30 MB. C. B. CLABKE ON INDIAN SPECIES OF CYPEBTJS. 



This structure of nut is very common in Isolepis, unknown in 

 Cyperus. 



These differences in the nut invariably accompany the differ- 

 ence in the arrangement of the glumes (biseriate or §) ; so that 

 thereby Isolepis Micheliana and Cyperus pygmceus are completely 

 carried apart to their several genera. 



These differences are supported by a number of trivial cha- 

 racters. In Cyperus pygmceus the glumes are ovate-lanceolate or 

 oblong-lanceolate, the filaments ligulate, the anthers somewhat 

 large linear-oblong, the style-branches longer than the nut, the 

 style itself nearly free from papillae, never 3-fid with me. In 

 Isolepis Micheliana the glumes are often somewhat widened at 

 the shoulder, oblong (subobovate) lanceolate ; the filaments 

 slender, the anthers small oblong, the style-branches shorter than 

 the nut, the style itself papillose, usually 2-tid, occasionally 

 3-fid. 



In plants that fruit superabundantly as these, a large number 

 of the nuts are never perfected. In Cyperus pygmceus a quantity 

 of pale-coloured nuts occur which will be found to contain do 

 perfected seed. These are often not only pale, but marcescent, 

 with very hyaline outermost cells ; and they must not be mis- 

 taken for the ripe seeds of the Isolepis. 



Parag. 3. On Cyperus alopecuroides and C. dives. 



Cyperus alopecuroides, Eottb., is a large species with very many 

 spikelets spicate in a large umbel, with a 2-fid style, nut com- 

 pressed contrary to the rhachilla, and is arranged in Sect. Jun- 

 cellus by Kunth, &c. 



C. dives, Delile, is very similar to it in size, bracts, and inflo- 

 rescence ; but has a 3-fid style and strongly trigonous nut. It 

 has been placed next C. exaltatus, Retz., and should be considered, 

 I think, a form only of that species. 



Boeckeler, in « Linnaea,' xxxvi. p. 322, unites C. alopecuroides, 

 Eottb., and C. dives. Benth. et Hook. f. Gen. PL iii. p. 1004, 

 say :— 



"C. alopecuroides, Rottb. (C. dives, Delile, PI. Eg. t. 4), habitu 

 C. (Papyro) exaltato, Retz., accedit, sed nux omnino Juncelli, 

 variat tamen stylo 2-fido v. praesertim in speciminibus Africanis 

 3-fido." 



In C. alopecuroides, Rottb., the style is always 2-fid, the nut 

 always compressed, and moreover the rhachilla (fig. 12) is very 



