TRISTEGINEJB. 



77 



many-flowered, yellowish, 15-30 cm. long, 3-5 cm. broad, rays 

 bearing spikelets along the upper half. Spikelets on pedicels 1-2 

 or more mm. long. First glume ovate-lanceolate, extending to the 

 top of tlio florets, 3-nerved, 3-3.5 mm. long including the stout 

 point, rachilla broad and carrying the second glume 0.3 mm. above 

 the first glume, second glume linear-lanceolate, 5-nerved, 4-5 mm. 

 long, including the stout point, third glume (floral glume of the 

 staminate floret) ovate-lanceolate, 2.5 mm. long, delicately 5-nerved, 

 lateral nerves near each other, its palea 2 mm. long, fourth glume 

 (floral glume of the upper floret) membranous, delicately 3-nerved, 

 1.7 mm. long, bearing a tuft of very short hairs at its base, and a 

 terminal awn 6-10 mm. long, the lower tliird of which is brown 

 and twisted. 



a A b 



Fig. 20. — Arundinella Palmeri. A, a, Beppeana; B, b, spikelets and florets 

 respectively. (Scribner.) 



Nearly allied to A. jjallida Nees, of which it is possibly only a 

 variety. Mexico, Palmer 12. 



2. A. pallida Nees, Agrost. Bras. 465 (1829). 



A rather smooth, stout, erect perennial. Culms hard, 180-200 

 cm. high. Ligule very short; blades smooth below, scabred or 

 pubescent above, 25-40 cm. long, 6-10 mm. wide. Panicle ovoid 

 or narrower, 30-40 cm. long, rays smooth in threes to fives, spar- 

 ingly branched. Spikelets on pedicels 1-2 mm. long, scattered the 



