Cyanicula Caerulea

''Cyanicula'', commonly known as blue orchids, is a genus of twelve species of plants in the orchid family, Orchidaceae. All are endemic to Australia, eleven are endemic to Western Australia and one species occurs in eastern Australia. While both the common and scientific names refer to "blue", the two subspecies of '' C. ixioides'' have yellow or white flowers. They are similar to orchids in the genus ''Caladenia'' but differ in their flowers colour and in other important ways.

Description

Orchids in the genus ''Caladenia'' are terrestrial, perennial, deciduous, sympodial herbs with a few inconspicuous, fine roots and a tuber partly surrounded by a fibrous sheath. Unlike orchids in the genus ''Caladenia'', the tuber does not produces "droppers" - instead replacing itself within the same cavity. There is a single hairy convolute leaf at the base of the plant. Unlike the hairs on caladenia leaves, the hairs do not have an enlarged cell at their base. The leaf is linear to egg-shaped, fleshy or leathery, lance-shaped to oblong, but is always simple, lacking lobes and serrations.

The inflorescence is a raceme with up to three resupinate flowers. The three sepals and two petals are free and similar in size and shape to each other. As is usual in orchids, one petal is highly modified as the central labellum. The labellum is usually divided into three parts, each of which usually has a fringed or dentate margin, while the central lobe has stalked or button-like calli which are sometimes in rows. The sexual parts of the flower are fused to the column, which has wing-like structures on its sides. Flowering occurs in spring, although more prolifically after fires the previous summer. The fruit that follows flowering is a non-fleshy, dehiscent capsule containing up to 500 seeds.

Taxonomy and naming

James Drummond noticed the different tubers of some orchids and suggested that those that did not produce "droppers" be placed in a separate genus. When John Lindley and others reviewed ''Caladenia'', they placed ''Caladenia gemmata'' in ''Caladenia'' Section ''Pentisia''. On the basis of molecular phylogenetics studies, in 2000 Stephen Hopper and Andrew Brown formally described the genus ''Cyanicula'' in ''Lindleyana'' and nominated '' Cyanicula gemmata'' as the type species.

The name "Cyanicula" is derived from the Ancient Greek word ''cyano-'' meaning "blue" and the suffix ''-icula'' meaning "small" referring to the small, (usually) blue flowers of this genus.

Plants of the World Online lists ''Cyanicula'' as a synonym of ''Caladenia''.

Distribution and habitat

The Western Australian species of ''Cyanicula'' occur throughout the south-west of the state, from as far north as Kalbarri to as far east along the south coast as Israelite Bay. In eastern Australia, '' Cyanicula caerulea'' occurs in New South Wales, Queensland and Victoria. In New South Wales, '' C. caerulea'' occurs in coastal regions, on the tablelands south from Torrington and on the western slopes of the ranges. Blue orchids are found in a variety of habitats from winter-wet swamps and the margins of salt lakes to stony soils in woodland.

*'' Cyanicula amplexans'' ( A.S.George) Hopper & A.P.Br. - WA
*'' Cyanicula aperta'' Hopper & A.P.Br. - WA
*'' Cyanicula ashbyae'' Hopper & A.P.Br. - WA
*'' Cyanicula caerulea'' ( R.Br.) Hopper & A.P.Br. - Qld NSW Tas Vic
*'' Cyanicula fragrans'' Hopper & A.P.Br. - WA
*'' Cyanicula gemmata'' (Lindl.) Hopper & A.P.Br. - WA
*'' Cyanicula gertrudiae'' ( Ostenf.) Hopper & A.P.Br. - WA
*'' Cyanicula ixioides'' (Lindl.) Hopper & A.P.Br. - WA
** ''Cyanicula ixioides'' Lindl. subsp. ''ixioides'' - WA
** ''Cyanicula ixioides'' subsp. ''candida'' Hopper & A.P.Br. - WA
*'' Cyanicula nikulinskyae'' Hopper & A.P.Br. - WA
*'' Cyanicula sericea'' (Lindl.) Hopper & A.P.Br. - WA
* ''Cyanicula'' sp. 'Dale' - WA
* ''Cyanicula'' sp. 'Esperance' - WA

References

{{Taxonbar, from=Q1621793

Orchids of Australia
Diurideae genera