point beyond the spikelets, the wings membranous and nearly enclosing the spikelets 
at maturity : spikelets singly disposed in two rows, elliptic, 1.2-1.5 mm. long and about 
0.6 mm. wide, pubescent. [P. fluitans Kunth. ] 
In water, Virginia to southern Illinois, Missouri, Florida and Texas. Also in tropical America. 
54. P. distichum. 
Fall 
2. Paspalum membranàceum Walt. Stems sometimes 6-8 dm. long, compressed, 
creeping at the base, much branched: leaf-sheaths compressed, loose; blades 3-8 cm. 
long, 4-6 mm. wide, smooth: racemes 3-7, erect, 2-3 cm. long, the rachis not extending 
beyond the spikelets, the wings broad and nearly enclosing the spikelets at maturity : 
spikelets singly disposed in two rows, 2-2.3 mm. long and 1.3-1.5 mm. wide, oval, gla- 
brous. [P. Walterianum Schult. ] 
In moist or wet soil, New Jersey and Delaware to southern Ohio, Florida and Texas. Fall. 
3. Paspalum blepharophyllum Nash. Stems tufted, 4-8 dm. tall: leaf-sheaths 
glabrous, even on the margins; blades linear-lanceolate to lanceolate, glabrous on both 
surfaces, ciliate on the margins, 2.5 dm. long or less, 8-16 mm. wide: racemes usually 
single, commonly 6-8 cm. long, sometimes longer: spikelets in pairs, 2 mm. long and 
1.3-1.6 mm. wide, broadly obovate or oval, the first scale 3-nerved, usually pubescent with 
short hairs, the second scale 3-nerved, or sometimes 2-nerved by the suppression of the 
midnerve, glabrous. 
In sandy soil, Florida to Louisiana. Spring and summer, 
4. Paspalum propínquum Nash. Stems tufted, 8-10 dm. tall: basal leaf-sheaths 
pubescent, the remaining ones glabrous ; blades glabrous on both surfaces, ciliate on the 
margins with stiff hairs, linear, erect or nearly so, 5-20 em. long, 5-10 mm. wide : racemes 
rather slender, 8-12 cm. long, in 1’s or 2’s: spikelets in pairs, on shorter pubescent pedi- 
