graminejE. (grass family.) 577 



^ 3. AULAXANTHUS. — Spikelels awnless, single, loosely racemose on the trert 

 branches of the compound contracted panicle : lower (jUime wanting, the upper one 

 5-ribhed, ven/ hairi/: perennials. 

 28 P. ignoratum, Kumh. Culms erect, simple, smooth ; leaves linear- 

 lanceolate, ]niiigeiit, strongly nerved, fringed on the margins, the lower ones 

 widely spreading ; panicle racemose ; spikelets ohovatc; sterile flower 3-androus; 

 anthers and stigmas yellow. (Aulaxanthus ciliatns, A7/.) — Dry gravelly soil, 

 Florida to North Carolina. July and Aug. — Culms 2° -3° high. Leaves and 

 spikelets pale. 



29. P. rufum, Kunth. Leaves erect, linear, smooth, elongated ; sterile 

 flower neutral ; anthcre and stigmas purple ; otherwise like the preceding. (Au- 

 laxanthus rufus, Ell.) — Pine-barren swamps, Florida to North Carolina. Sept. 



— Leaves and spikelets purplish. 



^ 4. ECHINOCHLOA. — Spikelets crowded on one side of the racemed or pani- 

 cled spikes: glumes and lower palea of the sterile flower hispid-pointed or owned. 



30. P, Crus-galli, L. Culm stout (2° -4° high), branching ; leaves very 

 long, broadly linear, rough; sheaths smooth, rough, or hispid; spikes (I' -2' 

 long) very numerous, crowded in a long raceme ; spikelets clustered ; glumes 

 and lower palea of the sterile flower strongly hispid on the nerves, awn-pointed 

 or long-awned ; fertile flower rough-pointed. — Wet places, Florida, and north- 

 ward. Aug. and Sept. (p — Awns pale or purple. 



31. P. Walteri, Ell. Culms (l°-2° high) branching; leaves linear, 

 smooth, like the sheaths; spikes 5-12, distant, erect or apprcsscd (^'-1' long), 

 bearded at the base ; spikelets in 3 rows, awnless ; glumes and lower palea his- 

 pid on the nerves, pointed ; fertile flower barely pointed ; rachis rough. — Damp 

 soil, Florida to North Carolina. July- Sept. Q) — Spikelets purplish. 



32. P.? molle, Michx. "Spikes panicled, alternate, expanding, flower- 

 ing on one side; spd^clets approximate, pedicillate, on one side, awnless," Ell. 



— Sea islands of South Carolina, Elliott. Aug. and Sept. IJ. — Culm 4° -6° 

 high, smooth below, downy above. Leaves 12'- 18' long, smooth, fringed at 

 the throat. Spikelets 2-3 together on a villous rachis, hairy. Plant salt and 

 bitter. 



§ 5. ORTIIOPOGON. — Panicle simple, spiked: spikes fewflowercd, distant: 

 glumes equal, liairy, the lower one long-awned : upper and lower palece of the sterile 

 flower short-awned. 



33. P. hirtellum, L. Culms slender, ascending from a creeping base; 

 leaves (l'-2'long) ovate-lanceolate, thin; sheaths hairy; spikes about .5, dis- 

 tant, 5-8-flowercd; awns (often purple) clammy. — Shady woods, Florida to 

 North Carolina. Aug. and Sept. y. — Culms l°-2° long, branched, the erect 

 portion 6' -12' high. 



50. SETARIA, Beauv. 



Erect annual grasses, with flat leaves and the spikelets of Panicum proper, 

 but crowded in cylindrical spike-like panicles ; the short pedicels bearing one or 

 more bristles, which usually exceed the spikelets. 

 49 



