390 ORDEK 155. GRAMINE.-E. 



a shearned axillary one below ; spikelets small, J", in pairs, but seeming 2-roweo, 

 very smooth n Pry or wet, Mass, to HI., and S. Aug. 



2 P. laeve MX. (p) Cu'm erect, If 3f; Ivs. broad-linear, hairy at base or smooth; 



spikes 3 5; spikelets (a. b) single, contiguous", in 2 rows on the narrow straightish 

 rachis, round and smooth, 1^". 2i Grassy banks, Ct. to Ind., and S. Aug. 

 /3. nltt**iininn. Strict, tall ; sheaths flattened close on the spikes. 



3 P. ang-ustilollnm Le Cont. Cuitt. wiry, 2 3f; Ivs. linear-filiform, compressed- 



carinate ; spikes 2 or 3, 1 2" ; rachis narrow, flexuous ; spikelets round-oval, brown, 



1", in 2 rows. Whole plant glabrous, if Wet places. Ga., Fla., La. [and S, 



0. ttnitr. Spikes 4 or 5, very slender, 3-rowed ; Ivs. and sheaths ciliate. N. J., 



1 P. praecox Walt. Culm erect, 8 4f; Ivs. long, narrow, smooth; sheaths purple, 



smooth or hairy; spikes 3 6, bearded at base, dense ; rachis straight and flat; spkl. 



orbicular, in 3 rows, often brown, if Swamps, S. May, June. 



5 P. diiKjphj Hum Ell. Culm rigid, erect, 2 3f; Ivs. linear, and with the sheaths 

 hairy all over; spikes 2 5, large, 2 4' ; spkl. orbicular-oval, near 2", in 2 or 3 rows 

 ' under the very flexuous rachis. 11 Dry fields, S. July Oct. 



ft. Floridnntint. Lvs. long and narrow ; spikelets in 3 rows. Damp, S. 

 > P. vlrgatum L. Culm H 3f; Ivs. broad-linear, ciliate near the base; spikes 

 3 12. 24' ; rachis broad, but narrower than the 34 rows of small (1") roundish 

 spiki-lcts; glume 3-veined. (T) Moist soils, S. July Oct. 

 /3. tin<li.ii \tni. Upper glurae (pale) undulate-rugous at edge. 

 y. I til i folium. Lvs. very broad (6 !>") : spikelets larger (If). 



7 P. laoemulosiim N. Culm erect, firm, 2 3f: Ivs. long, linear, soft-hairy; spikea 



3 4. raceme-like, 26'; t.pkl. oval, in remote pairs, 1J", the glume 5-veined, tawny. 

 V Dry soils, S (P. interruptum C-B.) Aug., Sept. 



8 P. 11 ui (a ns K. Culms floating or ascending, 12 ?()'; Ivs. lance-linear, on open 



sheaths; spikes 20 ?0, 12^'. rachis 1" wide, flat, pointed, out-running the minute 

 white spikelets beneath them. (T) River swamps. 111. to Va., and S. Oct. 



!> P. \Viiltcriu.n inn Schlt. Culm and Ivs. as in P. flutians. Spikes 35, 23', 

 partly sheathed; rachis not out-running the white (1") spkl. Wet, N. J., and S. Jl.-f 



1 1> P. Dlgltaria Poir. Assurgent, 1 2Jf; Ivs. broad-linear, flat, on long sheaths, 

 spikes slender, 35', a pair at top of the long ped. and some axillary sheathed be- 

 low ;-jgpkl. lanceolate, rachis flattened vertically, v Woods, Va., and S. ,11. Sept. 



IIP. conjugatum Berg. Erect, 1 2f; Ivs. short (-1 4'); spikes a pair at top, 

 (rarely axillary), very slender, 3' ; spikelets minute, white, ovate. (T) N. Orl. 



J 2 P. glaforum (Gaud.) Culms decumbent, spreading, 8 15'; Ivs. !>hort ; spikes 

 24. spreading, 1 2', slender; spkl. ovate, purple. }", 2-rowed ; upper pi. equaling 

 the fl., lower minute. (T) Sandy fields, N. J., and S. (P. ambigunm, DC.) Aug. -t- 

 3 P. disticlium L. Culms assnrgent, 12 18'; Ivs. broad-linear; spikes 2 or 3, 

 erect, near the top, If 2f ; rar.his linear, narrower than the 2 or 3 rows of whitish 

 ovate 1J" spikelets. 11 Wet grounds, S. States. Plant smoothish. July, Aug. 



1 4 P. tristielnim Le C. Culm ascending, 1 2f; peduncles from the upper joint, 

 1 3, filiform, each bearing 3 filiform suberect spikes; spkl. whitish, lance-ovate, mi- 

 nute ; rachis flexuous. Wet places. 2{ Ga., Fla., to La. Aug. 



I n P. filiforme Swtz. Culm filiform, erect, 1 Hf; Ivs. short; spikes 2 , filiform, 

 erect ; rachis filiform; spkl. oblong, f", in 3's ; lower glume obsolete, upper as long 

 as the flower. Dry soils, (T) Ms. to Ky., and S. 



1 G P. Ncroliiium Flgg. Decumbent, rooting, hairy-villons ; Ivs. short (12)', 

 lance-linear ; branches each with 3 5 filiform digitate spikes ; rachis straight ; spkl. 

 lance-ovate, striate, minute. V. Sandy fields. S. C. to La. Sept., Oct. 



17 P. sangulnale Lam. Crab or Finger G. (d) Erect, 1 2f, Ivs. and sheaths 

 oftener hairy; spikes 5 9, digitate, spreading, 4 6'; rachis flexnoua ; tpkl. (c) 

 oblong-lanceolate, 1J", upper gl. (c't I as long as the flower, (e) lower one minute. ( 

 Wssre grounds Aug. Oct. % 



