64 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



and has been also by recent authors. Deschampsia brachyphylla Nash is distinct from 

 the plant described as Deschampsia brevi/olia by Robert Brown, which belongs to 

 Deschampsia arctica (Spreng.) Merrill. 



12. TBISETUM Pers. 



Trisetum Pers. Syn. PI. 1: 97. 1805. 



Spikelets 2-flowered or rarely 3 to 5-flowered; rachilla hairy or naked, articulated 

 above the glumes and between the florets, produced beyond the upper floret as a 

 (usually) hairy bristle; glumes 2, awnless, carinate, usually unequal; lemmas sub- 

 hyaline, carinate, cleft or 2-toothed at the apex, the teeth sometimes produced into 

 slender awns, bearing between them, or a little below the cleft, a straight or usually 

 twisted and geniculate awn. Oespitose perennials with flat leaves and dense spike- 

 like or loose and open panicles. 



Inflorescence a lax, open, few-flowered panicle 1. T. cernuum. 



Inflorescence a densely flowered spike-like panicle. 



Plants glabrous or nearly so 2. T. spicatum. 



Plants densely soft-pubescent throughout. 



Spikelets about 5 mm. long 2a. T. spicatum 



molle. 

 Spikelets about 7 mm. long 3. T. alaskanum. 



1. Trisetum cernuum Trin. Mem. Acad. St. Petersb. VI. Math. Phys. Nat. 1: 61, 



1830. 



A slender perennial (SO to 100 cm. high with rather broad, flat leaves and loosely 

 flowered, nodding panicles 12 to 20 cm. long; spikelets 6 to 8 mm. long, 2 to 4-flowered; 

 lemmas with a few hairs at the base, scabrous, cleft at the apex and bearing a slender 

 awn 6 to 10 mm. long. 



In damp soil and thickets, from Yakutat Bay to the southeastern boundary and 

 southward to Montana, Idaho, and northern California. 



Alaska specimens: Yakutat, Piper 4650; Latouche, Piper 4648; Juneau, Coville & 

 Kearney 2512; Yes Bay, Behm Canal, Howell 1716; Sitka, Piper 4649. 



2. Trisetum spicatum (L.) Richter, PI. Eur. 1: 59. 1890. 

 Aira spicata L. Sp. PI. 64. 1753, not A. spicata L. op. cit. 63. 

 ^4ira subspicata L. Syst. Nat. ed. 10. 873. 1759. 



A tufted, nearly glabrous perennial, 10 to 60 cm. high, with densely flowered, spike- 

 like, usually purplish panicles 3 to 10 cm. long; spikelets 2 or 3-flowered, usually about 

 5 mm. long, the lemmas slightly exserted, each bearing a scabrous, usually flexuons 

 awn about as long as the lemma. 



In rocky places, Seward Peninsula to the Aleutian Islands and southeastern Alaska, 

 eastward to Labrador and southward to North Carolina, New Mexico, and California; 

 also in Europe, Asia, and Australia. 



Specimens examined: Port Clarence, Walpole 1790, 1714, 1991; Unalaska, Har- 

 rington in 1871-72; Kukak Bay, Trelease & Saunders 2934; Muir Glacier, Trelease dc 

 Saunders 2932. 



An extremely variable and widely distributed species presenting many puzzling 

 forms. 



2a. Trisetum spicatum molle (Michx.) 



Avena mollis Michx. Fl. Bor. Amer. 1: 72. 1803. 



Trisetum molle Kunth, Rev. Gram. 1: 101. 1829. 



A densely tufted form with habit and spikelet characters of the species, but differing 

 in its densely pubescent culms, sheaths, and leaves. 



Throughout Alaska and the same general range as the species. 



