200 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
2. Elyonurus tripsacoides Humb. & Bonpl.; Willd. Sp. Pl. 4: 941. 1806. 
Type locality, ‘‘Caracas,’’ Venezuela. 
RanGE: Southern United States to South America. 
HERBARIUM SPECIMENS FROM MEXICO: 
VERACRUZ: Jalapa, prairie, Hitchcock 6658; Smith 1623}. 
Curapas: Between San Ricardo and Ocozocuautla, Nelson 2990. 
2a. Elyonurus tripsacoides ciliaris (H. B. K.) Hack. in DC. Monogr. Phan. 6: 333. 
1889. 
Elyonurus ciliaris H. B. K. Nov. Gen. & Sp. 1: 133. 1816. 
Type locality, ‘‘in sylvis Orinocensibus prope Esmeraldam in radicibus nobilissimi 
montis Duide.’’ 
Rance: Mexico to Venezuela. 
HERBARIUM SPECIMENS FROM MEXICO: 
VERACRUZ: Orizaba, grassy hill, Hitchcock 6360; Bourgeau 2844; Botteri 163, 
669, 1264. 
13. ANDROPOGON L. Sp. Pl. 1045. 1753. 
KEY TO THE SPECIES. 
Spikes solitary at the ends of the stem or branches from bract- 
like sheaths (spikes sometimes solitary in A. furcatus of 
group 2). 
Plants annual. 
Outer glumes of sterile or pediceled spikelet enlarged, 
thin and bract-like, imbricated and partially 
hiding the spikelets. ............-...2.-...... 12. 
Outer glumes of sterile spikelets not enlarged. 
Culms weak and decumbent; blades oblong, 2 to 4 
cm. long; peduncles capillary, spreading... 1. 
Culms erect; blades linear, usually 8 to 20 cm. 
long; peduncles slender but not capillary, 
erect. 
Sessile spikelet scabrous, not pilose; rachilla 
joint with a few hairs at summit only.. 2. 
Sessile spikelet and rachilla joint pilose...... 3. 
Plants perennial (sometimes flowering the first year). 
Blades broad, short, firm, stiffly spreading, scattered 
along the wand-like culm; joints of rachis and 
sterile pedicels long-hairy. 
Axis of spike straight and stiff; spikes more loosely 
scattered along the culm.................. 11. 
Axis of spike slender and flexuous; spikes aggre- 
gated toward the summit, sometimes forming 
a flat-topped inflorescence. 
Plants without rootstocks; fertile lemma deeply 
2-cleft.... 2.22222... eee eee eee eee. 9. 
Plants with running rootstocks; fertile lemma 
entire or 2-toothed.................... 10. 
Blades long and narrow, lax and flexuous, the culms 
not wand-like. 
Spikes glabrous, awnless..............-.....---- 8. 
A. fastigiatus. 
A, brevifolius. 
A, gaumeri. 
A, malacostachyus. 
A. mexicanus. 
A. condensatus, 
A. muelleri. 
A. salemanni. 
