184 Chase — Notes on Genera of Pankeae. I. 



nearer relatives left in the genus Paspalum. The foregoing does 

 not mean that the fruit is held to be the only generic character 

 but merely that it is a strong one which has not received the 

 attention it deserves; while it is held that any generic character 

 must be constant in a species and assemble species having other 

 affinities. Such a character is the reversed position of the 

 spikelets in Axonopus Beauv. (Anastrophm Schlecht.). The 

 fruits alone would not separate this genus from Paspalum, but 

 not one of the many specimens of the several species examined 

 shows a spikelet placed otherwise than with the back of the fruit 

 turned from the rachis. 



These studies are based on the material in the National Herba- 

 rium where all the genera of this tribe are represented, most of 

 them by a large series of specimens. The figures* and descrip- 

 tions are drawn from mature or nearly mature fruits; since the 

 spikelets fall at maturity it is difficult to rind perfectly ripe fruit 

 in herbarium specimens. 



The present paper is confined to that group of Paniceae in which 

 the fruits are cartilaginous-indurated (not rigid) papillose, and 

 usually dark colored; lemmas and paleas alike in texture, the 

 lemmas with more or less prominent, white, hyaline margins not 

 in rolled. 



Key. 



Lemma boat-shaped, margin narrow Anthaenantia 



Lemma convex only. 

 Palea not inclosed above, lemma byaline at tlie summit. Lrpiocorypliium 

 Palea inclosed, lemma with broad hyaline margin nearly 

 to the base. 

 Fruit lanceolate-acuminate, second glume and sterile 

 lemma clothed with long hairs exceeding the 



spikelet, grain unequally biconvex Valota 



Fruit elliptic ; second glume and sterile lemma clothed 

 with short hairs or nearly glabrous, grain plano- 

 convex in section. 

 Spikelets disposed in 1-sided racemes which are 



digitate or racemose Syntherisma 



Spikelets in panicles divergent at maturity . . . . Leptoloma 



Gknus ANTHAENANTIA Beauv. 1812. Agros. 48. t. 10. f. 7. 



Axis paniculatus: Panicula subsimplex. — Glumse subaequales, concave, 

 herbaceae. — Fi.osc. infer, neut. : Paleee membranaceae, oppositse, I'aleis 

 * The figures are all magnified «Q diameters. 



/ 



