point of structure of its flower, and in most respects in that of its seed.
Oxalis, indeed, differs from Averrhoa in the texture of its fruits, in some respects in the structure of its seed; and very widely in habit, in the greater part of its species. The difference in habit, however, is not so great in some species of Oxalis; as for example, in those with pinnated and even ternate leaves from equinoctial America; and in that natural division of the genus including O. sensitiva, of which there are two species in the Congo herbarium. 433] This latter section of Oxalis[1] agrees also with Averrhoa Carambola[2] in the foliola, when irritated, being reflected or dependent, which is likewise their position in the state of collapsion or sleep, in all the species of both genera.
To the natural order formed by Oxalis and Averrhoa, the name of Oxalideæ may be given, in preference to that of Sensitivæ, under which, however, Batsch[3] was the first to propose the association of these two genera, and to point out their agreement in sensible qualities and irritability of leaves.
M. de Jussieu, in a memoir recently published,[4] has proposed to remove Oxalis from Geraniaceæ, to which he had formerly annexed it, and to unite it with Diosmeæ.
It appears to me to have a much nearer affinity to Zygophylleæ[5], though it is surely less intimately connected with that order than with Averrhoa.
I am aware that M. Correa de Serra, one of the most profound and philosophical botanists of the present age, has considered Averrhoa as nearly related to Rhamneæ[6] or rather to Celastrinæ; from which, however, it differs in the number and insertion of stamina and especially in the direction of the embryo, with respect to the pericarpium.
In all these characters Averrhoa agrees with Oxalis; its relation to which is further confirmed on considering the appendage of the seed or arillus, whose modifications in
