Thelymitra is a genus of about 80 species of terrestrial orchids distributed throughout Australia, New Zealand and islands to the north of Australia. They are known as “sun orchids” because the flowers of most species only open fully on warm, sunny days.
Thelymitra ixioides is a widespread species comprising two recognised varieties, the main differences being:
- I.ixioides var. ixioides – mauve sepals and petals.
- I.ixioides var. subdifformis – greenish sepals and mauve petals.
The plant has deeply channelled leaves which are long and lance-shaped. Between 2 and 8 flowers about 2.5 cm in diameter occur on a slender stem up to 60 cm high. The flowers are bright blue or mauve (rarely pink or white) covered with dark spots. Flowering occurs in spring and the plants become dormant in summer when they die back to an underground tuber.
As I.ixioides has fairly specialised cultural needs (like most terrestrial orchids) it is 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.
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.
Photo: Jill Dark