BOTANY OF TERRA AUSTRALIS.
natural orders, some of which are not included in Decandolle's list.
On such of these as either contribute largely to form the mass or the striking peculiarities of the Australian vegetation, I proceed to offer a few observations, chiefly on their geographical distribution, and more remarkable points of structure: taking them nearly in the same series in which they are given by Decandolle in the work already referred to.
MALVACEÆ. The Malvaceæ may be considered as a class including several orders, namely, Malvaceæ of Jussieu, Sterculiaceæ of Ventenat, Chlenaceæ of Du Petit Thouars, Tiliaceæ of Jussieu, and an order very nearly related to the last, and perhaps gradually passing into it, but which I shall in the mean time, distinguish under the name of Buttneriaceæ.
Of the Malvaceæ strictly so called, upwards of fifty species have been observed in Terra Australis, where the maximum of the order appears to be within the tropic. In the principal parallel Malvaceæ are more abundant at its eastern than its western extremity; and at the south end of Van Diemen's Island two species only have been observed. There is nothing very peculiar in the structure or appearance of the New Holland plants of this family; most of them belong to genera already established, and several of the species are common to other countries.
BUTTNERIACEÆ. The Australian portion of Buttneriaceæ consists of Abroma, Commersonia, Lasiopeta- [541 lum, and several unpublished genera, intermediate to the last two.
- Gen. pl. 271.
- Malmais. 91.
- Plant. des isles d' Afrique, 46.
- Gen. pl. 289.
- Buttneriaceæ. Calyx 1-ph. 5-fid. æqualis, marcescens, æstivatione valvata. Petala 5: vel basi saccata superne variè producta; vel minuta squamuliformia; quandoque nulla. Stamina hypogyna, definita: Filamenta antherifera cum laciniis calycis alternantia, simplicia, vel 2-3 connata; sterilibus quandoque alternantibus. Ovarium 3-5 loculare, loculis 2-polyspermis, ovulis erectis: Styli 3-5, sæpius connati: Stigmata simplicia. Capsula 3-5-loc. Semina: umbilico strophiolato. Embryo erectus, in axi albuminis carnosi cujus dimudio