Hortus Kewensis. Pistia is, I believe justly, placed here by Schreber and Willdenow.
5. Decandria. Geranium, properly so called, Engl. Bot. t. 404, 405, 272, &c., is the principal genus here. The late Professor Cavanilles, however, in his Dissertationes Botanicæ, referred to this Order a vast number of genera, never before suspected to belong to it, as Bannisteria, Malpighia, Turræa, Melia, &c., on account of some fancied union of their filaments, perhaps through the medium of a tubular nectary; which principle is absolutely inadmissible; for we might just as well refer to Monodelphia every plant whose filaments are connected by insertion into a tubular corolla. Some species of Oxalis, see p. 424, belong to this Order; as do several papilionaceous genera, of which we shall speak under the next Class.
6. Endecandria contains only the splendid South-American genus Brownea, the number of whose stamens is different in different species.
7. Dodecandria, Stamens mostly 15, is com-
