64 POACEAE. 



Glumes not all subulate. 



Glumes of middle spikelet lanceolate. H. pusillum. 



Glumes of middle spikelet setaceous. H. gussoneanum. 



Glumes all alike, subulate. 

 Lateral florets long-awned. 



Awns 4—6 mm. long. H. jubatum. 



Awns 2-3 cm. long. H. caespitosum. 



Lateral florets not awned. 



Lateral florets neutral. H. nodosum. 



Lateral florets perfect. H. boreale. 



Hordeum murinum L.. Wall Barley. Stems 15-30 cm. tall; leaf blades 

 2-12 cm. long, 2-6 mm. wide; spikes 5-10 cm. long, thick; spikelets mostly in 

 threes, all stalked; both glumes of the central spikelet and the inner glume of 

 the lateral spikelets ciliate and flattened, bearing awns 20-25 mm. long; outer 

 glumes of lateral spikelets neither flattened nor ciliate; lemma scabrous at the 

 apex, long-awned. 



A weed in waste places. 



Hordeum pusillum Nutt. Stems 15-30 cm. high; spikes 3-8 cm. long; 

 both glumes of the central spikelet lanceolate and the inner ones of the lateral 

 spikelets dilated. 



Vancouver Island, British Columbia, Macoun, perhaps introduced. Com- 

 mon eastward. 



Hordeum gussoneanum Pari. Annual, glabrous, 10-30 cm. high; upper 

 sheath inflated; spike cylindrical, green, 2-5 cm. long; lemma 2-2.5 cm. long, 

 including the stiff straight awn. 



Sparingly introduced from Europe. 



Hordeum jubatum L. Squirrel Tail. Annual, tufted, erect, 30-60 cm. 

 high, glabrous or sometimes pubescent; leaf blades flat, becoming involute, 

 the sheaths shorter than the internodes; spike-like panicle pale green or yel- 

 lowish, 7-10 cm. long, readily breaking apart; central spikelet sessile, fertile, 

 the lateral ones peduncled and sterile; glumes all subulate, 3-6 cm. long. 



In salt marshes, not common. 



Hordeum caespitosum Scribn. Much like H. jubatum but the spikes 

 more slender and the awns shorter. 



Tacoma, Leckenby; perhaps introduced. 



Hordeum nodosum L. Annual or perennial, 30-90 cm. high, erect, leaf 

 blades flat or involute, the sheaths smooth or hairy; panicle spike-like, 3-8 cm. 

 long, narrow, usually flexuous, readily separating into joints; central spikelet 

 sessile, fertile, the lateral ones peduncled and sterile glumes all subulate, 2 cm. 

 or less in length. 



In moist meadows and along the seashore. 



Hordeum boreale Scribn. & J. G. Smith. Similar in every way to H. 

 nodosum except for the perfect lateral florets. 



In moist ground, Alaska to Oregon; perhaps only a form of H. nodosum. 



93. SITANION. 



Cespitose perennials, with spikes which readily break up into 

 segments; spikelets 2-3 at each joint of the rachis, rarely solitary, 

 1-5-nowered ; glumes subulate and entire, or lanceolate and bifid, 

 or parted into several long-awned lobes; lemmas lanceolate and 



