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MISC. PUBLICATION 200, U. S. DEPT. OF AGRICULTURE 



lemma; rachilla slender, pilose, from 

 half to as long as the lemma. % 

 (A. retrofracta Willd.) — Introduced in 

 central California (15 miles south of 

 Stockton), Texas (Kent), and Ohio 

 (Painesville) ; common in Hawaiian 

 Islands and Polynesia. 



Figuke 461. — Agrostis thurberiana. Panicle, X 1; 

 glumes and floret, X 5. (Type.) 



Figure 462. — Agrostis aequivalvis. Panicle, X 1; 

 glumes and floret, X 5. (Howell 1712, Alaska.) 



2. Agrostis thurberiana Hitchc. 

 Thurber bent. (Fig. 461.) Culms 

 slender, in small tufts, erect, 20 to 40 

 cm. tall; leaves somewhat crowded at 

 base, the blades about 2 mm. wide; 

 panicle rather narrow, lax, more or 

 less drooping, 5 to 7 cm. long; spike- 

 lets green, pale, or purple, 2 mm. 

 long; lemma nearly as long as the 

 glumes, the palea about two-thirds as 

 long; rachilla hairy, 0.3 mm. long. 

 91 — Bogs and moist places, at me- 

 dium and upper altitudes, Colorado 



to British Columbia and south in the 

 Sierras to central California. 



3. Agrostis aequivalvis (Trin.) 

 Trin. (Fig. 462.) Similar to A. thurber- 

 iana; culms on the average taller, 

 blades longer; panicle usually purple, 

 5 to 15 cm. long; spikelets about 3 to 

 4.5 mm. long; palea nearly as long as 

 the lemma; rachilia minutely pubes- 

 cent, one-fifth to half as long as the 

 lemma. % — Wet meadows and 

 bogs, Alaska, southward (rare) in the 

 Cascade Mountains to Oregon. 



4. Agrostis semiverticillata 

 (Forsk.) C. Christ. Water bent. 

 (Fig. 463.) Culms usually decumbent 

 at base, sometimes with long creeping 

 and rooting stolons; blades firm, 

 mostly relatively short and broad, but 

 in luxuriant specimens elongate; pan- 

 icle contracted, 3 to 10 cm. long, 

 densely flowered, lobed, with short 

 verticillate branches, especially at 

 base, the branches spikelet-bearing 

 from the base; spikelets usually falling 

 entire; glumes equal, narrowed to an 

 obtuse tip, scabrous on back and keel, 

 2 mm. long; lemma 1 mm. long, awn- 

 less, truncate and toothed at apex; 

 palea nearly as long as the lem- 

 ma. % (A.verticillataYill.) — Moist 

 ground at low altitudes, especially 

 along irrigation ditches (in irrigated 

 regions), Texas to California, north to 

 Utah and Washington; on ballast at 

 some Atlantic ports. Introduced in 

 America, south to Argentina; warmer 

 parts of the Eastern Hemisphere. 



Figure 463. — Agrostis semiver- 

 ticillata. Panicle, X 1; glumes 

 and floret, X 5. (Schoenfeldt 

 3159, Calif.) 



5. Agrostis stolonifera L. (Fig. 

 464.) Culms ascending from a spread- 



