974 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
RANGE: Temperate and warmer regions of the Old World, adventive from northern 
United States to Mexico. 
HERBARIUM SPECIMENS FROM MEXIco: 
Mexico: Tlalnepantla, wet meadow, Rose, Painter & Rose 8384. Federal Dis- 
trict, Tacubaya, Bourgeau 221. 
3. Phalaris canariensis L. Sp. Pl. 54. 1753. CANARY GRASS. 
Type locality, ‘‘Canariis.”’ 
Rance: Warmer parts of the Old World, introduced in the Western Hemisphere. 
HERBARIUM SPECIMENS FROM MEXICco: 
SrvaLoa: Rosario, Rose in 1897. 
Nuevo Lrdn: Monterey, fields, Dodge in 1891. 
Freperat District: San Angel, Orcutt 3695. 
58. SAVASTANA Schrank, Baier. Fl. 1: 100, 337. 1789. 
1. Savastana mexicana (Rupr.) Beal, Grasses N. Amer, 2: 187. 1896. 
Ataxia mexicana Rupr.; Fourn. Mex. Pl. 2: 71. 1886. 
Type locality, “Cerro San Felipe,’’ Oaxaca, the type specimen collected by Galeotti 
(no, 5756). 
Rance: Known only from the type locality. 
HERBARIUM SPECIMENS: 
Oaxaca: Sierra de San Felipe, dry ridges under pines, Pringle 4700; Smith 940; 
Conzatti & Gonzdlez 420. Summit of Zempoaltepec, Nelson 624. 
59. ARISTIDA L. Sp. Pl. 82. 1753. 
KEY TO THE SPECIES, 
Lateral awns short or none. 
Plants annual; awn not twisted, flexuous; branchlets sparsely 
long-pilose ...... 2.22.2 022. eee ee eee eee eee eee ee 1. A. jorullensis. 
Plants perennial. 
Awns twisted at neck............. 2.22.02... e eee eee 2. A. schiedeana. 
Awns not twisted. 
Awns recurved........ oe tenn ee wens c cece nec eeeces 3. A, purpusiana. - 
Awns straight or fexuous..-.-.....2-..2.....2.... 4. A. scabra. 
Lateral awns at least half as long as the central one. 
Neck of fruit jointed at base, long and slender, twisted. 
Plants perennial; glumes unequal, awnless ............. 6. A. californica. 
Plants annual; glumes equal, awn-pointed.............. 5. A. tuberculosa. 
Neck of fruit not jointed. 
Plants annual, mostly low and spreading; panicle narrow 
and rather dense... ....-.-..---------------000- 7. A. bromoides. 
Plants perennial. 
Culms and sheaths lanate-pubescent .........-.-.. 8. A. lanuginosa. 
Culms glaprous. 
Neck of awns twisted. 
Branches of panicle long, naked below. 
Paniclebranchesstiffly divergent; blades 
involute, mostly less than 10 em. 
long; culms 20 to 40 cm. high.... 9, A. palmeri. 
Panicle branches more or less flexuous; 
blades elongated, flat below, in- 
volute at tip; culms often as 
much as | meter high........,. 10. A, longiramea. 
