GKASS FAMILY. 51 



Wet meadows and borders of streams: moist meadows Mission 

 Dolores, San Francisco, and Oakland Hills, Bolander in 1862; Presidio; 

 Mark West's Creek; Point Reyes. Apr.-July. 



2. D. elongata (Hook.) Munro. Slender Haik-grass. Peren- 

 nial; stems very slender and weak, 8 to 24 in. high or more, from a 

 dense tuft of bright green, fine, smooth, short, very narrow leaves; 

 ligule acute, 2 lines long; panicle very long and narrow; branches 

 several at a node, distant, mostly appressed, capillary, scabrous, 

 spikelet-bearing above the middle; pedicels somewhat clavate; spike- 

 lets many, IJ to 2 lines long; bracts linear-subulate, acuminate, nearly 

 equal, 3-nerved, green, exceeding the uppermost bractlet; bractlet 1 

 line long, smooth and shining, with a tuft of silky hairs at base, 

 irregularly 5-toothed or lacerate at apex; the lower and its flower on a 

 short callus; the upper upon a very hairy internode f as long as the 

 lower; awn arising ' from near the base of the bractlet and twice its 

 length, very slender and long exserted. — (Aira elongata Hook.) 



Moist places along the coast northward to Oregon. 



Var. ciliata Vasey. Stems 2 to 2| ft. high; ligule 4 lines long; 

 blades involute and softer; panicle often 12 in. long; awns longer than 

 in the type. — Lake Pilarcitos; Olema. June-Aug. 



Var. tenuis Vasey. Very small plant, 3 to 4 in. high, with soft, 

 hair-like, bright-green foliage; ligule long, white; panicle racemose, 

 1 to 2 in. long; branches appressed, with few spikelets. — Shady places 

 beside an intermittent foothill streamlet. Evergreen, Santa Clara Co. 

 May. 



3. D. calycina Presl. Tickle-grass. Annual; stems slender, 

 from a few inches to 2 ft. high, simple, often growing in dense masses, 

 rarely geniculate and sparingly branched below; leaves few, short, 

 narrow and ephemeral; ligule 1 to 1^ lines long, acuminate; panicle 

 simple, very loose and open or narrow, about J the length of the stem; 

 branches mostly in 3's below, in pairs or solitary above, bearing few 

 (about 5) spikelets upon the upper part, naked below; spikelets 2iJ to 

 4J lines long; lower flower on a short callus, its bractlet overlapping 

 that of the "upper flower; bractlet about 1 line long, hairy below, 

 shining above, 5-nerved; apex emarginate, with 4 minutely ciliate , 

 teeth; awn inserted below the middle, about 3 times as long as the 

 bractlet, light brown, twisted below and bent near the middle. — 

 (Aira danthonioides of Bot. Calif.) 



Common in the San Francisco Bay region and elsewhere in the 

 State, on poor, clayey soils: Napa Valley near St. Helena; Montezuma 

 Hills, Solano Co., Jepson; Kenwood; Santa Cruz. Apr.-June. 



19. TRISETUM Pers. Oat-grass. 

 Leaf-blades flat. Panicle usually open, narrow, more or less droop- 

 ing above; branches in whorls, slender, erect, spreading or drooping. 

 Spikelets 2 to 5-flowered. Bracts mostly shorter than the whole 

 spikelet, unequal, keeled, membranaceous; margins scarious; lower 

 bract 1 to 3, upper 3-nerved; rachilla extending beyond the insertion 



