[ 267 ] XIII. Review of the Order of Hydropliylleae. Bi/ George Bentham, Esq., F.L.S. Read June 17th, 1834. On the occasion of publishing some new ornamental species of Nemophila and Phacelia, received by the Horticultural Society from Mr. Douglas, the collector whom they had sent out to the North-west Coast of America, I have been led to examine the whole of the species of the small tribe to which they belong, contained in my own and the Horticultural Society's herbaria. The result having induced me to entertain some doubts as to the importance of some of the characters upon which the generic distinctions have been esta-blished, I have committed my observations to paper, together with a short review of the whole of the species of which the order is now composed, in the hope that they might not prove unacceptable to the Linnean Society. This group of plants was first indicated as a natural order by Mr. Brown in his Prodromus Florce Novce Hollandlce, where, with his usual acumen and conciseness, he observes (p. 492.), " Distincti (a Borragineis) ordinis initia con-stituunt genera capsularia Hydrophyllum, Phacelia, et ElUsia, ob albumen copiosum cartilagineum, et folia composita vel alte lobata." To this group Mr. Brown afterwards gave the name of Hydrophyllece, and added the Nemo-phila of Barton (Bot. Mag. 50. t. 2373.), and a new genus under the name of Eutoca (App. to Franklin's Voyage). These five genera, together with one I now propose to name Emmenanthe, contain the whole of the thirty-two species now known ; or if it should appear, upon further observation, that Nemophila should be considered as a section of ElUsia, and Eutoca be joined to Phacelia, the whole tribe would be reduced to four natural and well-defined genera. All these plants agree in those essential characters which, as stated by Mr. Brown, separate them from their nearest allies, the Borraginece, that is to say, in their capsular fruit and copious albumen ; and the structure of the VOL. XVII. 2 N
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