100 GBAMINEAE 



1. A. bromoides II.B.K. Annual; culms much-branched at the base, 4 to 

 12 inches long, erect or often spreading or prostrate; blades 1 to 2 inches long, 

 narrow, usually involute ; panicle narrow, rather dense, 2 to 3 inches long, the 

 branches short, fascicled ; glumes unequal, smooth except the keel of the first, 

 1-nerved, the first 2y 2 to 3 lines long, acutish, the second '3 l /2 to 4 lines long, 

 obtuse or slightly mucronate; lemma 4 to 5 lines long, smooth except upper 

 portion of keel, the callus with a dense tuft of short hairs, the apex scarcely 

 narrowed; awns equal, finally spreading, about 5 lines long, or the lateral 

 sometimes shorter. 



Open ground, southern California to New Mexico and south through Mexico. 



Loes. San Luis Obispo, Jones 3245; Funoral Mts., Coville 4" Funston 259; The Needles, 

 Jones 3788; western edge Colorado Desert, Wilder 1080; Colorado River, Riverside Co., Jlall 

 5963; Coachella, Hall 5797; San Diego, Brandegee 832; Santa Catalina Island, Brandegee. 



Refs. ABISTIDA BROMOIDES H. B. K. Nov. Gen. & Sp. 1: 122. 1816; Thurb. in Wats. Bot. 

 Cal. 2: 289. 1880. A. americana L. var. bromoides Seribn. & Merr. U. S. Dept. Agr. Div. 

 Agrost. Circ. 32:5. 1901 (under a misapprehension as to the identity of A. americana L., 

 which is Bouteloua americana (L.) Seribn. and not A. dispersa Trin. & Rupr.) ; Abrams Fl. 

 Los Ang. 28. 1904. 



2. A. oligantha Michx. Annual ; culms erect, branched at base and all the 

 nodes, 1 to 2 feet high, often woolly at the very base; blades a line wide or 

 less, usually involute, as much as 6 inches long, sparingly pilose at base, the 

 prophyllum often conspicuous at base of branches; panicles narrow, loosely 

 few-flowered, bearing a few scattered large appressed short-pediceled spike- 

 lets; glumes about 1 inch long, slightly unequal, long-awned from a bifid apex, 

 the first strongly 7-nerved ; lemma a little shorter than the glumes, the gradu- 

 alty narrowed neck scaberulous, the callus rather minutely pubescent; awns 

 about equal, widely spreading, 2 to 3 inches long. 



A native of the Southeastern States, probably introduced in California. Chico, 

 Copeland 3488 ; Mokelumne region, Sacramento Valley, Fowler; Merced Falls, 

 Kelsey. 



Ref. ABISTIDA OLIGANTHA Michx. Fl. Bor. Am. 1: 41. 1803. 



3. A. palmeri Vasey. Perennial; culms cespitose, erect, 1 to 2 feet high; 

 blades involute. 2 to 4 inches long, a pilose ring at base extending around the 

 collar; panicle about 1/2 the entire length of the culm, loose; branches mostly 

 in pairs, stiffly ascending or spreading, spikelet-bearing toward the extremi- 

 ties; glumes acuminate, nearly equal, about 5 lines long, scabrous on the keel 

 and the first also on the obscure lateral pair of nerves ; lemma 5 to 6 lines long, 

 smooth except the densely pubescent callus, gradually narrowed above into a 

 twisted neck; awns unequal, the central spreading, about 4 lines long, the 

 lateral erect, 1 to 2 lines long. 



San Diego Co. (Hanson's Mt.. Orcutf) Arizona and northern Mexico. 

 Refs. ARISTIDA PALMERI Vasey, Bull. Torr. Club 10: 42. 1883. A. lemmoni Seribn. in 

 Britt. & Kearn. Trans. N. Y. Acad. Sci. 14: 23. 1894. 



4. A. divaricata Humb. & Bonpl. Perennial ; culms cespitose, erect, 1 to 2 

 feet high ; blades involute, as much as 6 inches long ; panicle usually more 

 than y 2 the length of the entire plant; branches distant, mostly in pairs, 

 divaricately spreading, spikelet-bearing toward the ends ; glumes nearly equal, 

 5 to 6 lines long, 1-nerved, short-awned, the first scabrous on the keel; lemma 

 about 5 lines long, scabrous toward the scarcely narrowed apex; awns about 

 equal, 6 to 10 lines long, somewhat spreading. 



Southern California to Texas and south on the Mexican plateau. 



