23 



Variety ciliare (P. ciliare lietz). 

 Naturalized everywhere. 



3. P. Gliforme,Z/>i». — (Digitariafiliformis ilfii/iZ.). — Calais very slender, 

 1 to 3 feet high, erect, simple, or sparingly branched; leaves narrowly 

 linear, 3 to 10 inches long, erect, somewhat pubescent, and with sheaths 

 hairy, spikes 2 to 8, erect or somewhat spreading, 2 to G inches long; 

 spikelets 1 line long or less, obloug, acute ; empty glumes two, the lower 

 slightly shorter and the upper equaling the flower. 



Sandy or gravelly ground ; Maine to Florida aDd westward. 



4. P. serotinum, Trin. (Digitaria serotina Mx. ; D. villosal^W.). — Per- 

 ennial, extensively creeping, much branched, making a thick carpet; 

 flowering culms 6 to 10 inches ; leaves short, erect, hairy, 1 to 2J inches 

 long, sheaths villous ; spikes 3 to 5, about 2 inches long, narrow ; spike- 

 lets less than lline long, acute, two empty glumes, the first one-quarter 

 to one third as long, and the second nearly as long, as the spikelet. 



North Carolina to Florida and westward. 



Section II. — Trichachne. 



5. P. leucophseum, H. B. K. — Culms stout, 2 to 4 feet high, erect; 

 leaves broadly linear, 1 foot long, scabrous above, ligule ciliate ; pan- 

 icle racemose, contracted, dense, G to 10 inches long, the simple branches 

 numerous, erect, fasciculate, 2 to 4 inches long; spikelets linear-lanceo- 

 late, acuminate, about 2 lines long; lower glume minute, second nearly 

 as long as, and the third equaling, the perfect flower, which is linear-lan- 

 ceolate and mucronate-pointed. Low, rich ground, South Florida, 

 (Chapman, Curtiss, etc.). 



G. P. lachnanthum, Torr. — Culms rather slender, 2 to 3 feet high; 

 leaves much narrower and shorter, panicle shorter, more slender, with 

 fewer and shorter spikes ; spikelets smaller, 1 to 1J lines long, ovate- 

 lanceolate, the perfect flower ovate-lanceolate, acute and mucronate- 

 pointed. 



Mostly on dry hills, Texas, Arizona, and New Mexico. 



Section III. — Subspicata. 



7. P. paspaloides, Pers.— Culms 2 to 3 feet high, decumbent and root- 

 ing below, smooth, stout, leafy; leaves narrow, G to 10 inches long, be- 

 coming somewhat involute, aud with the sheaths smooth; panicle 5 to 

 10 inches long, strict, of 10 to 20 appressed, sessile, simple brauches, the 

 lower ones 1 to 1J inches long, above gradually shorter; spikelets ovate- 

 oblong, obtusish, smooth, 1 to 1 J lines long, imbricate in two rows on the 

 narrow axis, the lower glume truncate-obtuse, one-third as long, and 

 second glume two-thirds as long as the spikelets (also thin and obtuse). 



In ditches or water, Florida to Texas and Mexico. 



8. P. Curtisii, Chap. — Culms 3 to 4 feet high, often rooting at the 

 lower joints; leaves linear-lanceolate, plane, rigid, G to 9 inches long, 

 6 to 9 lines wide, smooth, sheaths smooth or hairy; panicle slender, 



