In Casuarina, Juglans and the order Corylaceae, the pollen-tube does not enter by means of the micropyle, but passing down the ovary wall and through the placenta, enters at the chalazal end of the ovule.
In places the sands are fringed by long lines of Casuarina trees; in others, and more especially in the neighbourhood of some of the river mouths, there are deep banks of black mud covered with mangroves; in others the coast presents to the sea bold headlands, cliffs, mostly of a reddish hue, sparsely clad with greenery, or rolling hills covered by a growth of rank grass.
The finer branches are green, and bear a close resemblance to the stems of Equisetum and to the slender twigs of Casuarina; the surface of the long internodes is marked by fine longitudinal ribs, and at the nodes are borne pairs of inconspicuous scale-leaves.
On the east coast the force of the north-east monsoon, which beats upon the shores of the China Sea annually from November to February, has kept the land for the most part free from mangroves, and the sands, broken here and there by rocky headlands thickly wooded, and fringed by casuarina trees, stretch for miles without interruption.
The liquidambar and nutmeg may be noticed among the former; the first is one of the most conspicuous trees in Java, on the mountains of the eastern part of which the casuarina, one of the characteristic forms of Australia, is also abundant.
The Australian Eucalyptus and Casuarina in great variety, and many other imported trees, including syringas, wattles, acacias, willows, pines, cypress, cork and oak all thrive when properly planted and protected from grass fires.
Amongst the most remarkable galls recently discovered we may mention those found on Eucalyptus, Casuarina and other trees and plants in Australia.
In the natural order Rosaceae, the series Querciflorae, and the very anomalous genus Casuarina and others, instead of a single macrospore a more or less extensive sporogenous tissue is formed, but only one cell proceeds to the formation of a functional female cell.
Recent additions are the eucalyptus, casuarina, Pinus pinea and ailanthus.
This contains a large variety of hard-wooded and valuable timber trees, including species of Weinmannia (Lalona 1), Elaeocarpus (Voanana), Dalbergia (Vbambbana), Nuxia (Valanirana), Podocarpus, a pine, the sole species in the island (Hetatra),Tambourissa (Amhara), Neobaronia (Harah¢ra), Ocotea (Varongy) and probably ebony, Diospyros sp., &c. The following trees are characteristic of Madagascar vegetation, some of them being endemic, and others very prominent features in the landscape: the traveller's-tree (Urania speciosa), with its graceful crown of plantain-like leaves growing like an enormous fan at the top of a tall trunk, and affording a supply of pure cool water, every part of the tree being of some service in building; the Raphia (rofia) palm (Sagus ruffia); the tall fir-like Casuarina equisetifolia or beef wood tree, very prominent on the eastern coast, as well as several species of screw-pine (Pandanus); the Madagascar spice (Ravintsara madagascariensis), a large forest tree, with fragrant fruit, leaves and bark; a beautiful-leaved species of Calophyllum; and the Tangena (Tanghinia veneniflua), formerly employed as a poison ordeal.
The Mount Vernon beds, which occur about the middle of the series, have as yet yielded only a small number of species, though these include the most interesting early Angiosperms. Among them are recorded a Casuarina, a leaf of Sagittaria (which however, as observed by Zeiller, may belong to Smilax), two species of poplar-like leaves with remarkably cordate bases, Menispermites (possibly a water-lily) and Celastrophyllum (perhaps allied to Celastrus).
On the eastern side the plains and rocky ridges, where not artificially cleared, are occupied by shaggy and often sombre forests mainly composed of the following genera: Eucalyptus (gum tree), Casuarina, Bursaria, Acacia, Leptospermum, Drimys, Melaleuca, Dodonaea, Notolea, Exocarpus, Hakea, Epacris, Xanthorrhoea, Frenela.