CASUARINAS OR SHEOAKS. 35 
formed of a woody axis and hardened connate bracts and 
bracteoles, each pair of the latter enclosing a seedlike compressed 
fruitlet, which is elongated into a long membrane at the summit, 
the style forming a line through this membranous appendage. 
Seed solitary, compressed, surrounded by coiled or curled fibres 
or tubes (spiral vessels) between their outer adnate and their 
inner integument. Albumen none. Cotyledons oval, plan- 
convex, the short radicle lodged at their apex. The leaves of all 
Casuarinas are reduced to minute whorled teeth or bristles, 
arising from a cylindric joint. The transit of such diminutive or 
rudimentary leaves to those of more developed form can be traced 
in the somewhat allied order of Coniferee from Cypresses to 
Pines ; in reality the cylinders around the joints of the branchlets 
of Casuarinas must be regarded as formed by the concrescence of 
leaves, each teeth being merely the apex of a leaf. The wood 
shows the annual layers and the medullary rays very distinctly 
and contains also many spiral vessels. Many of the cells are 
filled with starch, as easily may be observed by treating the 
microscopic preparation with iodine. The order of Casuarinez 
belongs to that series of Dicotyledonez, called on account of the 
absence of a corolla or of petals Monochlamydee or Apetale, there 
being in such only one floral envelope. But Casuarine are by 
their floral organization widely removed from Conifers, and 
brought into closer affinity with Birches and Beeches, only the 
latter of which being represented in our colony and that by a 
solitary noble species, Fagus Cunninghami, our evergreen Beech, 
a native of some of the cooler forest-regions from Gippsland to 
Cape Otway, where it passes under the strangely inappropriate 
name Myrtle. 
Among the three tall-growing Casuarinas of our colony the 
one with erect dark-green foliage, the erect Casuarina (C. 
suberosa) is chosen for illustrative delineation (Figs. XIV. and 
XY.). Its whorls consist of 6 to 8 leaves ; the staminate spikes 
are slender; the stigmas are red; the lignescent bracteoles are in 
fruit protruding, only slightly acute and transversely thickened. 
This is a common species with us ; it extends to Tasmania, New 
South Wales and Queensland. 
C2 
