MANUAL OF THE GRASSES OF THE UNITED STATES 



685 



125. Panicum dichotomiflorum 



Michx. Fall panicum. (Fig. 1034.) 

 Culms ascending or spreading from 

 a geniculate base, 50 to 100 cm. long, 

 or in robust specimens as much as 



2 m. long ; ligule a dense ring of white 

 hairs 1 to 2 mm. long; blades sca- 

 berulous and sometimes sparsely pi- 

 lose on the upper surface, 10 to 50 

 cm. long, 3 to 20 mm. wide, the 

 white midrib usually prominent ; pan- 

 icles terminal and axillary, mostly 

 included at base, 10 to 40 cm. long 

 or more, the main branches ascending; 

 spikelets narrowly oblong-ovate, 2 to 



3 mm., usually about 2.5 mm., long, 

 acute. O — Moist ground, along 

 streams, and a weed in waste places 

 and cultivated soil, Nova Scotia and 



Figure 1032. — Panicum arizonicum. Two views of 

 spikelet, and floret, X 10. (Palmer 159, Mexico.) 



Figure 1033. — Panicum texanum. Panicle, X 1; two views of spikelet, and 

 floret, X 10. (Hitchcock 3187, Tex.) 





Jiff 



Maine to Minnesota, south to Flor- 

 ida and Texas, occasionally intro- 

 duced farther west ; here and there in 

 the West Indies. Panicum dichoto- 

 miflorum var. puritanorum Sven- 

 son. Differing in the shorter, more 

 slender culms and looser panicles and 

 in the rather less-pointed spikelets 

 about 2 mm. long. Inter grades with 

 the species. O — Wet sandy or 

 boggy shores of ponds, Massachusetts, 

 Connecticut, Long Island; Indiana. 

 126. Panicum bartowense Scribn. 

 and Merr. (Fig. 1035.) Resembling 



P. dichotomiflorum, mostly larger; 

 culms erect, simple or sparingly 

 branched, as much as 2 m. tall and 

 7 mm. thick; sheaths papillose-hispid; 

 ligule 2 to 3 mm. long. O — Low 

 ground, often in shallow water, Flor- 

 ida; Bahamas; Cuba, Jamaica. 



127. Panicum lacustre Hitchc. and 

 Ekman. (Fig. 1036.) Aquatic or 

 terrestrial perennial; culms nearly 

 simple, those of terrestrial plants 

 erect, about 1 m. tall, with short 

 innovations with pilose sheaths and 

 flat blades, 1 to 10 cm. long, 2 to 4 



