MANUAL OF THE GRASSES OF THE UNITED STATES 



171 



blades mostly less than 10 cm. long, 2 

 to 8 mm. wide; panicle erect, 10 to 20 

 cm. long, oblong or pyramidal, yellow 

 to brown, the branches spreading in 

 somewhat distant whorls; spikelets 

 short-pediceled, about 3 mm. long; 

 glumes about 1.5 and 2 mm. long; 

 lemmas 2.5 to 3 mm. long. 9[ 

 — Mountain meadows, around springs 

 and along streams, Newfoundland 

 and Labrador to Alberta, south 

 through Wisconsin, North Dakota, 

 South Dakota, and eastern Oregon to 

 northern Arizona; Eurasia. Some- 

 times 1-flowered spikelets occur in 

 panicles with 2-flowered ones. 



Cutandia memphitica (Spreng.) 

 Richt. Low annual; blades flat; pan- 

 icle few-flowered; spikelets on short 

 pedicels, finally divergent on the zig- 

 zag branches. O —San Bernardino 

 Mountains, Calif.; introduced from 

 the Mediterranean region. 



16. MOLINIA Schrank 



Spikelets 2- to 4-flowered, the flor- 

 ets distant, the rachilla disarticulat- 

 ing above the glumes, slender, pro- 

 longed beyond the upper floret and 

 bearing a rudimentary floret; glumes 

 somewhat unequal, acute, shorter 

 than the first lemma, 1-nerved; lem- 

 mas membranaceous, narrowed to an 

 obtuse point, 3-nerved; palea bowed 

 out below, equaling or slightly exceed- 

 ing the lemma. Slender tufted peren- 

 nials, with flat blades and narrow, 

 rather open panicles. Type species, 

 Molinia caerulea. Named for J. I. 

 Molina. 



1. Molinia caerulea (L.) Moench. 

 (Fig. 233.) Culms erect, 50 to 100 cm. 

 tall; blades 2 to 7 mm. wide, erect, 

 tapering to a fine point; panicle 10 to 

 20 cm. long, purplish, the branches 

 ascending, rather densely flowered, 

 mostly floriferous to the base; spike- 

 lets short-pediceled, 4 to 7 mm. long; 

 lemmas about 3 mm. long. % — 

 Meadows and fields, introduced in a 

 few localities, Maine to Pennsylvania; 

 Eurasia. 



17. DIARRHfiNA Beauv. 



(Diarina Raf.) 



Spikelets few-flowered, the rachilla 

 disarticulating above the glumes and 

 between the florets; glumes unequal, 

 acute, shorter than the lemmas, the 

 first 1-nerved, the second 3- to 5- 

 nerved; lemmas chartaceous, pointed, 

 3-nerved, the nerves converging in the 

 point, the upper floret reduced; palea 

 chartaceous, obtuse, at maturity the 

 lemma and palea widely spread by the 

 large turgid beaked caryopsis with 

 hard shining pericarp; stamens 2 or 3. 

 Perennials, with slender rhizomes, 

 broadly linear, flat blades, long- 

 tapering below, and narrow, few- 

 flowered panicles. Type species, Diar- 

 rhena americana. Name from Greek 

 dis, twice, and arren, male, alluding to 

 the two stamens. 



1. Diarrhena americana Beauv. 

 (Fig. 234.) Culms slender, about 1 

 m.tall, arched-1 eaning, leaves approx- 

 imate below the middle of the culm; 

 sheaths pubescent toward the sum- 

 mit; blades elongate, 1 to 2 cm. wide, 

 scabrous to pubescent beneath; pan- 

 icle long-exserted, drooping, 10 to 

 30 cm. long, the branches few, ap- 

 pressed, the lower distant; spikelets 

 10 to 18 mm. long, at first narrow, 

 the florets expanded at maturity; 

 lemmas 6 to 10 mm. long. % 

 (Diarina festucoides Raf.) — Rich or 

 moist woods, Virginia to Michigan 

 and South Dakota, south to Ten- 

 nessee, Arkansas, Oklahoma, and 

 eastern Texas. 



18. DISSANTHfiLIUM Trin. 



Spikelets mostly 2-flowered, the 

 rachilla slender, disarticulating above 

 the glumes and between the florets; 

 glumes firm, nearly equal, acuminate, 

 much longer than the lower floret, 

 mostly exceeding all the florets, the 

 first 1-nerved, the second 3-nerved; 

 lemmas strongly compressed, oval or 

 elliptic, acute, 3-nerved, the lateral 

 nerves near the margin; palea some- 



