156 Paniceae Panicum 



Culms and sheaths usually densely crisp-puberulent (sometimes sparsely so) ; 



blades generally less than 12 mm wide; spikelets 2.2-2.5 mm long 



44. P. Ashei, p. 172. 



Culms and sheaths generally nearly glabrous or only sparsely puberulent 



(not crisp-puberulent); blades or some of them usually more than 12 



mm wide; spikelets 2.5-3 mm long, generally about 2.7 mm long 



45. P. commiitahim, p. 173. 



1. DICHOTOMIFLORA 



Annual plants with smooth culms ; ligule membranous below, densely 

 ciliate above; spikelets glabrous; fruit smooth and shining. 



Spikelets 2-3.5 mm long, usually about 2.9 mm long (rarely a few as short as 2 mm), 

 acute; plants usually large and spreading, 50-100 cm long. . .1. P. dichotomiflorum. 



Spikelets 1.8-2.2 mm long, usually about 2 mm long, blunt; plants shorter and more 

 slender than the preceding la. P. dichotomiflorum var. puritanorum. 



1. Panicum dichotomiflorum Michx. Fall Panicum. Map 273. This 

 is an infrequent to frequent grass in all parts of the state, being much 

 more frequent in the southern part. It prefers a wet or moist soil, and 

 is found on the muddy shores of streams; in moist, open places in wood- 

 land, especially in old logging roads; and in moist places in stubblefields, 

 cornfields, waste places, and roadside ditches. 



Maine to Nebr., southw. to Fla. and Tex. 



la. Panicum dichotomiflorum var. puritanorum Svenson. (Rhodora 

 22: 154-155. 1920.) My only specimen of this variety is from a dried-up 

 pond about 3 miles southwest of Tefft, Jasper County, where it was closely 

 associated with Panicum spretum. The specimen I reported from Kosciusko 

 County I am now referring to Panicum Gattingeri Nash. 



Mass., Conn., L. I., and Ind. 



2. CAPILLARIA 



Annuals; sheaths papillose-hispid; ligules membranous, 1-3 mm long, 

 ciliate ; panicles many-flowered, mostly diffuse ; spikelets glabrous, pointed ; 

 first glume large, clasping ; fruit smooth and shining. 



Panicles drooping; spikelets 4.5-5 mm long. (See excluded species no. 80, p. 1030.) 



P. miliaceum. 



Panicles erect; spikelets not more than 4 mm long. 

 Spikelets mostly 3-3.5 mm long; second glume and sterile lemma 7-9-nerved; pulvini 



glabrous LP. flexile. 



Spikelets mostly 1.8-2.9 mm long; second glume and sterile lemma 5-nerved. 

 Pulvini of panicle hispid. 



Terminal panicles generally about half as long as the length of the whole plant 

 (except when crowded by other vegetation, when the terminal panicle may 

 be much shorter), usually large, about as wide as long, generally included at 

 the base; blades thickly papillose-hispid above and beneath, 5-15 mm wide; 



spikelets mostly 2-2.5 mm long 2. P. capillar e. 



Terminal panicles about a third the length of the entire plant, generally about 

 half as wide as long, usually long-exserted ; blades sparsely papillose- 

 pubescent on both surfaces, 2-6 (8) mm wide; spikelets 1.7-2 (2.2) mm 

 long 3. P. philadelphicum. 



