HITCHCOCK—-MEXICAN GRASSES. 331 
Lemma awned. 
Rudimentary floret inconspicuous, narrow, not broadened 
at apex. 
Blades elongated, acuminate; spikes numerous, 10 to 
15 cm. long, scattered toward the summit of the 
culm; plant bearing cleistogamous underground 
spikelets........------ eee ee ee eeeeeceeeeeeees 10. C. clandestina. 
Blades mostly less than 10 cm. long; spikes several, 
more or less approximate, mostly not over 5 cm. 
long; no underground spikelets. 
Awn of lemma about 3 mm. long; rudiment about 
half as long as lemma......-----..----++-- 9. C. tenuispica. 
Awn of lemma 8 to 10 mm. long; rudiment very 
narrow, 0.5 mm. long, inclosed by the in- 
rolled lemma. .........-----------eeeeee- 8. C. radiata. 
Rudimentary floret evident, truncate, broadened at sum- 
mit. 
Awn shorter than the lemma; rudiment triangular- 
truncate. 
Lemma long-pilose on the keel and marginal nerves 
except at the base. .......-..+----------- 4. C. ciliata. 
Lemma slightly ciliate, but not pilose; rudiment 
hood-shaped...........--------+-ee++eee+- 3. C. cucullata. 
Awn more than twice as long as the lemma. 
Rudiment triangular-truncate, 2-awned.......---- 5. C. paraguayensis. 
Rudiment cuneate, twice as long as broad, 1- 
awned. 
Lemma conspicuously pilose on the margin 
above, the hairs 2mm. long.....------ 6. C. elegans. 
Lemma short-ciliate on the margins above, the 
hairs less than 1 mm. long...........-. 7. C. virgata. 
1. Chloris petraea Swartz, Prodr. Veg. Ind. Occ. 25. 1788. 
Type locality, ‘“‘Jamaica.”’ 
RANGE: Southern United States and West Indies to Costa Rica. 
HERBARIUM SPECIMENS FROM MEXICO: 
Tamauttpas: La Barra, Palmer 285 in 1910. Tampico, among brush in low land, 
Mitcheock 5798. 
2. Chloris submutica H. B. K. Nov. Gen. & Sp. 1: 167. pl. 50. 1816. 
Type locality, ‘‘in temperatis convallis Mexicanae propter littora Tezcucensis” 
[Lake Texcoco]. 
RanGE: Highlands of Mexico. 
HERBARIUM SPECIMENS: 
Curmvanva: Valley near Chihuahua, Pringle 424. Mifiaca, along railway, Hitch- 
cock 7731. 
Duranco: Durango, in stiff, black, waxy loam, Palmer 181 in 1896; dry ground, 
Hitchcock 7594. Otinapa, Palmer 341in 1906. Tepehuanes, Palmer 362 in 1906. 
CoaHuILA: Saltillo, near ditches in cornfields, Palmer 390 in 1898; Hitchcock 5588. 
Trric: Sierra Madre near Santa Teresa, Rose 2143. 
Zacatecas: Zacatecas, gulch in dry sterile hills, Hitchcock 7502. 
AGUASCALIENTES: Aguascalientes, edge of field, Hitchcock 7453. 
San Luis Porost: San Luis Potosf, edge of field, Hitchcock 5686; Schaffner 130. 
Jauisco: Guadalajara, Palmer 242 in 1886; open mesa, road to Barranca de Oblatos, 
Hitchcock 7313; fields, Pringle 11221. Zapotlan, railway right of way, Hitch- 
cock 7129. Orozco, alkaline soil, near large pond, Hitchcock 7380, 
