GRIFFITHS — THE GEAMA GRASSES. 



403 



a ring of numerous long, white hairs; spikelets about 5 to 10, not pectinate, consisting 

 of 1 floret and a rudiment; glumes hispid and hairy-tufted at base, awned, the 

 first 6 mm., the second 10 mm. long, the latter having an abrupt constriction above, 

 the apex continued into two acuminate, awn-like teeth, 0.5 to 1 mm. long, on each side 

 of the central awn; lemma 11 to 12 mm. long including awns, smooth, shining, and 

 bone-like on the back, with 3 hispid, spreading awns about 5 mm. long, the lateral 

 awns nearly equal to the central; palet deeply sulcate on the back and involute on the 



Fig. 52. — Bouteloua megapotamica. a, Spikelet; b, c, lemma and palet of first floret; d-g, rudimentary sec- 

 ond, third, fourth, and fifth florets; h, two views and cross section of caryopsis. a, Scale 2.5; b-h, scale 

 5. From Arechavaleta, Montevideo. 



edges, 2-awned, 8 to 9 mm. long; rudiment consisting of 2 or 3 aborted florets appearing 

 like a cluster of 9 to 12 hispid awns of various degrees of rigidity, interspersed with 

 delicate narrow scales a fourth as long or less; caryopsis cylindrical-obovate, 2 to 2.5 

 mm. long, the scutellum covering about two-thirds of the ventral surface. (Figure 

 52.) 



Stuckert's no. 27, Kneucker's Gram. Exs. 376, and Arechavaleta from Montevideo, 

 are typical. The latter shows the stoloniferous character beautifully. 



