THE INDIAN SPECIES OF EKIOCAULON. 137 



The Arrangement of the Species. 



As far as the Indian species are concerned, if we except the local 

 floras founded on the F.B.I, there are, as stated ahove, only two 

 modern works giving descriptions, the F.B.I, and Euhland's mono- 

 graph of the whole family. Previous to this excellent descriptions 

 were given hy Steudel (Syn. PI. Cyperacearum 1858) and Koerniche 

 (Linnsea XXVII, 1854, pp. 577-692). 



The species are arranged in these two works on entirely different 

 plans. Hooker after separating the purely aquatic and submerged 

 forms, divided the remainder according to the external appearance of 

 the heads and the presence or absence of hairs on the receptacle. 

 Ruhland on the other hand arranged the species according to the num- 

 ber of parts in the flower, placing in his first section, which though 

 he does not so identify it I take to be Naysmithia Huds., those 

 with 2 parts to each whorl, in his second section those with 3 parts, 

 and in his third those with 3 parts in the staminal and carpellary 

 whorls but with fewer sepals or petals ; these sections being further 

 divided for convenience into the eastern or old-world species and the 

 western or new-world. He then took the nature of the stem whether 

 disciform or elongated, with such characters of the flower as white or 

 black anthers, crested or plain sepals, for the lesser divisions. The 

 difference in the two systems is very great. Two plants classed by 

 Hooker as dimerous and trimerous varieties of the same species, 

 E. sexangulare, appear in Euhlands monograph, as also in Steudel's 

 Syn. PI. Cyp., in different main divisions of the old world species, 

 and in the former s list as numbers 25 and 186 respectively. The 

 plant named by Trimen E. atratum Koerniche var. major was raised 

 by Hooker to the rank of a species, E. caulescens, and placed next to 

 E. robustum Steud. of the Nilgiris, from which it hardly differs except 

 in having a tall and branched stem ; whereas Ruhland separated the 

 two by no fewer than twelve Indian species, and placed E. robustum 

 next to E. quinqucangulare Linn., which in Hooker's arrangement is 

 separated from it by almost the whole of the Indian forms, one being 

 No. 4 and the other No. 35 out of 43. 



It would probably be correct to state that except in his main 

 divisions Ruhland in fact did not attempt to arrange the species in 

 phylogenetic groups, but only to provide a general clavis for aid in 

 their identification. Hooker made tentative groupings, but apart from 

 the separation of aquatic from terrestrial species made no definite 

 sections. 



Before attempting to classify the species of a genus it is clearly 

 necessary to determine what characters if any are liable to vary 

 with age or with the conditions of the environment, and further 



