584 GRAMIXE^E. (GRASS FAMILY.) 



<- *- Culms branching: panicle ample, its base or peduncle included in the upper 

 sheath : spikelets long-pedicelled. 



22. P. autumnale, Bosc. Perennial, nearly glabrous; culms ascending, 

 1 high ; leaves liuear, 2' -3' long, scabrous above; spikelets spindle shaped, 

 their pedicels 2'- 3' long ; upper glumes longer than the acute floret, the lower 

 minute. Dry sand}- soil, not common. 



23. P. capillare, L. Annual, hirsute ; culms erect or decumbent, 1- 

 2 long; leaves broadly or narrowly linear ; spikelets lanceolate or elliptical, 

 2" or less long ; upper glumes twice as loug as the lower, and longer than the 

 obtuse floret. Dry soil, common. 



i- - -i- Culms herbaceous, at first generally simple, but later bearing more or less 

 clustered Jew-flowered branches from the lower joints: leaves mostly short 

 and flat: panicle loose or spreading, l'-6' long. 



M- Spikelets \" or more long : sterile flower neutral (except tliejirst). 



24. P. latifolium, L. Culms smooth, erect ; leaves ovate-lanceolate, 



mostly smooth, the sheaths, especially at the joints, villous ; panicle nearly 

 simple; spikelets large {"2" long), obovate; glumes pubescent, obtuse the 

 upper 2-3 times longer than the lower one; sterile flower 3-androus. Dry 

 rich soil, common. May. Culms 1- 1-J high. Leaves and panicles 3' -4' 

 long, the latter exserted. 



25. P. clandestinum, L. Culms rigid (1- 2 high), branched, naked 

 at the joints ; leaves lanceolate, acuminate, the sheaths papillose-hirsute ; pan- 

 icles small, lateral and terminal, more or less included in the sheaths; spike- 

 lets oblong, smooth or pubescent (1J" long); lower glume rarely half the 

 length of the 7-nerved upper one. Dry sterile soil in the upper districts. 

 Sept. #. 



Var. pedunculatum, Gray? Taller (2 -4 high); leaves 4' -10' 

 long, the sheaths smooth or merely pubescent ; terminal panicle 4' -5' long, 

 diffuse, long-peduncled. River banks, Florida. 



26. P. Joorii, Vasey. Culm 8'- 12' high, dichotomously branched, very 

 leafy; leaves lanceolate, 3' -4' long; panicles shorter than the leaves, few- 

 flowerf d ; spikelets oblong, pubescent, l"long; upper glumes as long as the 

 acute floret, the lower minute. Mississippi, and westward. 



27. P. commutatum, Schultes. Smooth or pubescent; culms l-2' 

 high ; leaves broadly or narrowly lanceolate, 2' -5' long; panicle long-pedun- 

 cled, 2' - 6' long, diffuse ; spikelets oblong, rather acute, 1" - 1-J" long ; upper 

 glumes equalling the acute floret, thrice as long as the lower one. (P. uer- 

 vosum, Elliott.) Dry open woods, common. 



28. P. SCOparium, Muhl., Lam. ? Hairy or woolly all over, except the 

 upper surface of the somewhat rigid lanceolate leaves; culms stout (1-H 

 high), mostly simple ; panicle terminal, exserted ; spikelets obovate (H" long), 

 obtuse, pubescent; upper glume 9-nerved, three times the length of the lower 

 one ; sterile flower neutral. Open woods and margins of fields, in dry soil. 

 May. 



29. P. pauciflorum, Ell. Culms scabrous, soon branching, 1- H high; 

 leaves linear-lanceolate, 2' - 3' long, the sheaths hirsute, bearded at the throat ; 



,0 



