GRASS FAMILY 



149 



10. A. paUcns. 



11. A. dicgoensis. 



Tuft of hairs minute or wanting. 

 Panicle spikelike. 

 Panicle open. 

 Plants tufted, not producing rhizomes or only short ones. 



Panicle narrow, usually a part of the lower branches spikelet-bearing from the base. 

 Panicle strict, the branches short and appressed; plant low and cespitose. 



12. A. brcviciilmis. 



Panicle narrow or somewhat open, not strict. 



Panicle short, 2-4 cm. long; a dwarf plant of high altitudes; lemma awnless. 



13. A. rossae. 



Panicle usually elongate; a usually taller plant of low or intermediate altitudes; lemma 

 owned or awnless. 14. A. e.varata. 



Panicle open, sometimes diffusely spreading; usually no short branches in the lower whorls 



of branches. i - ^ i ;;•• 



Awn attached near base of lemma; panicle diffuse. Is. A. hoivelni. 



Awn, if present, attached at or above the middle of the lemma. 



Panicle very diffuse, the branches capillary, spikelet-bearing toward the tips. 



Panicle open but not diffuse. 

 Lemma awned. 



Lemma awnless. 



Plants producing short rhizomes; leaves mostly basal. 

 Plants not producing rhizomes. 



Plants delicate, 10-30 cm. tall. 



Plants slender, usually over 40 cm. tall. 



16. A. hicmalis. 



17. A. longUigula. 



18. A. let' id a. 



19. A. idahooisis. 



20. A. orcgonensis. 



1. Agrostis retrofracta W'ilkl. 

 Hairy-rtowered Bent-grass. Fig. 328. 



Agrostis retrofracta Willd. Enum. PI. 1: 94. 1809. 

 Agrostis forstcri Roem. & Schult. Syst. Veg. 2: 359. 1817. 

 Calamagrostis forsteri Steud. Nom. Bot. ed. 2. 1: 250. 1840. 

 Calamagrostis retrofracta Link; Steud. Nom. Bot. ed. 2. 1: 

 251. 1840. 



Perennial ; culms tufted, erect or decumbent at 

 base, 20-60 cm. tall ; sheaths smooth ; ligule of 

 culm leaves 3-5 mm. long; blades flat, scabrous, 1-2 

 mm. wide; panicle diffuse, 15-30 cm. long, the 

 branches in distant whorls, capillary, reflexed at 

 maturit}', divided above the middle ; glumes acumi- 

 nate, 3 mm. long; lemma shorter than the glurnes, 

 thin, pubescent, short-bearded on the callus, bearing 

 about the middle of the back a slender geniculate 

 and twisted awn exserted about the length of the 

 glumes ; palea narrow, nearly as long as the lemma ; 

 rudiment slender, pilose, as long as the lemma. 



Introduced 15 miles south of Stockton, California (Ball). 

 A common Australasian species. Type locality: Australia. 



2. Agrostis aequivalvis Trin. 

 Northern Bent-grass. Fig. 329. 



Agrostis canina aequivalvis Trin. in Bong. Mem. Acad. S.t. Petersb. 

 VL Math. Phys. Nat. 2: 171. 1832. 



Agrostis aequivalvis Trin. Mem. Acad. St. Petersb. VI. Sci. Nat. 

 4': 362. 1841. 



Deyeuxia aequivalvis Benth. Journ. Linn. Soc. Bot. 19: 91. 1881. 



Culms tufted, slender, smooth, 30-60 cm. tall ; ligule 

 2 mm. long ; blades narrow, upright, those of the culm 1 or 

 2, appressed, 4—6 cm. long. 1 mm. wide, somewhat scabrous ; 

 panicle open, 5-15 cm. long, the branches slender, soinewhat 

 scabrous ; spikelets about 3 mm. long, usually purplish ; 

 glumes equal, sharp-pointed, minutely scabrous below the 

 tip of the keel ; lemma obtuse, about as long as the glumes ; 

 palea nearly as long as the glumes ; rudiment minutely pu- 

 bescent, one-fifth to one-half the length of the spikelet. 



Wet meadows and moist places in the Hudsonian Zone; Alaska 

 to Oregon, rare within our limits. July. Type locality: Sitka. 



