General Description:

Caleana is a genus of about 14 species all of which occur in Australia with one species (C.minor) extending to New Zealand.  Most species are found in Western Australia – note, however, that the Western Australian herbarium lists the 13 species in that state as being in the genus Paracaleana, but this classification is not recognised in the Australian Plant Census which ANPSA recognises as tha authority of Australian plant taxonomy.

Caleana major is a perennial herb, having a single, narrow leaf about 150 mm high and 4 to 8 mm wide. Several reddish flowers occur on a thin stem during spring and sometimes extend into summer.  They are usually about 25 mm long and up to 8 mm wide and have a distinctive duck-like shape.  The flowers are pollinated by male thynnid wasps. They are attracted by pheromones emitted by the flowers which replicate those emitted by female wasps.  Plants become dormant in summer when they die back to an underground tuber.

Most Australian terrestrial orchids require specialised cultural needs and are cultivated mainly by orchid enthusiasts. Generally the plants are grown in pots in a freely draining, sandy mix. They require good air circulation in a protected position of about 50% sun during the growing period from autumn to spring. During this growing period the plants must not be allowed to dry out. After the leaves have turned brown in late spring to early summer the pots are allowed to dry out completely. Repotting of tubers can be carried out in summer. Caleana major has proved to be difficult to maintain in cultivation for an extended period.

For further information on terrestrial orchid cultivation see Australia’s Native Orchids by Les Nesbitt.

Propagation of orchids requires specialised methods and is rarely attempted by the casual grower. The following references provide further information on growing terrestrial orchids from seed.

• Australian Terrestrial Orchids from Seed; D K McIntyre, G J Veitch and J W Wrigley
• A New Medium for Raising Australian Terrestrial Orchids from Seed; G J Veitch and D K McIntyre

Both articles appear in Australian Plants, journal of the Australian Native Plants Society (Australia), March 1973.