MANUAL OF THE GRASSES OF THE WEST INDIES 13 
Fertile spikelet without a callus, the rachis disarticulating immediately below 
the spikelet. 
Inflorescence a dense golden-brown silky panicle; spikelets awnless, the 
pedicellate one pistillate______________- 103. ErRtocurysis (p. 380). 
Inflorescence not a dense golden-brown silky panicle; pedicellate spikelet 
staminate or rudimentary. 
Pedicel of the sterile spikelet thickened, appressed to the thickened rachis 
joint or adnate to it; spikelets awnless, appressed to the joint. 
Rachis joint and pedicel adnate. Annuals. 
Perfect spikelet globose; sterile spikelet conspicuous. 
119. HacKELOCHLOA (p. 420). 
Perfect spikelet oblong; sterile spikelet minute. 
117. RorrTsoEr iia (p. 418). 
Rachis joint and pedicel distinct, the sessile spikelet appressed to them, 
its first glume lanceolate___________-_-- 118. Manisuris (p. 418). 
Pedicel of the sterile spikelet distinct, this and the rachis joint usually 
slender. 
Spikelets in reduced racemes of 1 to 5 (rarely 7) joints, these peduncled 
in open panicles; awns, if present, commonly deciduous. 
Pedicellate spikelets Staminaite sa4 | o-pesaes 111. SorcGuumM (p. 407). 
Pedicellate spikelets wanting, the pedicel only present. 
112. SorGHastrum (p. 409). 
Spikelets in evident racemes of several to many joints. 
Blades cordate, thin; pedicellate spikelets obsolete or present only in 
the lower part of the delicate subdigitate racemes. 
105. ARYHRAXON (p. 382). 
Blades linear, not cordate; pedicellate spikelets present, at least as 
rudiments. 
Inflorescence an elongate panicle of whorled long-peduncled slender 
glabrous racemes; spikelets muricate, awnless. 
110. VETIVERIA (p. 406). 
Inflorescence not a panicle of long-peduncled racemes; spikelets not 
muricate; racemes commonly conspicuously woolly. 
Margins of the first glume of the sterile spikelet involute, the 
sides rounded instead of sharply keeled. Racemes in pairs, 
reddish brown, 2 cm long, crowded in a large inflorescence. 
109. HyYPARRHENTA (p. 404). 
Margins of the first glume of the sessile spikelet inflexed, the 
glume sharply 2-keeled, the back flat or grooved between 
the keels. 
Pedicellate spikelets much larger than the sessile, almost con- 
cealing them, the first glume large and flat; racemes solitary 
oni the. branchess-c:i4 420) 4. 2 107. DiEctTomts (p. 402). 
Pedicellate spikelets sometimes as large as the sessile, usually 
smaller, the first glume not large and flat. 
Racemes single, in pairs, digitate, or numerous, sometimes 
supported by spathes; lowest pairs of spikelets like the 
upper, one fertile and sessile, the other pedicelJlate, stam- 
inate or reduced______--_- 106. ANDROPOGON (p. 385). 
Racemes in pairs subtended or enclosed by a broad spathe, 
aggregate in large compound panicles, the lowest pair of 
spikelets of one of the racemes alike, staminate or neuter. 
Aromatic grasses____.---- 108. CymMBoPocGon (p. 403). 
TRIBE 14. TRIPSACEAE 
Spikelets unisexual, the staminate in pairs, or sometimes in threes, 
2-flowered, the pistillate usually single, 2-flowered, the lower floret 
sterile, embedded in hollows of the thickened articulate axis and fall- 
ing attached to the joints, or enclosed in a thickened involucre or 
sheath; glumes membranaceous or thick and rigid, awnless; lemmas 
and palea hyaline, awnless. Plants monoecious. : 
Pistillate spikelets sunken in recesses in the thickened joints of the rachis; inflor- 
escence of solitary or digitate racemes_________- 121. Tripsacum (p. 423). 
Pistillate spikelets enclosed in a bony beadlike involucre__.122. Corx (p. 423). 
