Eudesmia tetragona. Tab. 3.
In exposed barren places near the shores, in the neighbourhood of Lucky Bay, on the south coast of New Holland in 34° S. lat. and 123° E. lon.; gathered both in flower and fruit in January, 1802.
DESC. Frutex 3-5 pedes altus, ramis patentibus, ramulis 4-gonis angulis marginatis. Folia opposita quandoque subopposita, petiolata, sæpius aversa, lanceolata vel oblonga, coriacea compacta, integerrima marginata glauca resinoso-punctata, venis vix emersis anastoniozantibus, 3-4 uncias longa, 14-16 lineas lata. Umbellæ laterales paucifloræ pedunculo pedicellisque ancipitibus. Calyx turbinatus obtuse 4-gonus cum ovario cohærens, angulis apice productis in dentes breves subinæquales, duobus oppositis paulo majoribus. Operculum depresso-hemisphæricum muticum glandulosum albicans, striis quatuor cruciatis parum depressis dentibus calycis oppositis notatum, quasi e petalis quatuor conflatum, caducum. Stamina plurima; Filamenta in phalanges quatuor petalis oppositas approximata, capillaria glabra alba, interiora sensim breviora; Antheræ ovato-subrotundæ incumbentes ochroleucæ, loculis longitudinaliter dehiscentibus. Ovarium inclusum tubo adherenti calycis, 4-loculare: Stylus 1, cylindraceus; Stigma obtusum. Capsula inclusa et connata tubo aucto turbinato oblongo ligneo calycis, apice 4-fariam dehiscens.
Obs. There can be no doubt respecting the affinity of this genus, which belongs to Myrtaceæ and differs from Eucalyptus solely in having a striated operculum placed within a distinctly toothed calyx, and in its filaments being collected into bundles. The operculum in Eudesmia, from the nature of its striæ and their relation to the teeth of the calyx, appears to be formed of the confluent petals only; whereas, that of Eucalyptus, which is neither striated nor placed within a distinct calyx, is more probably composed, in several cases at least, of both floral envelopes united. But in many species of Eucalyptus a double operculum has been observed; in these the outer operculum, which generally separates at a much earlier stage, may, perhaps, be considered as formed of the calyx, and [600 the inner consequently of corolla alone, as in Eudesmia: this view of the structure appears at least very probable in contemplating Eucalyptus globulus, in which the cicatrix caused by the separation of the outer operculum is particularly obvious, and in which also the inner operculum is of an evidently different form.
Jussieu, in some observations which he has lately made on this subject, (in Annales du mus. 19. p. 432,) seems inclined to consider the operculum of Eucalyptus as
