250 CASUARINACEiE. [Diclinous Exogens. 



Goeppert has examined the timber anatomically, (Ann. Sc. N., 2 sec, 18. 1.) He 

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

 and divided by interrupted 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 mentioned, is illusory. 



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

 structure of this remarkable genus : — " In the male flowers of all the species of Casua- 

 rina, I find an envelope of four valves, as Labillardiere has already observed in one 

 species, which he has therefore named G. 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 inclined to consider them as bractete. 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 

 carried 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 visible 

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

 may, perhaps, be considered as not only affording an additional argument in support of 

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

 approximating Casuarina to Coniferse, with which it was formerly associated. . The 

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

 which the terminal 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 distinctly seen, has described as an ' integumentum arachnoideum ;' 

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

 to the embryo, which the same author has entirely overlooked. The existence of 

 spiral vessels, particularly in such quantity, and, as far as can be determined in the dried 

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

 integuments of a seed or caryopsis, in which they are very seldom at all visible ; and 

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

 species they are equally obvious." 



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

 to the more temperate latitudes of that vast island. One species omy, C. equisetifolia, 

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

 is met with in New Caledonia. 



Notwithstanding their want of leaves, these plants are remarkable for the excellence 

 of then' timber, which is hard, heavy, and resembling the colour 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 bark of C. equisetifolia is slightly astringent ; that of C. niuri- 

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

 ( Visit to Australia, App. xxxvii.), the young 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. (L'ndl.) 



Gnetacece. 

 Position. — Myricacene. — Casuarinack* — Betulacese. 



Seethe Revisio cri/ica Casaarinarum, Amst. 1S48, 4to, by Miquel, who enumerates 

 32 supposed species. 



