No. 33. 

 CHLORIS VERTICILLATA Nuttall. 



Plant annual. 



Culms single or few in a tuft, 10 to 16 inches high, branching at the base, the 

 branches commonly sterile, spreading below. 



Leaves sometimes obtuse, but usually acuminate, at the apex; sheath provided 

 at the throat, especially near the margin within, with a few long slender hairs. 



Inflorescence short-pedunculate or sometimes sheathed below. Spikes 8 to 14, 

 4 to 6 inches long, often naked at the base, clustered at the apex of the stem and 

 at that point hairy, or a few verticillate branches in 1 or 2 series on a prolon- 

 gation of the axis. Spikelets arranged in 2 rows on one side of the slender, sca- 

 brous rachis, at intervals in each row of about 2 to 2| lines. 



Spikelet about 1| lines long, cuneate-obovate, compressed. 



Glumes 4; first and second with 1 scabrous nerve, first as long as the spike- 

 let, lanceolate, aristate-acute; second with a longer point, exceeding the spikelet; 

 third (flowering) glume 3-nerved, bearing a slender scabrous awn (4 to 5 lines long) 

 below the apex, broadly oblong, bluntly acute at each end, short-pilose on the mid- 

 rib and intramarginal nerves, elsewhere glabrous; fourth (sterile) glume broadly 

 obovate, nearly truncate, 3-nerved, glabrous, with an awn 3 to 4 lines long; small 

 fifth glume, similar in form to fourth, usually present. 



Flower sometimes single, hermaphrodite. Palet narrowly oblong, 2-nerved, 

 nerves ciliate and margins innexed. Staines 3; anthers minute. Stigmas cylin- 

 drical. Flower often present in the axil of the fourth glume, sometimes her- 

 maphrodite, sometimes reduced to an empty palet. 



Grain not seen. 



Plate XXXIII; a, spikelet opened to show the parts, the rachis broken. The 

 figure represents an unexpanded panicle; when expanded, the branches are spread 

 at right angles with the axis. 



