fertile lemma smooth and shiny. 



In marshes, seepage areas, about playa lakes, along sloughs, often forming large 

 colonies near water or in sporadic overflow areas, in Okla. (Waterfall), the w. 

 half of Tex., e. to n.-cen. Tex. and the Coastal Bend area, N. M. (Colfax and 

 Valencia cos.) and Ariz, (throughout the state), spring-fall; Mo. to Colo., s. to 

 Ark. and cen. Mex. 



14. Panicum hians Ell. Fig. 161. 



Tufted perennial; culms compressed, 2-6 dm. tall, mostly erect, sometimes 

 more or less decumbent or prostrate with erect branches; ligules minute; blades 

 5-15 cm. long, 1-5 mm. broad, flat or folded, pilose on the upper surface near 

 base; panicles 5-20 cm. long, usually loose and open, the primary branches few, 

 slender, distant, spreading or drooping, the branchlets borne on the upper half 

 or toward the ends only; spikelets in more or less secund clusters, short-pedicelled, 

 2.2-2.4 mm. long, 5-nerved, glabrous; palea of the sterile floret becoming enlarged 

 and indurate, expanding the spikelet to twice as thick as wide at maturity; fertile 

 lemma minutely papillose-roughened, relatively thin for this genus. 



Usually in low places, damp soil, in swamps, marshes, seepage areas, bogs, 

 sloughs and about ponds and lakes, Okla. (LeFlore, McCurtain, Atoka and John- 

 ston COS.) and e., s.e. and n.-cen. Tex. and Rio Grande Plains, rare w. to Llano 

 region, spring-fall; Coastal States, Va. to Tex.; also Mo., Ark., Okla. and Mex. 



15. Panicum anceps Michx. Fig. 154. 



Perennial from branching scaly rhizomes 2-4 mm. thick; culms 3-10 dm. long, 

 erect, compressed; sheaths keeled, glabrous to pilose or densely to sparsely villous 

 (especially at summit); ligule a scale 0.2-0.6 mm. long, firm; blades elongate, 

 4-12 mm. broad, pilose near base or often pubescent on both surfaces; panicles 

 15-40 cm. long, the branches ascending or spreading, slender, remote, bearing 

 short mostly appressed rather densely flowered branchlets; spikelets slightly oblique 

 to the pedicels, 2.4-3.8 mm. long, short-pedicelled, lanceolate, pointed, glabrous, 

 often gaping; sterile lemma 5- to 7-nerved; glumes and sterile lemma mostly 

 keeled; fertile lemma smooth and shiny and with a very minute tuft of thickish 

 hairs at apex. P. rhizomatum Hitchc. & Chase. 



Abundant in sandy well-drained usually forested uplands, in wet prairies, 

 swampy meadows, and on edge of streams and ponds, in Okla. (Pushmataha Co.) 

 and in e. and s.e. Tex., infrequent w. to n.-cen. Tex., late summer-fall; s.e. U.S. 

 w. to Kan., Okla. and Tex. 



16. Panicum rigidulum Nees. Fig. 154. 



Tufted perennial in dense clumps from a short multinoded crown, with numerous 

 short-leaved innovations at base; culms 5-10 dm. tall, erect, compressed; sheaths 

 keeled; ligules membranous, about 1 mm. long or less; blades erect, folded basally, 

 flat distally, 2-5 dm. long, 5-12 mm. broad, glabrous or sparsely pilose on the 

 upper side at the folded base; panicles terminal and axillary, 1-3 dm. long, a 

 fifth to nearly as broad as long, the long branches erect or spreading, naked at 

 base, the appressed to spreading densely flowered branchlets mostly borne on the 

 underside of the branches, the pedicels glabrous or bearing near the summit 1 or 

 several hairs; spikelets 1.8-2.8 mm. long, short-pedicelled, lanceolate, pointed, 

 glabrous; sterile lemma 5- to 7-nerved; glumes and sterile lemma mostly keeled; 

 fertile lemma and palea smooth and shiny, the fertile lemma sessile or rarely 

 with a very minute stipe and with a minute tuft of thickish hairs at apex. P. 

 agrostoides Spreng. and var. ramosius (Mohr) Fern., P. condensum Nash, P. 

 stipitatum Nash. 



317 



