60 GRAMINEAE. 



Annuals; panicle more or less lax; spikelets many (sometimes 70) -flowered, the 

 flowers densely imbricate; palea persistent after the bractlet and achene have 



fallen 28. Eragrostis. 



Perennials; panicle contracted and spikelike, dense or slightly interrupted, sil- 

 very shining; spikelets 2 to 7 (rarely only 1) -flowered 29. Koeleria. 



Bractlet 3 to 5-nerved. 



Perennials; uppermosl flower-enclosing bractlet enwrapping 1 to 3 smaller empty 



bractlets, which in ours are truncate-clavate 30. Melica. 



Bractlet 5 to many-nerved. 



Spikelets large, flattened, ovate, somewhat cordate at base; bractlet very obtuse, 



concave, becoming ventricose; annuals M. Briza. 



Spikelets not cordate, mostly smaller. 



Bractlet laterally compressed, mostly keeled, the margins or nerves below 

 clothed with cobwebby hairs, or pubescent, its lateral nerves arched, con- 

 verging above toward the mid-nerve 36. Poa. 



Bractlet rounded on the back, at least below, naked at the base, its lateral 

 nerves nearly parallel, scarcely or not at all converging. .37. Panicularia. 

 Hither bracts or bractlets owned, awn-pointed or mucronate. 



Palea with conspicuously toothed marginal wings on the keels; bractlet with a 

 straight, rigid awn; annuals of wet meadows, with weak stems, and pale 



greenish-yellow foliage 31. Pleuropogon. 



Palea without marginal wings on the keel. 



Panicle contracted and spikelike, dense or slightly interrupted, silvery-shining. 



29. Koeleria. 

 Panicle 1-sided, glomerate or interrupted; spikelets in dense ovoid 1-sided fas- 

 cicles 34. Dactylis. 



Panicle more or less lax, not dense and spikelike. 



Stigmas plainly arising at or near the apex of the ovary; ovary and achene in 

 most cases smooth; bractlet not notched or 2-lobed, usually awned or awn- 

 pointed 38. Festuca. 



Stigmas plainly arising below the apex of the ovary, on the anterior portion; 

 ovary and achene crowned by a little appendage or tuft of short hairs; 

 achene always adnate to the palea; bractlet usually distinctly notched or 

 shortly 2-lobed at the apex, with an awn between the notches.. 39. Bromus. 



26. ARUNDO L. 



Perennial reeds; stems tall, stout, erect. Leaf -blades broad, flat. Spikelets 

 2 to 6-flowered, in a dense and somewhat spreading panicle. Bracts somewhat 

 unequal, keeled, 3-nerved. Eachilla naked, jointed above the bracts and 

 between the flowers. Flowers crowded, all perfect or the upper staminate. 

 Bractlet slender, 2-toothed and with an awn or cuspidate point between the 

 teeth, clothed with long, silky hairs. Palea shorter, hyaline, pubescent on the 

 keels. Stamens 3. Ovary naked. (Latin arundo, a reed or cane.) 



1. A. donax L. Giant Reed. Rootstock very stout, creeping, tutted ; roots 

 stout, fibrous; stems in dense clumps, 10 to 20 ft. high, mostly with short, 

 Blender branches from the upper nodes, leafy throughout; leaves pale green; 

 sheath striate, bearded ami somewhat auriclod at the throat; ligule about 1 

 Line long, barely exserted, truncate, entire, uniform in width all around; 

 blade striate, mostly 2 to 3 in. wide, the uppermost l 1 ,. to 2 ft. long; spikelets 

 5 to 7 lines long, 2 to 3-flowered; bracts equaling the whole Bpikelet, lanceo- 

 late acuminate, entire, awnless, glabrous; bractlet acuminate; awn often twice 

 the length of the teeth. 



[ntroduced as an ornamental plant and occasionally met with as an escape. 

 It is not known to flower with us. Alameda Marshes. 



27. PHRAGMITES Trim 



Perennial water-reed. Stems tall, stout. Leaf-blades flat. Panicle large, 



much branched, feathery. Spikelets Bub-terete. Bracts short, unequal, mem- 



branaceous, keeled. Bachilla terminating in a rudimentary bractlet or point, 



elongated and jointed between the flowers, the joints clothed, except below 



