70 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



8. Poa nemoralis L. Sp. PI. 69. 1753. 



An erect, glabrous, tufted perennial, 20 to 60 cm. high, with narrow leaves, short 

 ligules, and lanceolate panicles 5 to 12 cm. long, the branches naked below, erect or 

 ascending, rarely spreading, 2 to 5 cm. long; spikelets 2 to 5-flowered, 3 to 4 mm. 

 long; lemmas 2 to 2.5 mm. long, faintly 5-nerved, somewhat webbed at the base and 

 silky-pubescent on the keel and marginal nerves below. 



Aleutian Islands and Alaska Peninsula, eastward to Newfoundland and southward; 

 also in Europe and Asia, 



Specimens examined: Unalaska, Coville & Kearney 1770, Piper 4770; Shumagin 

 Islands, Popof, Trclease <k Saunders 2975, Saunders in 1899; Kodiak Island, Trelease 

 6c Saunders 2940, Piper 4744, 4745, 4746, 4747, 4748, 4749, 4763; Kukak Bay, Coville 

 & Kearney 1500. 



The material here referred to Poa nemoralis is scarcely typical of that species, but 

 in the present state of our knowledge concerning this extremely difficult genus we have 

 considered it advisable so to refer it. 



9. Poa trivialis L. Sp. PL 67. 1753. 



An erect, usually slender, perennial, 30 to 90 cm. high, with flat leaves and open, 

 many-flowered panicles, 6 to 15 cm. long; sheaths slightly scabrous; ligule 4 to 6 mm. 

 long; culms usually rough below the panicle; spikelets 2 or 3-flowered, about 3 mm. 

 long; glumes very acute; lemmas prominently 5-nerved, silky-pubescent on the keel 

 below and with long, cobwebby hairs at the base. 



In meadows and along roadsides, Aleutian Islands and southeastern Alaska to New- 

 foundland and southward; also in Europe and Asia. 



Specimens examined: Atka Island, Turner 1198, common; Sitka, Wright 1583, in 

 drier places in shelter of young evergreen trees, Piper 4741; Wrangell, Evans 148, 

 abundant in cleared ground. 



10. Poa pratensis L. Sp. PI. 67. 1753. Kentucky bluegrass. 

 An erect, stoloniferous perennial, 30 to 120 cm. high, with narrow, flat leaves and 



more or less spreading, usually pyramidal, panicles, 5 to 20 cm. long; spikelets 3 to 

 5-flowered, 4 to 5 mm. long, exceeding their pedicels; glumes acute; lemmas 3 mm. 

 long, with abundant cobwebby hairs at the base, the keel and marginal nerves silky- 

 pubescent below, the intermediate nerves naked. 



Fields and meadows, from the Yukon valley southward and eastward to Newfound- 

 land; also in Europe and Asia. 



11. Poa rotundata Trin. Mem. Acad. St. Petersb. VI. Math. Phys. Nat. 1: 378. 1830. 

 A pale, slender, cespitose perennial, 30 to 70 cm. high, with elongated, linear, thin 



culm leaves and lanceolate few-flowered panicles 10 to 15 cm. long, the scabrous, 

 slender, somewhat flexuous, ascending branches naked below, flower-bearing above; 

 ligule 2 to 3 mm. long; culm leaves 10 to 15 cm. long; I to 1.5 mm. wide, plane, 

 glabrous; spikelets 4 to 5 mm. long, 3 or 4-flowered; glumes lanceolate, acuminate, 

 glabrous, the second about 0.5 mm. longer than the first, this 2.5 to 3 mm. in length; 

 lemmas lanceolate, acute, about 3 mm. long, glabrous, except on the keel and marginal 

 nerves, these silky-villous below but scarcely webbed. 



Upper Yukon, Aleutian Islands, and southeastern Alaska. 



Specimens examined: Unalaska, Mertens, cotype (from Herb. Acad. St. Petersb.); 

 Juneau, Cole in 1899, Coville cfe Kearney 2479; Eagle, Georgeson 28, a form with larger 

 spikelets than in the type. 



A valid species recognized by its lax habit, elongated, narrow leaves, and lax panicles. 

 The spikelets in anthesis are somewhat circular in outline, whence the name. 



12. Poa leptocoma Trin. Mem. Acad. St. Petersb. VI. Math. Phys. Nat. 1: 374. 1830. 

 Poa stenantha leptocoma Griseb. in Ledeb. Fl. Ross. 4: 372. 1853. 



A lax, pale green, glabrous perennial 30 to 50 cm. high, with thin, glabrous leaves 

 5 to 12 cm. long and 2 to 4 mm. wide, and lax, flexuous panicles 5 to 10 cm. long, the 



