MR. O. BBNTHAM ON CYPEHA.CEJE. 365 



of Cypereae with Scirpese), and the larger genera themselves, are far 

 from being so strictly defined, and indeed, in several instances, do 

 not appear to be susceptible of accurate delineation. However 

 distinct such genera as Cyperus, Scirpus, ScJiosnus, Rhynchospora, 

 Hypoelytrum, &c. may be as to the great majority of species, 

 there will always be one, or some two or three, which might 

 almost equally well be placed in two or more of the genera. 

 Upon the whole, however, the following three tribes are tolerably 

 natural and, with few exceptions, well characterized : — 



1. Scirpese, with many-flowered spikelets and only 1 or rarely 

 2 empty glumes at the base ; the hypogynous setae or scales (more 

 properly the rudimentary perianth-segments) all setaceous or all 

 flat and regular. 



2. Hypolytreje, with the spikelets of Scirpeae,but within each 

 glume 2 complicate keeled scales, placed right and left, sometimes 

 more or less united, enclosing the stamens and pistil and in some 

 genera 2, 4, or more narrow flat scales, often twice as many as 

 stamens. This has induced some botanists to consider the flower 

 rather as a spikelet, with a single female naked flower surrounded 

 by 2 or more monandrous male flowers, each with one or two 

 glumes — a view, however, in which I feel unable to concur, as I 

 have already stated in my * Flora Australiensis.' 



3. Khxkchospoee^). — Spikelets with 1 or 2 (rarely 3 or 4) 

 perfect flowers, and often one or even more male flowers above 

 or below, and usually several empty glumes at the base. Hypo- 

 gynous seta? or scales present or absent, as in Scirpeae. 



There is but little to change as to the distribution of the genera 

 into these three tribes proposed by Kunth. Boeckeler was right 

 in transferring Remirea from the Scirpese to the Rhynchosporese; 

 and I think that Dichromena and Psilocarya, as Limited originally 

 to species with many-flowered spikelets, have the habit as well as 

 the characters of Scirpese ; whilst the Haloschceni, Kees, added by 

 Kunth to Dichromena as a section, and most of the South- 

 American species added by Nees to Psilocarya, are correctly 

 placed by Boeckeler in Rhynchospora itself. Among the other 

 genera of Rbynchosporese I have already, in the ' Flora Austra- 

 liensis,' proposed several alterations to Boeckeler's arrangement. 



The division of the strictly unisexual series of Cyperaceae into 

 two tribes (Sclerieae and Caricese), with or without an intermediate 

 one of Kobresieae or Elyneae, has not been so clearly marked out. 

 The utricle having been taken as the absolute character of Carex, 



