Thelymitra Antennifera

''Thelymitra antennifera'', commonly called the rabbit-eared sun orchid, lemon-scented sun orchid or vanilla orchid is a species of orchid which is native to Western Australia, South Australia and Victoria and northern parts of Tasmania.

''Thelymitra antennifera'' is the emblem of the Peninsula Field Naturalists Club (Mornington Peninsula, Victoria). It was chosen as the club's emblem as it was once common in the area around Frankston, but is now rare.

Description

''Thelymitra antennifera'' is a tuberous, perennial herb, 10–25 cm tall with yellow flowers from July to October. Its leaf is circular in cross–section, 5 to 12 cm long and 2 to 3 mm wide. The inflorescence consists of one to four yellow flowers on a wiry, zig-zagged often pinkish stem. Each flower is 20 to 40 mm across with a lemon or vanilla scent. The sepals and petals are 12 to 20 mm long and 4 to 6 mm wide, the sepals having a broad, reddish–brown band on their outer surface. The column is 5 to 6 mm long and 2 to 3 mm wide with dark brown arms that are ear-like and held high above the column. As with others in the genus, it reproduces by seeds but is unusual in that it is one of the few that develops tubers on the end of stolon-like roots, allowing it to form new colonies. The flowers are insect pollinated and open readily, even on cool days and are long-lasting.

Distribution and habitat

The species occurs in the South–West and Eremaean botanical provinces of Western Australia. It is also found South Australia and Victoria. In Tasmania it only occurs in a few small areas and is classified as an endangered species in that state. Elsewhere it is widespread and common, growing in many habitats, especially shrub, heath and mallee. It sometimes forms dense, extensive colonies, flowering freely, especially after fire.

Taxonomy and naming

The species was first described by John Lindley in 1840 in his ''A Sketch of the Vegetation of the Swan River Colony'' (1840) as ''Macdonaldia antennifera''. but was later renamed ''Thelymitra antennifera'' by the English botanist Joseph Dalton Hooker in ''The botany of the Antarctic voyage of H.M. discovery ships Erebus and Terror. III. Flora Tasmaniae'' The specific epithet (''antennifera'') is from the Latin ''antenna'', (classically "a sail yard"), and ''-fer'' meaning "-bearing", referring to the lateral appendages on the column. The genus name ''Macdonaldia'', honours "Mrs. Smith, ''née'' Macdonald, a lady who has examined the Orchidaceous plants of that island with great care, and from whom a most beautiful series of dried specimens has reached me through the offices of Mr. Gunn".

Five hybrids are recognised–
* ''Thelymitra antennifera'' (Lindl.) Hook.f. x '' Thelymitra gregaria'' D.L.Jones & M.A.Clem.
* ''Thelymitra antennifera'' (Lindl.) Hook.f. x '' Thelymitra luteocilium'' Fitzg.
* ''Thelymitra antennifera'' (Lindl.) Hook.f. x ''Thelymitra macrophylla'' Lindl. crimson sun orchid
* ''Thelymitra antennifera'' (Lindl.) Hook.f. x '' Thelymitra maculata'' Jeanes western wheatbelt sun orchid
* ''Thelymitra antennifera'' (Lindl.) Hook.f. x '' Thelymitra vulgaris'' Jeanes scarce sun orchid

Use in horticulture

Thelymitra species are readily cultivated in pots.

References

{{Taxonbar, from=Q10946630

antennifera
Endemic orchids of Australia
Orchids of Western Australia
Plants described in 1840
Taxa named by John Lindley