CRASS FAMILY. 59 



25. BECKMANNIA Host. 



Leaf -blades flat. Panicle long, narrow, erect, dense, composed of several 

 approximate, erect racemed spikes. Spikelets crowded in 2 rows on the 2 

 Lower sides of the sub-triangular panicle-branches, imbricate, compressed, 2 

 (or by abortion) 1 -flowered, 1 to 1% linos long. Bracts broadly inflated and 

 somewhat boat-shaped, laterally compressed, sub-equal, obtuse or abruptly 

 pointed; margins scarious. Bractlet narrow, concave-keeled, membranaceous, 

 5-nerved ; palea hyaline, 2-keeled, nearly as long as the bractlet. Stamens 3. 

 (J. Beckmann, 1739-1811, the author of a "Lexicon Botanicum. ") 



1. B. erucaeformis (L.) Host. SLOUGH-GRASS. Stems 2 to 3 ft. high, 

 stout ish, strict, solitary or somewhat tufted, erect from a slightly decum- 

 bent base, leafy; sheaths slightly rough; ligule elongated; blades 4 to 8 in. 

 long, 3 to 4 lines wide, roughish; panicle 8 to 12 in. long; branches solitary 

 or in twos or threes, sometimes again shortly branched, densely clothed with 

 spikelets in 2. rows; spikelets about 1% lines long, nearly orbicular or broadly 

 obovate; bracts with 3 principal nerves, and some transverse ones, dark 

 green on the keel, paler and somewhat wrinkled transversely; bractlet pointed, 

 the point often exserted. 



Sloughs, borders of streams and wet bottom lands in mountain regions from 

 Santa Clara Co. northward to Willits. Apr.-July. Somewhat resembling a 

 Panicum. 



Tribe 7. Festuceae. Fescue Tribe. 



Inflorescence paniculate or racemose, the racemes sometimes almost spicate 

 on account of the very short pedicels of the spikelets. Spikelets 2 to many- 

 flowered (rarely 1-flowered in Melica, Koeleria, Festuca and Lamarckia) ; 

 flowers perfect or the uppermost imperfect (the lowest imperfect in Phrag- 

 mites) ; in Lamarckia one spikelet at each node is perfect, the others being 

 sterile; in Distichlis, some species of Poa and sometimes in Phragmites the 

 flowers are dioecious or polygamo-dioecious. Bracts rarely reaching the apex 

 of the nearest bractlet. Bractlet in ours entire or 2-toothed or 2-cleft, awn- 

 less or with 1 (in ours never 2 to 5) awns; awn straight, terminal at the apex 

 or from between the teeth, never dorsal nor bent and twisted as in Aveneae 

 and Agrostideae. Palea 2-keeled. 



A. Rachilla or bractlet, at least that of the perfect flower, clothed with long, erect 

 hairs which envelop the latter; bractlet (in ours) thin-membranaceous or hyaline, 3- 

 nerved; tall, reed-like grasses. 



Bractlet hairy; rachilla naked 26. Arundo. 



Bractlet naked; rachilla hairy 27. Phragmitks. 



B. Rachilla and bractlet naked, or if hairy the hairs much shorter than the bracts 

 and bractlet; stigmas (in ours) plumose, comparatively short, either sessile or raised on 

 a short style protruding from the sides of the bractlet. 



Spikelets of two kinds at each node, very dissimilar in form, one perfect and 1 to 3- 

 flowered; the others sterile and composed of many empty bractlets. 

 Perfect spikelets 1-flowered, the sterile consisting of about 10 empty bractlets which 



are obtuse 35. Lamarckia. 



Spikelets alike in form though sometimes dioecious. 

 Flowers dioecious; rootstock perennial. 



Spikelets 8 to 16-flowered, rootstock very stout and creeping, scaly; panicle dense, 



ovoid; grasses of salt-marshes or alkali soils 32. Distichlis. 



Spikelets 2 to 6-flowered; rootstock tufted or if creeping then long and slender.... 



36. Poa. 

 Flowers all perfect, or perfect and imperfect in the same spikelet. 

 Both bracts anil bractlets awnless. 

 Bractlet 1 to 3-nerved. 



