Australia

Some eucalypts range among the tallest-growing trees of the world, ten times taller than this glasshouse. The genus Eucalyptus is a large genus of Myrtaceae with over 600 species. The best known is perhaps the blue gum Eucalyptus globulus (used to distill eucalipt oil from its leaves). Smaller species of shrubby growth (called "mallees" in Australia) are better suited for display here. They show their partly conspicuous red or yellow flowers readily. Other Myrtaceae, a very important family in Australia, are the willow-like Agonis flexuosa and several species of Melaleuca, among them the paperbark tree, Melaleuca cuticularis.

Another important genus with remarkably diverse foliage is Acacia. At first sight and without flowers and fruits one would never suspect so different looking species like Acacia melanoxylon, A. baileyi, A. verticillata, A. alata, and A. cultriformis to belong to the same genus. One may add Acacia lasiocarpa and A. calamifolia, which are temporarily on display in House L, as good examples of an extremely broad range of leaf shapes with one single genus.

Another striking example of "simulators" is the family Casuarinaceae. The stems of Casuarina and Allocasuarina look much like Equisetum and neatly fit in to a series of examples of convergences already discussed in House L. The ribbon bush, Homalocladium platycladum of the Polygonaceae with ribbon like stems is very similar to the legume Carmichaelia williamsii. Rubus squarrosus is another surprise with its leaves almost entirely reduced to the prickly midrib. Other conspicuous plants in this house are Cordyline australis and the large agave-like rosettes of Doryanthes palmeri, which take 10-20 years from seed to flower. Photo right: Acacia.

Banksia integrifolia in the south corner of the house is already impressive by its gnarled trunk. Other species of Banksia are more successfully grown in the nursery and put on display here only when they flower. Photo left: Banksia.

B. Leuenberger