GRASS FAMILY 157 



Refs. — POA SCABRELLA Benth. ; Vascy, Grasses U. S. 42. 1SS3 ; Abrams, Fl. Los Aug. 51. 

 1904. Atropis scahreUa Thurb. in Wats. Bot. Cal. 2: 310. 1880, type from Oakland, Bolander. 

 Poa orcutliana Vasey, W. Am. Sci. 3: 165. 1887, type from San Diego, Orcutt. P. limosa 

 Seribu. & Williams, U. S. Dept. Agr. Div. Agrost. Cire. 9: 5. 1899, type from Mono Lake, 

 Bolander. The species of this group re(|n-re careful monograplrc study. Poa secunda Presl 

 (Rcl. Haenk. 1: 271. 1830), from Chile appears to belong to this species, aud, if so, the name 

 must be taken up as has been done by Davy (Jepson, Fl. W. Mid. Cal. 67. 1901. See also, 

 Scribn. Rep. Mo. Bot. Gard. 10: 51. pi. 51. 1899). P. buckleijana Nash (BuU. Torr. Club 

 22: 465. 1895; P. tenuifolia Buckl. Proc. Acad. Phila. 1862: 96, 1S63, not A. Rich. 1851) is 

 probably also a synonym. 



17. P. sandbergii Vasey. Similar to P. scabrella; differing iu being smooth, 

 averaging lower and more slender, the panicle smaller, the blades short and 

 soft, often involute. 



Plains and dry or rock.y woods from Ventui'a and San Bernardino cos. north 

 to Britisli Coliiml)ia and east to Wyoming. Specimens intermediate between 

 this species and P. scabrella occur. 



Refs. — Poa sandbergii Vasey, Contr. Nat. Herb. 1: 276. 1893. Atropis tenuifolia Thurb. 

 in Wats. Bot. Cal. 2: 310. 1880, mainly as to description but the name is based on Poa 

 tenuifolia Buckl. 



18. P. nudata Scribn. Differs from P. scabrella in having a close and spike- 

 like panicle, nearly naked culms, and capillary blades. 



Only known from the type specimen, collected at Potrero. San Diego Co., in 

 1892, the collector^ unknown. 



Refs. — Poa nudata Scribn. U. S. Dept. Agr. Div. Agrost. Circ. 9: 1. 1899. P. ccipillaris 

 Scribn. U. S. Dept. Agr. Div. Agrost. Bull. 11: 51. 1898, not L., type from Potrero. 



If). P. tenerrima Scribn. Differs from P. scabrella in having a much more 

 open panicle, with spreading branches; blades capillary; ligule short. — Known 

 only from the type specimen, which was sent to Prof. Scribner from the Cali- 

 fornia Academy of Sciences, without data as to locality or collector. 



Ref. — Poa tenerrima Scribn. U. S. Dept. Agr. Div. Agrost. Circ. 9: 4. 1899. 



20. P. alcea Piper. Tufted perennial ; culms slender, 2 to 3 feet high, loose 

 and decumbent at base ; sheaths smooth or somewhat scabrous, loose and papery 

 at base: ligule long; blades flat, rather soft, more or less scabrous; panicle 

 loose and open, the branches 1 to 2 inches long, ascending; spikelets 3 to 4 

 lines long, tawny; glumes smooth, the second 2 lines long; lemmas about 2 

 lines long, pubemlent at base, the nerves not prominent. 



AVet rocks and rocky banks. ^lendocino Co. (Sherwood, Hitclicock 2714) ; also 

 in Oregon. A specimen from Palm Springs {Parish 6141) is tentatively referred 

 to this species but it is far out of the known range. 



Ref.— Poa alcea Piper, Bull. Torr. Club 32: 436. 1905. 



21. P. gracillima Vasey. Tufted perennial; culms 1 to 2 feet high, erect 

 from ustudly a ilccumljent base; sheaths smootli ; ligule II/2 lines long; blades 

 iiat or folded, lax, smooth, mostly basal ; panicle pyramidal, loose, rather open, 

 2 to 4 inches long, the branches in whorls, the lower 2 to 6, 1 to 3 inches long, 

 slender, spreading or sometimes reflexed, naked below; spikelets 2 to 3 lines 

 long: glumes smooth, the second IV^ to 2 lines long; lemmas about as long as 

 second glume, minutely scabrous, crisp-pubescent near base, especially on the 

 nerves. 



Rocky woods or gravelly soil, in the Sierra Nevada from Nevada Co, {Torrey 

 572) to Sequoia Nat. Park {nail & Bahcock 5540) ; Oregon to British Columbia, 

 Two specimens with smooth lemmas are referred here, Nacimiento River, j\Ion- 

 terey Co,, Davy 7673 and El>betts Pass, Brewer 2077. The former is out of 

 range and may belong to a different species. 



