250 CASUARINACEiE. [Diclinous Exogens. 



Goeppert has examiiied the tunber anatomically, (Ann. Sc. N., 2 ser., 18. 1.) He 

 finds it to consist of woody bundles separated by medvdlary rays in the usual way, 

 and divided by interi'upted concentrical bands of cellular substance. There is no trace 

 of any tendency to form annual growth ; for the appearance of it, caused by the con- 

 centrical bands above meaitioned, is illusory. 



Brown, in the Appendix to Flinders's Voyage, has the following observations on the 

 structure of tliis remarkable genus : — " In the male flowers of aU the species of Casua- 

 rma, I find an envelope of fom- valves, as Labillardiere has akeady observed in one 

 species, which he has therefore named C. quadrivalvis. But as the two lateral valves 

 of this envelope cover the others in the unexpanded state, and appear to belong to a 

 distinct series, I am inclmed to consider them as bractese. On this supposition, which, 

 however, I do not advance with much confidence, the perianthum would consist merely 

 of the anterior and posterior valves ; and these, firmly cohering at their apices, are 

 earned up by the anthera, as soon as the filament begins to be produced, while the 

 lateral valves or bractese are persistent ; it follows from it, also, that there is no \isible 

 perianthum in the female flower ; and the remarkable economy of its lateral bractese 

 may, perhaps, be considered as not only aftording an additional ai'gument in support of 

 the view now taken of tlie nature of the parts, but also as in some degree agam 

 approximating Casuarma to Coniferee, with wliich it was formerly associated. The 

 outer coat of the seed or caryopsis of Casuarina consists of a very fine membrane, of 

 which the termuial wing is entirely composed ; between this membrane and the crusta- 

 ceous integument of the seed, there exists a stratum of spiral vessels, which Labil- 

 lardiere, not having distmctly seen, has described as an 'mtegumentum araclmoideum ;' 

 and within the crustaceous mtegument there is a thin proper membrane, closely applied 

 to the embryo, which the same author has entu'ely overlooked. The existence of 

 spiral vessels, particularly in such quantity, and, as far as can be detennined m the di'ied 

 specimens, unaccompanied by other vessels, is a structure at least very miusual in the 

 integuments of a seed or cai'yopsis, in which they are very seldom at all vdsible ; and 

 have never, I believe, been observed in such abundance as in this genus, in all whose 

 sjiecies they are equally obvious." 



These are for the most part Australasian trees or scnibby bushes, chiefly confined 

 to the more temperate latitudes of that vast island. One species only, C. equisetifoha, 

 is recorded as inliabiting the tropics of the Indian Archipelago ; and another, C.nodiflora, 

 is met with in New Caledonia. 



Not\\'ithstanding their want of leaves, these plants are remarkable for the excellence 

 of their timber, Avhich is hard, heavy, and resembling the colom' of raw beef, whence 

 their Colonial name. The heavy war clubs of the New Hollanders are said to have been 

 fashioned out of it. The baa'k of C. equisetifblia is shghtly astringent ; that of C. muri- 

 cata is said to be employed m India, in infusion, as a tonic. According to Backhouse, 

 ( Visit to Australia, App. xxx\di.), the yovmg branches and young cones of C. quadrival- 

 vis, or she-oak, when chewed, yield a pleasant acid, extremely useful to persons in want 

 of water. Cattle are also exceedingly fond of them. 



GENUS. 



Casuarina, L. 



Numbers. Gen. 1. Sp. 20. {Endl.) 



Gnetacece. 

 Position. — M^Tieacese. — Casuarinacejs. — Betulacese. 



