110 POACEAE 



longer, stouter, beautifully plumose below : spikelets very numerous, densely crowded, 

 about 4 mm. long. 



In damp places, southern peninsular Florida. Also in tropical America. Summer and fall. 

 MISSION GKASS. 



39. PENICILLARIA Beauv. 



Tall grasses, with flat leaf-blades and dense cylindric panicles. Spikelets in pairs on a 

 short pedicel, surrounded by bristles, persistent ; bristles little if at all exceeding the spike- 

 lets, the outer ones short and merely hispidulous, the inner ones plumose. Scales 4, the 

 3 outer membranous, the fourth scale shorter, firmer, enclosing a palet of similar texture 

 and a perfect flower. Stamens 3. Styles usually distinct. Stigmas plumose. 



1. PenicQlaria spicata (L. ) Willd. Stems erect, 1 m. tall or more, densely and softly 

 pubescent below the inflorescence, leafy : leaf-sheaths strongly ciliate on the margins with 

 long hairs ; blades 4 dm. long or less, 6-10 mm. wide, long-acuminate : panicles 1-3 dm. 

 long, cylindric, 1-1.5 cm. in diameter : outer bristles shorter than the spikelet, numerous, 

 slender, merely hispidulous, the inner ones stouter, few, about equalling the spikelet in 

 length, plumose : spikelets about 4 mm. long. 



In fields and waste places, and along (roadsides, Alabama and Mississippi. Summer and fall. 



40. STENOTAPHRUM Trin. 



Perennial grasses, creeping and branching at the base, with compressed stem, flat or 

 convolute leaf -blades, and a terminal spike or spike-like panicle. Spikelets acute or acumi- 

 nate. 2- (rarely 1-) flowered, in 2's-4's in short spikes which are embedded in the alternate 

 notches on one side of the broad and compressed rachis. Scales 4, rarely 3, the 2 outer 

 empty, the first small, rarely wanting, the second equalling or a little shorter than the 

 spikelet, the third scale similar to the second, enclosing a palet and a staminate flower, 

 rarely empty, the fourth scale more rigid than the others, enfolding a palet of similar 

 texture and a perfect flower. Stamens 3. Styles distinct. Stigmas plumose. 



1. Stenotaphrum secundatum ( Walt. ) Kuntze. Stems compressed, prostrate and 

 rooting at the lower nodes : leaf -sheaths compressed, glabrous, keeled ; blades flat, or 

 folded when dry, linear, rounded at the apex, usually less than 1 dm. long, sometimes 

 longer, 4-10 mm. wide : spikelets 5-10 mm. long, immersed in one side of a broad com- 

 pressed rachis, 3.5-5 mm. long. 



In sandy soil, South Carolina to Florida and Texas. Also in tropical America. Spring to fall. 

 SHORE GRASS. 



41. OLYRA L. 



Usually tall grasses, with broad flat leaf-blades, which are contracted into a petiole- 

 like base, and terminal or axillary panicles. Spikelets unisexual, monoecious : staminate 

 spikelets arranged along the panicle branches below the summit ; scale 1, usually awned ; 

 palet as long as the scale, 2-nerved ; stamens 3. Pistillate spikelets terminating the main 

 branches of the panicle, much larger than the staminate ; empty scales 2, usually awned, 

 membranous, the third scale chartaceous, indurated in fruit ; styles 2, united at the base. 



1 O'yra la if 51- a L. Stems finally branched : leaf -blades contracted at their junc- 

 tion with the sheath into a petiole-like base, oblong to broadly lanceolate, rather abruptly 

 acuminate, the primary ones 1.5 dm. long or less, 2-4 cm. wide : panicle triangular or 

 ovate, its branches spreading or ascending : staminate spikelets lanceolate, 4-5 mm. long, 

 exclusive of the awn : pistillate spikelets ovoid, acuminate, 8-10 mm. long, exclusive of 

 the awn. 



In dry places, southern peninsular Florida. Also in tropical America. Summer. 



42. HYDROCHLOA Beauv. 



Slender branching monoecious aquatic grasses, usually floating, sometimes creeping, 

 with narrow flat leaf-blades and spicate inflorescence. Spikelets small, of two kinds, the 

 staminate in a slender short terminal spike, the pistillate in few-flowered spikes in the upper 

 leaf-axils, the spikes but little exserted from the sheaths. Scales 2, a little unequal, mem- 

 branous, concave, awnless, palet wanting. Stamens 6. Styles short, distinct, somewhat 

 laterally attached to the apex of the ovary. Stigmas elongated, shortly plumose. 



