II. On the Genus Crescentia.

T H E genus Cmsceiztia was considercd by DeCandolle" to belong to a group of plants (the Crescentiea) forming a second tribe of the Biglzoniacecz.This he again divided into two subtribes, Tcinuecieci?and Cresceiztiecq-the former being distinguished by its siliquzform fruit with two or more cells, and opposite leaves, the latter by a unilocular fruit and alternate leaves.This arrangement was founded upon niuch misconception, as it will be presently shown that scarcely any of the genera coniprised in these groups bear any relation to Crescentict.Dr. Seemann, in 1852 f-, gave a new outline of the entire group, and a somewhat different arrangement of DeCandolle's genera.He there adopted Gardner's view-of niaking them a distinct natural order, the Crescelztiacea, and raised the subtribes of DeCandolle t o the rank of tribes, the Funaeciea being distinguished by having a regular, persistent, 5-fid clayx, and the Crescentiea by having an irregular, spathaceous or 2-partite, deciduous calyx.I n the Linnean Transactions, xxiii.p. 3, he gave a more extended diagnosis of the order within the boundaries he ascribed to it, comprising in his tribe Tunueciea the genera Coleu, Phyllartlaron, and Tccnueciacm (including in the latter the Schlegelia of Niquel), and placing in the Crescelztiea the genera Purnzentiem, Crescentia, and Kigeliu, giving at the same time the character not only of each genus, but of each species.I n 1861 $, I published some " Observations on the Bignoniaceze," in which I pointed out the normal structure of the ovary, fruit, and seed of the various groups of the family ; and (in p. 255) I commented on the CrescenLiea especially, and on its several genera, showing from my own investigations, and from the recorded observations of others, that a11 the genera of the Tunaeciea and nearly all those of the Crescmfiea should be exelrtded from the true Cresce&ie@, on account of their 2-locular ovary.In the Annals ' of the same year (vol.viii.p. 113), I gave a detailed account of the structure of the flower, fruit, and seed of Tanaecium, showing it t o be a true genus of the Bignoniece, closely allied to Adenocalynana, and that the Tulzaeciwn pumsiticum, Sw., and T. lilucinzcna, Seem., belong to the #chlegelicc of Miquel, a genus certainly distinct from Tanuecium on account of its seeds enveloped in pulp, and which, from its apparently 2-locular fruit, with seeds fixed upon the middle of the dissepiment, seems to belong to the same group that includes Platycurpwm, Hemriquexicc, Oxycladus, and Montteu.I showed also that all the genera of the Bigno&@ and Cutalpea have a 2-celled ovary and fruit, with the exception of Jacurunda, Calampelis, and Eccremocarpiis, which I proposed to unite into a distinct * Prodromus, ix.240.