Page:A Voyage to Terra Australis Volume 2.djvu/593

Natural Orders.] RESTIACEÆ. The principal character distinguishing this family from Junceæ and Cyperaceæ consists in its lenticular Embryo being placed at the extremity of the seed opposite to the umbilicus; from Junceæ it also differs in the order of suppression of its stamina, which when reduced to three are opposite to the inner laciniæ of the perianthium; and most of its genera are distinguishable from both these orders as well as from Commelineæ by their simple or unilocular antheræ.

With the exception of Eriocaulon, Tonina, and Xyris, the order appears to be confined to the Southern hemisphere. In Terra Australis its maximum is in the principal parallel, but it extends to the southern extremity of Van Diemen's Island, where it is even in considerable abundance, and exists, though much more sparingly within the tropic.

Restiaceæ are almost equally numerous at the Cape of Good Hope, as in the principal parallel of New Holland. One species only of the order has been observed in New Zealand, and hitherto none in South America.

CYPERACEÆ. In Terra Australis this is a very extensive order, consisting already of more than 200 species. It contains, however, fewer peculiarities in structure than several other orders that are much less numerous. Its maximum appears to be in the principal parallel; but the species observed solely within the tropic exceed one-third of the whole number. Cyperaceæ, in many respects, are nearly related to Restiaceæ, and when furnished with a true perianthium are distinguishable from the monospermous genera of that order, solely by the different position of the Embryo in the seed. But in the greater part of the order the Perianthium is either entirely wanting or merely setaceous. Fuirena, Lepidosperma and Orcobolus, all of them natives of New Holland, are almost the only genera in which it is found of nearly the usual appearance.

What I have formerly termed Perianthium in Carex, Diplacrum, and Schœnus nemorum, ought, perhaps, rather to be considered as internal lateral bracteæ, analogous to those of Lepyrodia, of Irideæ, and, perhaps, to the upper valve of the inner envelope of grasses.

I have formerly remarked that the Perianthium of Hypœlyptum