644 POACE^. 



do Joint of rachis 1 mm. long 4, 5 



d. Joint of rachis 3 mm. long 6 



e. Spikelets all fertile 7 



6. Spikelets with tlie lateral ones sterile 8 



1. H. jubatum L. Sp. PI. 85 (1753). Squireel-tail Grass. 

 Critesion gemciilatum Rafin. Jour. Phys. 89: 103 (1819). 



A smooth annual or biennial, 30—45 cm. high. Culms slender, 

 protruding 5-15 cm. above the sheath. Sheaths shorter than the 

 internodes; ligule 1 mm. long; blades of the upper leaves 4-7 cm. 

 long. Spike 4-7 cm. long, rachis very slender, breaking in pieces 

 when mature, each piece 1.3 mm. long. Lateral spikelets on pedi- 

 cels 1 mm. long, central one sessile ; empty glumes capillary, pale 

 straw-color or purple, 4-6 cm. long, recurved when mature and 

 dry; floral glume of tlie lateral florets small and sliort-awned, that 

 of the jierfect floret with an awn much like those of the empty 

 glumes. Grain elliptical, flat-concave, 3 mm. long. 



Vermont, P r ingle ; Michigan, ClarTc, Beal, Farwell ; Iowa, 

 Hitchcock; Illinois, B ebb, Beal 161; Minnesota, Arthur B 138; 

 Montana, Anderson 39 ; Colorado, Cassidy ; "Washington, Lake, 

 Sandberg 245 ; Oregon, Hotcell. 



On the seacoast and saline soil, about tlie Great Lakes and 

 elsewhere. 



Widely distributed. 



Were it not for the breaking of the spikes so freely, it would be 

 cultivated as an ornamental grass. 



2. H. Montanense Scribn. ined. 



Culms smooth, slender, about 80 cm. high. Leaf-blades flat, 

 scab rid, 10-15 cm. long, 4-7 mm. wide. Spike exserted, some- 

 times purplish, 6-8 cm. long, with internodes about 3 mm. long. 

 Empty glumes 10-20 mm. long, 0.3-0. 5 mm. wide. Central spike- 

 let 9 mm. long, the perfect floret bearing an awn 15-25 mm. long; 

 second floret merely an empty glume ; floral glume scabrid or shortly 

 hairy, o-uerved; palea a little shorter than its glume; florets of 

 lateral spikelets raised on a pedicel about 1 mm. above the central, 

 each consisting of floral glume, palea, lodicules, a rudimentary pistil 

 and sometimes a second floret reduced to a small empty glume. 



