Obs. This genus forms a very unexpected addition to Annonaceæ, of which it will constitute a distinct section, remarkable in the manifestly perigynous insertion of its stamina and the cohesion of the tube of its calyx with the ovarium. It has therefore nearly the same relation to the other genera of the order that Nymphæa has to Hydropeltis: and the affinity in both cases is chiefly determined by the structure of the seed.
The operculum of Eupomatia, in which there is no mark of longitudinal division, may be considered as formed either of the calyx alone, or of the confluent calyx and corolla, as appears to be the case at least in several species of Eucalyptus.
A singular part of the structure of Eupomatia consists in its internal, barren, petal-like stamina, which, from their number and disposition, completely cut off all communication between the antheræ and stigmata. This communication appears to be restored by certain minute insects eating the petal-like filaments, while the antheriferous stamina, which are either expanded or reflected, and appear to be even slightly irritable, remain untouched. I have at least not unfrequently seen the barren stamina removed in this way, and, as all the stamina are firmly connected at the base and fall off together, it is difficult to conceive any other mode of exposing the stigmata to the influence of the antheræ.
599]EUDESMIA.
Ord. Nat. Myrtaceæ, inter Eucalyptum et Angophoram.
Syst. Linn. Polyadelphia Polyandria.
Char. Gen. Calyx superus, 4-dentatus. Petala arcte connata in Operculum 4-striatum deciduum. Stamina in phalanges quatuor polyandras, cum dentibus calycis alternantes, basi connata. Capsula 4-loc. polysperma, apice dehiscens.
