206 



DOMESTIC BOTANY. 



to the genus Casuarina, chiefly natives of Australia, where 

 they have the name of " She Oaks," and on account of the 

 red and streaked appearance of their wood, also that of 

 Beefwood. Their sombre and drooping habit has caused 

 them to become favourites for ornamental trees in Australia, 

 being like weeping willows. C. equisetifolia is a native of 

 the sea-shores of the Indian Archipelago and South Sea 

 Islands, and is used for many purposes in the different 

 localities. Its hardness has obtained for it the name of Iron- 

 wood. The bark furnishes a dye, and the burnt ashes is 

 made into soap. It has a smooth bark, and even in the oldest 

 parts of the stem shows the ringed joints, while in C. torulosa 

 the stem is rough, with projecting corky bark divided by 

 deep furrows. Plants of it are cultivated in this country as 

 curiosities, and several old specimens at Kew have attained 

 the height of twenty feet. 



CLASS v.— RHIZOGENS. 



Fleshy, fungus-like, leafless parasites, growing on 

 roots, trailing stems, or branches of trees. Flowers in- 

 complete (consisting of calyx only), unisexual or bi- 

 sexual, solitary, conspicuous, and composing the whole 

 plant; or inconspicuous and numerous in heads or 

 spikes, produced from a fleshy, thallus-like rhizome. 

 Stamens few or many. Seeds small, chiefly microscopic, 

 some like spores of Cryptogams ; their mode of germi- 

 nation unknown. 



This singular class of plants consists of about 50 

 species, all widely distributed throughout the tropical 

 and sub-tropical regions of both hemispheres, their 

 southern limit being New Zealand, and their northern 

 the European coasts of the Mediterranean. The general 

 appearance and foetid odour of many of them originally 

 led to the supposition that they were related to fungi. 



