98 AUSTRALIAN TREES AND SHRUBS. 



manna is obtained from one species, and a cool, refreshing 

 drink is yielded by the cider gum of Tasmania. The young 

 branches and leaves of most gum trees are more or less covered 

 \vith pellucid dots marking the position of oil glands. It is 

 the oil in the leaves that gives the Eucalypts their distinctive 

 odour. The name Eucalpytus is derived from eu, well, and 

 kalypio, to cover, as with a lid. This is in reference to the 

 flower. Before expansion the stamens are covered with a 

 cap which afterwards falls off in one piece in the shape of a 

 lid or cover. It is worthy of remark that although the 

 largest of trees, reaching to a height of over three hundred 

 feet, the gum trees have very small, even minute, seeds. The 

 flowers are produced in the axils of the leaves either singly 

 or in clusters varying from three to fifteen flowers. The calyx 

 is of a firm texture and separates into two parts, the upper 

 part, as already mentioned, which resembles a lid or cover, 

 falls away in a single piece, while the lower part is persistent 

 and bears very numerous stamens forming a fringe round its 

 summit. The majority of the flowers of Eucalyptus have 

 white and cream-coloured stamens. Those with very showy 

 crimson or yellow stamens are mostly confined to Western 

 and tropical Australia. In one instance the iron bark has 

 sometimes pink and sometimes crimson stamens. In 

 Western Australia there are gum trees with bright yellow 

 stamens, and others with beautiful red stamens, while one 

 has orange -coloured stamens. In the thick and woody walls 

 of the capsules of Eucalyptus we have a remarkable provision 

 for protection against desiccation during the long periods of 

 drought which occur in Australia. As, however, no rain falls 

 when the trees are in flower the pollen is quite unprotected, 

 and the numerous stamens, often a hundred or more, are 

 completely exposed. There is a further remarkable 

 adaptation to environment in the case of the leaves. The 

 leaf-blades in adult trees are not set horizontally like those 

 of the ordinary broad-leaved trees in this country ; but by 

 the twisting of their stalks, they are set vertically. This is a 

 provision to lessen evaporation in the dry climate of Australia, 



