UR. &. tENTnAM ON GEAMINB^. 43 



The genus DimorphostaoJiys of Pournier is founded upon the 

 above P. monostachyum and some other American species, which we 

 should refer to the sections Digitaria or Srachiaria, but which 

 he connects generically by the small lowest glume being more 

 developed or differently shaped in one spikelet of each pair than 

 in the others ; but the difference is often exceedingly slight, 

 and the character so little connected with any other or with 

 habit, that it seems difficult to attach any more than specific 

 importance to it. 



(6) Bracliiaria. This section, sometimes referred to as Paspaloid 

 Panica, comprises a large number of species both from the New 

 and the Old World, in which the inflorescence is that which is 

 regarded as specially characteristic of Paspalum : the panicle con- 

 sists of a number of spike-like simple branches, distributed along 

 a simple common peduncle ; but the small lowest glume of Pani- 

 cum is always present. If we regard only such typical species as 

 P. flavidum or P. fiuiians of Eetz, or P. paspaloides of Persoon, 

 the section appears a most distinct one ; but, on the other hand, 

 several such species as P. adspersum, Trin., P. argenteum, Br., 

 P. Petiveri, Trin., P. poh/phyllum, Br., &c. so closely connect it 

 with some of the sparingly-flowered species of JEwpanicum, as to 

 make it impossible to draw a precise line of demarcation between 

 the two. Amongst these intermediate forms, Paracteenmn, pro- 

 posed as a genus by Beauvois, appears to be only a starved state 

 of P. gracile, Br. 



P. helopus, Trin., bears on the obtuse apex of the flowering 

 glume a short point, like that of most species of Eriochloa, and 

 was therefore joined by Beauvois to the P. {Trichachne) semi- 

 alatum, Br., to form his genus Urochloa ; but the two are in other 

 respects too dissimilar to be united in one section, and P. helopus 

 appears to be altogether a true Bracliiaria. 



(7) PicMiiooMoa, was regarded by Beauvois as a distinct genus, 

 founded chiefly on two very widely-spread and most variable 

 species, P. colonum, Linn., and P. crus-gaUi, Linn., the former 

 often cultivated, the latter a most abundant tropical and sub- 

 tropical weed. Both have nearly the inflorescence of the section 

 PracMaria but they are coarser plants, with the spikelets densely 

 crowded on the partial spikes or branches of the panicle, and the 

 second and third empty glumes, in the one rarely, in the other 

 very generally, terminating in long awns. It was probably on 

 this account that Kunth united Beauvois's JCcJiinochloa with his 



