Those that grow on rock or in rock crevices are described as being lithophytes. An example of such a plant is Dendrobium kingianum, an orchid which belongs to the second-largest family of flowering plants on Earth.
This orchid is endemic to eastern Australia between New South Wales and Queensland and has a tendency to grow on rocks, often clinging on to cliff faces. It is usually seen in large colonies spreading over several metres.
D. kingianum has spongy white roots that have adapted to cling to rock surfaces and to absorb water quickly.
This orchid’s stems have thickened sections known as pseudobulbs, which are succulent and used by the plant to store water over the dry winter months.
Its beautiful pink flowers usually appear from August to October and shoot out on a raceme that is between eight to 16cm in length, bearing up to 15 flowers on a single stem.
Dunedin’s climate is not suitable to grow exotic species of orchids outside, although with protection or a suitable microclimate, it is still possible to grow this beautiful plant here.
It grows best in warm sunny positions on bark, fixed to a rock or in a free-draining potting mixture of woodchip, pearlite and river pebbles.
Its growing period is from August through to March so now is the right time for establishing new plants.
Garden Life is produced by the Dunedin Botanic Garden. For more information contact Ruben Scarlett-McRae.
