HITCHCOCK AND CHASE GRASSES OF THE WEST INDIES. 271 



11. FESTUCEAE. 



Lemmas cleft at the summit into numerous awns ; panicle contracted, elongate. 



88. Pappophorum (p. 385). 

 Lemmas with a single awn or awnless. 



Spikelets (at least the pistillate) with copious long silky hairs on the 

 lemmas or the rachilla ; tall reeds with large plumy panicles. 

 Spikelets unisexual; pistillate spikelets hairy, the staminate glabrous; 



plants dioecious 90. Gynerium (p. 385). 



Spikelets perfect. 



Lemmas hairy ; rachilla glabrous 91. Arundo (p. 386). 



Lemmas glabrous; rachilla hairy 92. Phragmites (p. 386). 



Spikelets not long-hairy, the hairs if present much shorter than the lemma. 

 Glumes leaflike; spikelets concealed in the upper sheaths; plants 



dioecious 89. Monanthochloe (p. 385). 



Glumes not leaflike ; spikelets exposed. 



Stigmas elongate, wiry, coiled, tendril -like ; spikelets in a long 



1-sided raceme 98. Streptogyne (p. 393). 



Stigmas not elongate nor wiry. 

 Blades broad, ovate to elliptic, showing transverse veins between 

 the nerves. 

 Spikelets 3 to 5-flowered; glumes broad, truncate; panicles 



small 94. Senites (p. 392). 



Spikelets 1 or 2-flowered, the second floret commonly obsolete, 

 the elongate rachilla only present; glumes acuminate; 



panicles large, diffuse 95. Orthoclada (p. 393). 



Blades linear, no transverse veins showing. 



Spikelets in 1-sided dense clusters, these at the ends of the few 



stiff panicle branches 100. Dactylis (p. 394). 



Spikelets not in 1-sided clusters. 



Lemmas 3 nerved 93. Eragrostis (p. 387). 



Lemmas 5 or more nerved. 



Lowest 1 to 4 lemmas empty ; spikelets firm, strongly com- 

 pressed. 

 Plants hermaphrodite, usually more than 50 cm. tall. 



97. Uniola (p. 393). 

 Plants dioecious, usually less than 30 cm. tall. 



98. Distichlis (p. 394). 

 Lowest lemmas fertile. 



Florets horizontally spreading ; lemmas cordate at base. 



99. Briza (p. 394). 

 Florets ascending; lemmas not cordate. 

 Lemmas awnless ; spikelets small. 



Spikelets ovate or elliptic, few-flowered ; lemmas 



keeled 101. Poa (p. 395). 



Spikelets linear, many-flowered ; lemmas rounded on 



the back 103. Scleropoa (p. 396). 



Lemmas awned or mucronate (if aAvnless the spikelets 

 large). 



Awn from the tip 102. Festuca (p. 395). 



Awn from a bifid apex or wanting. 



104. Bromus (p. 396). 

 47877°— 17 2 



