GRAMINE^E. 395 



but is taller and has the joints smooth and the panicle decom- 

 pound and smooth. 



8. P. macrocarpon Torr. : culm erect, simple ; leaves linear-lanceo- 

 late, erect, a little hairy beneath ; joints naked ; sheaths hispid ; pani- 

 cle rather compound, smooth ; spikelets ovate-globose ; abortive floret 

 neutral. 



HAB. Banks of streams. N. J. and Mass. July. 1. Culm 

 3 feet high, straight. Panicle with few spreading flexuous 

 branches. ; * .^ 



9. P. pubescens Lam. : erect, much branched, leafy, softly pubescent; 

 leaves lanceolate, ciliate ; panicle small, few-flowered, free ; spikelets 

 subglobose-ovate, pubescent. 



HAB. Shady woods. Penn. to Car. July. 11. Culm 18 inches 

 high ; nodes and leaves hairy. Panicle with horizontal branches. 



10. P. involutum Torr. : culm cespitose, simple, or a little branched ' 

 at the base ; leaves erect, somewhat rigid, very narrow, at length in- 

 volute ; panicle simple, few-flowered ; florets acuminate ; upper valve 

 of the neutral floret very small. 



HAB. Near Deerfield, Mass. Torr. 2_. Culm, a foot high. 



Panicle terminal, (rarely lateral,) consisting of a few flexuous 

 branches. 



11. P. depauperatum Muhl. : culm cespitose, hairy at the joints ; 

 leaves linear-lanceolate, smooth or hairy ; sheaths pubescent ; panicle 

 few-flowered; blanches in pairs, one of them 2-flowered, the other 1- 

 flowered. 



HAB. Sandy soils. N. Y. and N. J. May, June. If.. Culm*. 

 foot high, jointed. Panicle terminal, erect, with tortuous 

 branches. 



12. P. dichotomum Linn. : culm much branched and dichotomous 

 above ; branches fasciculate ; leaves very numerous, lanceolate, 

 smooth ; panicle simple, capillary, lax ; abortive floret neuter ; upper 

 valve minute, bifid. 



HAB. Dry woods. N. Y. to Car. July Sept. Z/. Culm erect, 

 sometimes decumbent, 8 12 or more inches long. Panicles lat- 

 eral and terminal, with spreading branches. Dr. Torrey des- 

 cribes three varieties of this species. 



13. P. nitidum Lam. : culm slender, simple, erect, smooth ; sheaths 

 bearded at the throat ; leaves very few, broad-linear ; panicle capilla- 

 ry, rather crowded, compound, remote, smooth ; spikelets minute, ob- 

 tuse, ovate, slightly pubescent ; lower glume very small. 



a. ciliatum: culm hairy ; le'aves linear-lanceate, (the lowest one 

 broader) sparingly hirsute, ciliate on the margin; panicle with 

 the branches and flowers pubescent. 



b. ramulosum : culm more branched ; panicle contracted ; branch- 

 es smooth. 



c. gractte : culm very slender, smooth ; leaves very narrow, and 

 with the sheaths smooth ; panicle nearly simple, few-flowered, 

 smooth ; upper valve of the abortive floret minute, entire. ? 



