''Caladenia stellata'', commonly known as the starry spider orchid, is a plant in the orchid family Orchidaceae and is endemic to south-eastern

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. It is a ground orchid with a single, hairy leaf and usually only one greenish-cream flower with red markings.

Description

''Caladenia stellata'' is a terrestrial, perennial, deciduous,

herb In general use, herbs are a widely distributed and widespread group of plants, excluding vegetables and other plants consumed for macronutrients, with savory or aromatic properties that are used for flavoring and garnishing food, for medicinal ...

with an underground tuber. It has a single, dull green, hairy, linear leaf, 60–150 mm long and 5–10 mm wide with reddish-purple blotches near its base. Usually only one flower about 40 mm across is borne on a spike 120–300 mm tall. The flowers are greenish cream and the

sepals A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 The term ''sepalum'' was coined b ...

have thick, dark red, club-like glandular tips 5–10 mm long. The dorsal sepal is erect, 25–40 mm long, 1–3 mm wide and curves gently forwards. The lateral sepals are 26–40 mm long and 2–4 mm wide and spread widely, curving slightly downwards. The

petal Petals are modified Leaf, leaves that surround the reproductive parts of flowers. They are often advertising coloration, brightly colored or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''c ...

s are 20–30 mm long, about 2 mm wide and curve downwards. The labellum is 12–18 mm long, 7–13 mm wide, and greenish-cream with a dark red tip. The sides of the labellum turn upwards, the tip is curled under and there are six to eight short linear teeth on each side. There are four rows of dark red, club-shaped calli along the mid-line of the labellum. Flowering occurs from August to October.

Taxonomy and naming

''Caladenia stellata'' was first formally described in 1991 by David Jones and the description was published in ''Australian Orchid Research''. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

(''stellata'') is a Latin word meaning "starry", referring to the star-like spreading of the lateral sepals and petals.

Distribution and habitat

The starry spider orchid occurs in New South Wales south from Rankins Springs and in eastern South Australia where it grows usually grows in ''

Callitris ''Callitris'' is a genus of coniferous trees in the Cupressaceae (cypress family). There are 16 recognized species in the genus, of which 13 are native to Australia and the other three (''C. neocaledonica, C. sulcata'' and ''C. p ...

'' woodland. The South Australian plants may belong to a separate species.

Ecology

Males of the wasp species '' Phymatothynnus nitidus'' have been shown to be the pollinator of this orchid when they attempt to mate with the flower.

References

{{Taxonbar, from=Q9673974 stellata Plants described in 1991 Endemic orchids of Australia Orchids of New South Wales Taxa named by David L. Jones (botanist)