Page:The Journal of Indian Botany.djvu/582

146 THE JOURNAL OF INDIAN BOTANY. Mountains from Mt. Aboo to Coorg, but do not go further north, east or south.

The group collinum-quinquangulare-trilobum-Dianae, has collec- tively the widest distribution, and shows very interesting develop- ments and cross-relationships. E. quinguangulare belongs to the plains of Ceylon, S. India and the Deccan, extending only rarely to the Western side in Canara. On the mountains to the south it is re- placed by E. collinum Hook. f. and to the north in Bengal by E. tri- lobum Ham,, both of which hardly differs from it except in the much darker head and better developed sepals, but are really quite easily distinguished. E. quinguangulare and E. trilobum have their counter- part on the wastern side in E. Dianae Sp. Nov. which in its widely differing varieties is similar to both, but differs in the reduction of one sepal to generally only a bristle and in the involucral bracts being usually longer. E. collinum has likewise in Ceylon one sepal smaller than the others, but the forms are not otherwise distinguishable. Both E. quinquangulare and E. Dianae show lengthening of the invo- ucral bracts, though the former only in Burma ; and E. xeranthemum with sometimes 3 female sepals sometimes 2, might be derived from either. It is in fact as if the two species E. quinquangulare and E. trilobum, and perhaps also E. collinum, were originally one, and developed from it as varieties and later on species, in — (l) the plains of S. India : and L. Bengal, (2) Upper Bengal, and (3) the mountains of S. India : and further as if these have independantly suffered a reduction in one sepal of the female flower ; the first two in travelling westwards across the Ghats to the sea, the third in crossing over to Ceylon. Another change was a lengthening of the involucral bracts, which seems to have proceeded independently in both E. quinquangulare and the derivative E. Dianae, as it has done also in other species.

The Mendelian would doubtless find in crossing a sufficient ex- planation of these double relationships, but it remains that the species as here defined occupy distinct areas and are found together if at all only on the borders of contiguous fields.

F.B.I.— Flora of British India, by J. D. Hooker. Volume ; VI, (1894)

pages quoted in Arabic numerals : a species number given

thus, No. 3. Ruhl, — Die Eriocaulaceae by W. Ruhland in Engler's Das Pflanzen-

reich (1903). The serial number of the species alone is

quoted.