ME. C. B. CLAEKE ON INDIAN SPECIES OF CTPEET7S. 29 



genera, undoubtedly distinct ; though from the synonymy quoted 

 it appears that they had been confounded, by reason of superficial 

 resemblances. 



Boeckeler, in ' Linnsea,' xxxv. p. 493,(c/! Boeck. in 'Flora,' 1871, 

 p. 158), unites the two under one species, Cyperus pygmceus ; 

 he esteems Isolepis Micheliana a form merely " squamis trifariam 

 imbricatis." The number of stamens which he gives for C. pyg- 

 mcBus and I. Micheliana is a character of no value; the number of 

 stamens in fairly developed C. pygmceus is two ; but the number 

 is not constant in one spikelet of either species. The glumes of 

 I. Micheliana are, however, not trifarious, but on the regular § 

 arrangement. 



Benth. et Hook. f. Gen. PI. iii. p. 1044, follow Boeckeler. 



I have no doubt that the two plants are amply distinct, and 

 that Kunth's view is correct. 



If we examine a good series of the Cyperus with ripe nuts, we shall 

 find that though superficially the glumes appear somewhat irre- 

 gularly placed on the rhachilla, that is not really so. The irregu- 

 larity disappears under the microscope. The spikelets are densely 

 crowded, hence curved aud sometimes twisted as in many other 

 species of Cyperus ; but if we examine the upper two-third part 

 of a ripe spikelet, the glumes are accurately biseriate, and the 

 rhachilla "alternatim excavata" as in other typical Cyperi. 



In I. Micheliana, on the other hand, the glumes of the upper 

 two-third part of a spikelet with ripe nuts are seen to be on the 

 § arrangement with lozenge-shaped scars after they have fallen 

 from the rhachilla. The distinction is so marked that I imagine 

 confusion to have arisen only from examining herbarium spe- 

 cimens of immature heads with a lens. Such specimens with 

 unripe nuts are difficult to separate, even by dissection, because 

 the best characters in support of the foregoing (to separate the 

 two plants) depend on the nut. 



The nut of C. pygrnceus (fig. 10) is, when fully developed, 

 chestnut-coloured, the outer cells are the quadrate cells common 

 in Cyperus ; the outermost layer is hyaline punctate, but not very 

 thick or lax ; so that when the nut is viewed under the micro- 

 scope it has no hyaline margin all round it. 



The nut of Isolepis Micheliana (fig. 11) is yellow, or a very pale 

 yellow-brown ; the two outer layers of cells are hyaline, inflated, 

 lax; so that when the nut is viewed under the microscope it 

 appears surrounded on all sides by a broad hyaline margin. 



