llilclicock — 'I'lic Grasses of I/azcaii 157 



22. GASTRIDIUM Beauv. 



Spikelets i-flowered, the racliilla di'^articulatiiig above the glumes, prolonged behind the 

 palca as a minute bristle: t^Iumes iinc(nial. somewhat enlarged or swollen at the base: lemma 

 much shorter than the glumes, hyaline, broad, truncate, awned or awnless : palea about as long 

 as the lemma, .\nnual grasses, with flat blades and pale, shining, spikelike panicles. 



I. Gastridium ventricosum (Gouan) Sclilnz & Thell. Mitt. I'.ot. Mus. I'niv. Zurich 58:39. 1913. 



Agrostis vcntricosa Gouan, Hort. Monsp. 39. pi. i. f. 2. 1762. 



Milium Icndigernm L. Sp. PI. ed. 2. 91. 1762. 



Gastridium australc Beauv. Ess. .\grost. 164. 1812. 



Gastridium leiidii;cruni Desv. Obs. .\ngers 48. 1818. • 



Culms about 30 cm. tall, smooth: panicle 5 to 8 cm. long, dense and spikelike; spikelets 

 5 to 6 mm. long, the glumes subulate-acuminate, the second shorter : lemma much shorter than 

 the glumes, subglobose, pul)escent at apex, the awn 5 mm. long ffig. 43 1. 



.\ \\ced in ]iastures; inti-dduced. Originally described from Europe. 

 Oalni: Scliofield Barracks, Hitclicock 14048. 

 Maui: Haleakala, Rock 8558; collector unknown fFaurie?] 1356. 



23. SPOROBOLUS R.Br. 



Spikelets I -flowered, the rachilla disarticulating alxjve the glumes: glumes awnless. 

 usually unequal, the second often as long as the spikelet : lemma membranaceous, i-nerved. 

 awnless: palea usually prominent and as long as the lemma or longer; seed free from the peri- 

 carp. .\nnual or perennial grasses, with small spikelets in open or contracted panicles. 



Plants with strong creeping rhizomes. T. S. virginicus. 



Plants tufted, without rhizomes. 



Inflorescence spikelike 2. S. elongatus. 



Inflorescence narrow but not spikelike 3- S. diander. 



1. Sporobolus virginicus ( L. ) Kunth, Rev. Gram. 1:67. 1829. 



Agrostis virginica L. Sp. PL 63. 1753. 



Plants perennial, with strong scaly creeping rhizomes: culms 10 to 30 cm. tall, glabrous, 

 pilose at the throat but the hairs sometimes deciduous : sheaths glabrous, mostly overlapping, the 

 blades conspicuously distichous, ascending or spreading, mostly 2 to 4 cm. long, sometimes longer. 

 2 to 3 mm. wide, flat or involute, firm, glabrous beneath, sometimes pilose on the upper surface; 

 panicle spikelike, tapering above and often also below, 2 to 5 cm. long : spikelets 2 to 2.5 mm. 

 long, pale: glumes unequal, scarcely nerved, acute, the first about two-thirds as long as the floret, 

 the second as long as the floret : lemma and palea acutish, the lemma smooth, faintly keeled and 

 scarcely nerved (fig. 45). 



Sandy beaches, tropics of Ixilh hemispheres. Originally described from 

 Virginia. 



Oahu: Kahuku, Hitchcock 13884. W ithout locality, Mann & Brigham 245. 

 Molokai: West end, Hitchcock 15130. 

 Maui: Sand hills, Wilkes Expl. Exped. 

 \\"ithout locality: Hillebrand; "Insulis Sandwich"', Faurie 1320. 



2. Sporobolus elongatus R. Br. Prodr. Fl. Xov. Holl. 170. 1810. 



Plants perennial, tufted ; culms erect, glabrous, somewhat compressed, 50 to 80 cm. tall ; 

 sheaths glabrous, sparingly pilose at the throat, shorter than the internodes, e.xposing one. 

 2, or rarely 3, nodes of the culm ; blades flat or usually involute, the lower elongate, 2 to 4 mm. 

 wide, ending in a fine point, glabrous beneath ; panicle spikelike, 10 to 20 cm. long. 3 mm. 



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