578 GRAMTNE.E. (GRASS FAMILY.) 



* Bristles roughened downward. 



1. S. verticillata, Beany. Culms sparingly branched; leaves linear- 

 lanceolate, rough above ; spike cylindrical, compact, somewhat interrupted be- 

 low (2' -3' long) ; bristles short, single or by pairs. — Around dwellings, North 

 Carolina, and northward. Introduced. — Culm 2° high. 



* * Bristles roughened upward. 



2. S. glauca, Beauv. Culms smooth, slightly compressed ; leaves linear- 

 lanceolate, rough above; spike nearly simple, cylindrical; bristles 6-10, in 2 

 clusters, longer than the spikelets; perfect flower transversely wrinkled. — Var. 

 LfiViGATUM (Panicnm hevigatum, Ell.) has a more flattened culm, longer, nar- 

 rower and smooth leaves, and the perfect flower obscurely wrinkled. — Culti- 

 vated ground, the var. in damp soil along the coast, Florida to North Carolina. 

 — Culms l°-3° high. Spikes 2' -3' long, pale or purplish. 



■ 3. S. viridis, Beauv. Culms smooth, terete ; leaves lanceolate or linear- 

 lanceolate, rough ; spikes compound, cylindrical, dense ; bristles 1 - 3 to each 

 spikelet; perfect flower finely striate and dotted lengthwise. — Around dwell- 

 ings. Introduced. June -Sept. — Culms 1°- 2° high. Spikes 1'- 2' long. 



4. S. COrrugata, Sennit. Culms, narrow (2" wide) leaves, and sheaths 

 rough; spikes compound, cylindrical, dense, erect or bending; spikelets 6-10 

 in a cluster; bristles one to each spikelet, elongated; perfect flower obtuse, 

 strongly wrinkled. (Panicnm corrugatum. Ell.) — Dry soil, Florida and Georgia. 

 July and Aug. — Culms 2° - 3° high. Spikes 3' - 6' long, purple. 



5. S. COmposita, Kunth. Culms smooth ; leaves linear-lanceolate, the 

 fringed sheaths rough-hairy at the throat; spikes loose, compound, the lower 

 clusters scattered ; bristles single or by pairs, many times longer than the spike- 

 lets ; perfect flower acute, with faint transverse lines. — Dry sandy soil along 

 the west coast of Florida, Apalachicola to Key West. June-Aug. — Culms 

 2° -4° long. Leaves 1° or more long. Spikes 6'- 12' long. 



6. S. Italica, Kunth. Culms tall (4° -8° high), smooth, branched ; leaves 

 ||'-1' wide) very rough; spikes compound (6'- 18' long), cylindrical, dense, 

 the lower clusters scattered; bristles 1-2 to each spikelet, elongated; fertile 

 flower smooth and even. — Swamps along the coast, Florida to North Carolina. 

 July— Sept. — This, and Penicillaria spicata, Wil/d., are commonly cultivated, 

 under the name of MlLLET, as green food for cattle. The latter seems to be 

 the Panicum cenchroides, Ell. 



51. CENCHRTJS, L. Cock-spur. 



Prostrate or creeping grasses, with the spikelets of Panicnm proper, hut en- 

 closed, 1 -several together, io Bpiny or bristly, at length indurated and deeid- 



nous involucres; the latter burr-like, and arranged in a terminal spike. Stamens 

 3. Styles united below. 



l. C. cchinatus, L. Spikes cylindrical, composed of 20 or more globular 

 involucres (.'i'--i' long) ; Involucre downy, spiny above, and with a row of rigid 

 barbed bristles above the base, 3-5-flowered; culms ascending. — Fields and 



