4 MS. C. B. CLARKE ON INDIAN SPECIES OP OYPERUS. 



has subsequently made the new species C. microcarpus, Boeck. 

 C.flavidus, I believe, never exists more than six months; it is 

 one of the universal annuals in late dibbled rice, the culms are 

 often clustered with tangled fibrous roots, and appear sometimes 

 to grow together (fig. 25); but I have never seen any thing like 

 a rhizome in this species. 



But though there are these (and other) difficulties in employ- 

 ing the general characters of the rhizome for the discrimination 

 of species, the particular characters of the rhizome are in many 

 species exceedingly constant for that species, and in some cases 

 afford the best specific character we have. 



In C. rotundus, Linn. (fig. 16), the culm arises from a nodule of 

 the rhizome, the remainder of the rhizome being slender wiry ; 

 the nodule is formed by a number of shortened joints of the 

 rhizome, secreting much starch, whence the strain on the plant 

 caused by fruiting is met. 



In C. longus (fig. 14) the rhizome is nearly uniformly thick ; 

 there are uo very prominent nodules whence the culms spring, 

 nor any very slender wiry portions between. I confidently refer 

 Aitchison's n. 684 (marked by Boeckeler C. longus) to 0. rotundus. 

 A species much confounded with the preceding is G. escu- 

 lentus, Linn. (fig. 15) ; the stolons are very slender, herbaceous, 

 not wiry. In this species (and in many others, as C. procerus) 

 they appear to burst from the base of a floweriug culm; 

 whereas in G. longus, C. Haspan, &c. the rhizome creeps and the 

 flowering culms spring from a subterminal bud on it. But both 

 these modes of growth may be seen in the same plant of G. arti- 

 culatus, G. scariosus (fig. 22), and others. C. esculentus and 

 many other species produce tubers on the rhizomes. 



Another plant much confounded with G. rotundus is C. jemi- 

 nicus (fig. 17, 18), which is very easily separable by the rhizome, 

 the base of each culm being enclosed in black horny prominent 

 lanceolate cuspidate scales. Fig. 18 shows one culm in flower, 

 the next not started from the circle of black scales ; while fig. 17 

 shows the same with the black scales rubbed off from the base 

 of the culm, a common state in herbaria, as the scales are ulti- 

 mately caducous ; and if a herbarium specimen shows no young 

 circle of black scales, it is usually marked 0. rotundus. G. usi- 

 tatus, Burchell, is very near 0. jeminicus ; but in it the rhizome 

 is wiry elongate, so that the thickened " bulb " is usually 1-4 

 eentim. distant from the base of the flowering culm. 



