GRAMINEAE 33 



1. D. splcata (L. ) Greene. SPfKE-GRASS. Flowering onlms 5' high, 

 the sterile much taller, rigid and very leafy : spikelets clustered, 7-12, 

 ovate-lanceolate, S" long, 2^" wide, 8-12-flowered. — A. large patch of 

 the pistillate plants adventized in the railroad yards at ShefBeld. Our 

 form is var. stricta Scribn. May-June. 



46. DACTYLIS L. 



Spikelets 3-5-flowered in one-sided clusters in a dense panicle. Two 

 lower glumes empty, scarious-margined, mucronate-pointed, unequal, the 

 flowering 5-nerved, larger and short-awned or mucronate. Palet shorter, 

 2-keeled. 



1. D. glomerata L. Orchard Geass. A rough perennial 2°-4° 

 high : panicles 5'-8' long, its branches naked at base : spikelets i" long, 

 in dense clusters, 3-5-flowered. — Often planted and frequently found in 

 waste places, yards and meadows throughout. May-June. 



47. POA L. Meadow Grass. 

 Spikelets compressed, 2-10-flowered, paniculate. Glumes keeled, the 

 two empty ones shorter than the flowers, 1-3-nerved. Flowering glumes 

 scarious margined, 5-nerved, usually with a tuft of cobwebby hairs at 

 base, and the chief nerves pubescent. Palet shorter, 2-nerved. 



Annuals less than 12' high . 



Flowering glumes cobwebby at base. 1. P. Chapmaniana. 



Flowering glumes not cobwebby at base. 2. P. annua. 



Perennials, more than 12' high. 



Culms flattened. 3. P. compresaa. 



Culms terete, panicle branches erect. 4. P. nemoralis. 



Culms terete, panicle branches spreading. 

 Panicle branches 2-6 together. 

 Spikelets shorter than pedicels. 



Flowering glumes obscurely nerved. 5. P. flava. 



Flowering glumes strongly nerved. 



Flowering glumes silky-pubescent. 6. P. praiensis. 



Flowering glumes not silky-pubescent. 7. P. trimnlia. 

 Spikelets exceeding pedicels. 8. P. sylvestria. 



Panicle branches 1-2 together. 9. P. Wolfii. 



1. P. Chapmaniana Scribn. Southern Speae-grass. Tufted, 3'-] 2^ 

 high, erect : panicle l''-4'' long : spikelets 11" long, 3-7-flowered : flow- 

 ering glume \Y' Jong, cobwebby at base, rather obscurely 3-5-nervedr 

 the nerves pilose. — Common in sandy soil. April-May. 



2. P. annua L. Spear-geass. Like the last but ascending or spread- 

 ing : flowering glumes distinctly 5-nerved and not cobwebby at base . — 

 Sparingly adventized at Courtney. May-July. 



3. P. compressa L. WiEE GRASS. Culms 12'-20' high, flattened, 

 from long spreading rootstocks : panicle lJ'-3' long, 3"-6" wide: branches 

 ascending, spikelet- bearing throughout : spikelets IJ^'long, 3-10-flowered: 

 flowering glume 3-nerved, sparingly pubescent on the nerves toward the 

 Ijjige. — In waste places. Well distributed but not common. June-August. 



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