Hitchcock — The Grasses of Hazvaii 157 



22. GASTRIDIUM Beauv. 



Spikelets i-flowered, the rachilla disarticulating above the glumes, prolonged behind the 

 palea as a minute bristle: glumes unequal, somewhat enlarged or swollen at the base; lemma 

 much shorter than the glumes, h3'aline, broad, truncate, awned or awnless ; palea about as long 

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



I. Gastridium ventricosum (Gouan) Schinz & Thell. Mitt. Bot. ]\Ius. L'niv. Zurich 58:39. 1913. 



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

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

 Gastridium australe Beauv. Ess. Agrost. 164. 1812. 

 Gastridium leiidigcrum Desv. Obs. Angers 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. pubescent at apex, the awn 5 mm. long (fig. 43). 



A weed in pastures ; introduced. Originalh' described from Europe. 

 Oahu: Schofield Barracks, Hitchcock 14048. 

 ^Nfaui; Haleakala, Rock 8558; collector unknown [Faurie?] 1356. 



23. SPOROBOLUS R. Br. 



Spikelets i-flowered, the rachilla disarticulating above 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. Annual or perennial grasses, with small spikelets in open or contracted panicles. 



Plants with strong creeping rhizomes i. 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, i -.Gj. 1829. 



Agrostis virginica L. Sp. PI. 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 both hemispheres. Originally described from 

 Virginia. 



Oahu: Kahuku, Hitchcock 13884. Without locality, Mann & Brigham 245. 

 Molokai: West end, Hitchcock 15130. 

 Maui: Sand hills, Wilkes Expl. Exped. 

 Without locality: Hillebrand; "Insulis Sandwich", Eaurie 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, exposing 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, 5 mm. 



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