646 POACE^. 



Pedem. 2:259 (1785). H. Hystrix Roth, Catalect. 1:23 (1797), 

 H. puhescens Guss. Fl. Sic. Prod. 1 : 144 (1827). 



A smooth somewhat ghiucous and decumbent annual, 10-30 cm. 

 high. Sheaths about the length of the internodes, the upper one 

 inflated; ligule a mere ring; blades 2-6 cm. long, mostly involute. 

 Spike subterete, scarcely exserted, 2-4 cm. long, rachis breaking 

 when ripe, the joints 1 mm. long. Spikelets 1 cm, long, including 

 the stiff spreading awns; stipes of lateral spikelets 1.2 mm. long; 

 empty glumes all lanceolate, not ciliate, one of each lateral spikelet 

 a little broader. 



New Jersey (ballast-grounds), Scrihiier for U. S. Dept. Agri- 

 cul. 776; Oregon, Hoivell. 



Found along the coast in the Old World from Denmark to north 

 Africa. Introduced into North America. 



5. H. GussoxEANUM Pari. PI. Palerm. 244, obs. — Sicil. 

 Culms smooth, often decumbent, 20-30 cm. long. Leaf-blades 



flat, thin, finely pubescent, 2-5 cm. long, 2 mm. wide. Spikes 

 subterete, not included, 2-4 cm. long, 1 cm. diameter, breaking 

 when ripe, joints of the rachis 1 mm. long. Lateral spikelets 

 raised on stipes 1 mm. long; empty glumes mere bristles 12 mm. 

 long, excepting tliat the inner one to each lateral spikelet is twice 

 as wide as the others; central floret 6 mm. long; the floral glume 

 rough, oval when spread, 5-nerved, the awn 12 mm. long; palea as 

 long as its glume. Lateral florets small rudiments 2-4 mm. long, 

 including the awn. This is much like our specimens of H. mariti- 

 mum. When compared, //. Gussoneantim has the inner lateral 

 empty glumes half as long as wide, the rachis and base of glumes 

 less callous, the lateral florets smaller, softer and less developed. 

 Introduced into Oregon and California from Europe. 



6. H. MURixuM L. Sp. PI. 85 (1753). Wall-barley. Way 

 Bext. //. ciliatum Gilib. Exercit. 2:520. Zeocriton murinnm 

 Beauv. Agrost. 115 (1812). 11. leporinuin. Link, Linnsa, 9:133 

 (1835). 



A coarse decumbent annual, 30-60 cm. high. Leaves often 

 hairy ; sheaths about the length of tlie internodes; ligule very 

 short; blades 3-G cm. long. Spike 4-8 cm. long, often partially 



