NATURAL ORDERS. 145 



Richard's HypEelytruiu being lateral, or right and left 

 with respect to the axis of the spikelet,^ were compared to 

 those of the female flowers of Biplacrum, to the utriculus 

 or nectarium of Careas, and to the lateral bracteee of Lepy- 

 rodia, a genus belonghig to the nearly related order Res- 

 tiacese.' But as in HypcBlytrum, according to M. Richard's 

 description, and I believe also in his Diplasia^ there are 

 sometimes more than two inner squamae, which are then 

 imbricate, they may in both these genera be considered as 

 a spikelet reduced to a single flower, as in several other 

 genera of Cyperacese, and in Lipocarpha itself, from which, im 

 however, they are still sufficiently different in their relation 

 to the including squamse and to the axis of the spike. 



This view of the structure of Hypselytrum, of which 

 there is one species in the Congo herbarium, appears to 

 me in some degree confirmed by a comparison with that of 

 CJiondrachne and Chorizandra ;* for in both of these genera 

 the lower squamse of the ultimate spikelet are not barren, 

 but monandrous, the central or terminating flower only 

 being hermaphrodite. 



GRAMINE^. Of this extensive family there are forty- 

 five species from the Congo, or one twelfth of the Phseno- 

 gamous plants of the collection. This is very nearly the 

 equinoctial proportion of the order as given by Baron Hum- 

 boldt, namely, one to fifteen, with which that of India 

 seems to agree. On the north coast of New Holland, the 

 proportion is still greater than that of Congo. 



The two principal tribes which form the far greater part 

 of Graminese, namely, Poacece and Paniceae have, as I have 

 formerly stated,^ very different relations to climate, the 

 maximum both in the absolute and relative number of 

 species of Paniceae being evidently within the tropics, that 

 of Poacese beyond them. 



I have hitherto found this superiority of Panicese to 

 PoaceEe, at or near the level of the sea within the tropics, 



' Prodr. Flor. Nov. Boll. 1, f. 219. ^ Minders' s Voy. 2, p. 579. {Ante, p. 53.) 

 3 Persoon Syn. PI. 1, p. 70. ■" Prodr. Flor. Nov. Holl. 1, p. 220. 



» Prodr. Flor. Nov. Holl. ], p. 1G9. Obs. IT. Flinders's Toy. 2, p. 58d. 

 {Ante, p. 58.) 



