22 



Fig. 11. Trachypogou polymorphus montufari Hack.— a, A pair of spikelets: 

 b, dorsal view of the sessile spikelet; c, d, e, /, 1st, 2d, 3d, and 4th glumes. 



11. TBACHYPOGON Nees Agrost. Bras. 341. 1829. Spikelets as in Andropogon, 

 1-flowered, in pairs at the nodes of the imperfectly articulated rachis, one nearly 

 sessile, awnless, sterile, the other pedicellate, fertile, and long-awned. Glumes 

 usually 4, the outer one rigid, inclosing the others; 2d a little smaller and less 

 rigid than the 1st; the 3d and 4th hyaline; 4th glume of the pedicellate spike- 

 let very narrow at the base, and produced into a long twisted and geniculate 

 awn. Rather tall perennial grasses with narrow leaves and usually solitary, 

 long-exserted racemes. 



Species 1, presenting many varieties. Southern Africa and adjacent islands, 

 tropical and subtropical America, extending into Arizona. 



