116 



POACEAE 



12. Panicum thermale Boland. 

 Hot Spring Panicum. Fig. 240. 



Panicum thermale Boland. Proc. Calif. Acad. 2: 181. 1862. 



Vernal form grayish green, densely tufted, velvety- 

 villous, 10-30 cm. tall; culms ascending or spreading; 

 nodes bearded; ligule about 3 mm. long; blades densely 

 villous on both surfaces ; spikelets about 2 mm. long, pu- 

 bescent ; autumnal form widely spreading, repeatedly 

 branching, forming a dense cushion. 



Wet saline soil mostly in vicinity of hot springs. Washington 

 (Granite Falls, Smith); Oregon (Rogue River, Nelson); California 

 (Sonoma County; vicinity of Lassen Peak); Yellowstone Park, and 

 northward June-Aug. Type locality: .Sonoma County, California. 



13. Panicum shastense Scribn. & ]\Jerr. 

 Shasta Panicum. Fig. 241. 



Panicum shastense Scribn. & Merr. U. S. Dept. Agr. Div. 

 Agrost. Circ. 35: 3. 1901. 



Vernal form 30-40 cm. tall, papillose-pilose 



throughout ; ligule 2-3 mm. long, sparse ; spikelets 



2.4-2.6 mm. long, papillose-pubescent ; autumnal 



form spreading, with geniculate nodes and elongate 



arched internodes, rather sparingly branchmg from 



the middle nodes. 



Meadows, Castle Crag, California, the type locality and 

 only known station (Greata, Hitchcock). 



14. Panicum scribnerianum Xash. 

 Scribner's Panicum. Fig. 242. 



Panicum scyibnerianum Nash, Bull. Torrey Club 22: 421. 1S95. 



\'ernal form erect, 30-60 ciu. tall, sheaths papillose- 

 hispid; ligule about 1 mm. long; blades 5-8 cm. long, 

 6-12 mm. wide, firm, rounded and ciliate at base, gla- 

 brous above, often pubescent beneath ; panicles 5-8 cm. 

 long; spikelets 3.2 mm. long, turgid, blunt, sparsely 

 hispid or nearly glabrous, strongly nerved ; autumnal 

 form branching from the middle and upper nodes, the 

 branches longer than the internodes, late in the season 

 producing crowded branchlets with ascending not great- 

 ly reduced blades and siuall, partially included panicles 

 from their upper nodes. 



Dry prairies and open ground, British Columbia to California 

 (Castle Crag, Hitchcock), and east to the Atlantic Coast._ June- 

 Aug. Type locality: Pennsylvania. This species was included 

 under P. scoparium in the Botany of California. 



9. ECHINOCHLOA P.eauv. Ess. Agrost. 53. pi. 11. f. 2. 1812. 



Spikelets, plano-convex, often stiffly hispid, subsessile, solitary or in irregular clusters 



on one side of the panicle branches; first glume about half the length of the spikelet, 



pointed; second glume and sterile lemma equal, pointed, mucronate, or the glume short- 



awned and the lemma long-awned, sometimes conspicuously so. inclosing a membranaceous 



