Cryptostylis is a
genusIn biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of
flowering plantThe flowering plants , also known as Angiospermae or Magnoliophyta, are the most diverse group of land plants. Angiosperms are seed-producing plants like the gymnosperms and can be distinguished from the gymnosperms by a series of synapomorphies...
s from the orchid family,
OrchidaceaeThe Orchidaceae, commonly referred to as the orchid family, is a morphologically diverse and widespread family of monocots in the order Asparagales. Along with the Asteraceae, it is one of the two largest families of flowering plants, with between 21,950 and 26,049 currently accepted species,...
. It was first defined by the prolific Scottish botanist,
Robert BrownRobert Brown was a Scottish botanist and palaeobotanist who made important contributions to botany largely through his pioneering use of the microscope...
in 1810. The type species has since been designated as
Cryptostylis erectaCryptostylis erecta, commonly known as the Bonnet Orchid or Tartan Tongue Orchid , is an orchid native to south eastern Australia....
. Other species include
Cryptostylis hunterianaCryptostylis hunteriana, commonly known as the Leafless Tongue Orchid grows in south eastern Australia. It is a rare species with a ROTAP rating of 3VC-...
and
Cryptostylis subulataCryptostylis subulata, known as the Large Tongue Orchid grows in south eastern Australia. It was given its current name by H.G. Reichenbach in 1871, originally described by Labillardiere as Malaxis subulata in 1806 from Tasmania. The specific epithet subulata refers to the duck like shape of the...
. Molecular study of their DNA shows the genus lies within the tribe Diurideae within the orchid family, having previously considered part of the Cranichideae. Together with the genus
CoilochilusCoilochilus is a genus of flowering plants from the orchid family, Orchidaceae.- References :*Pridgeon, A.M., Cribb, P.J., Chase, M.A. & Rasmussen, F. eds. . Genera Orchidacearum 1. Oxford Univ. Press....
they make up the subtribe Cryptostylidinae.
The genus comprises around twenty five species of terrestrial orchid distributed from southern Asia (specifically India and Sri Lanka) Thailand, Malaysia down through Indonesia and into Australia and New Zealand, as well as Samoa, New Caledonia, Vanauatu, the Philippines and Taiwan. Five species are found in Australia, of which three are endemic.
These orchids are single stemmed, either leafless or with one or more large leaves arising from the base of the stalk. The leaf undersides are often purple-hued, coloured with anthocyanin pigments. The flowers occur on
racemeA raceme is a type of inflorescence that is unbranched and indeterminate and bears pedicellate flowers — flowers having short floral stalks called pedicels — along the axis. In botany, axis means a shoot, in this case one bearing the flowers. In a raceme, the oldest flowers are borne...
s, with several found on one flower spike. The roots are
rhizomatousIn botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...
, but lack any
tuberTubers are various types of modified plant structures that are enlarged to store nutrients. They are used by plants to survive the winter or dry months and provide energy and nutrients for regrowth during the next growing season and they are a means of asexual reproduction...
ous structures.
All Australian species are pollinated by the
ichneumonIchneumonidae is a family within the insect order Hymenoptera. Insects in this family are commonly called ichneumon wasps. Less exact terms are ichneumon flies , or scorpion wasps due to the extreme lengthening and curving of the abdomen...
wasp known as the orchid dupe wasp (
Lissopimpla excelsaLissopimpla excelsa, commonly known as the orchid dupe wasp, is a Wasp of the family Ichneumonidae native to Australia. Although also found in New Zealand it has probably been introduced there. It pollinates all five Australian members of the orchid genus Cryptostylis . The male wasp mistakes the...
). The male wasp mistakes the flower parts for a female wasp and attempts to copulate with it. Although the different species can occur together, they appear to inhibit cross-fertilisation and no hybrids are found in nature. This discovery was made by Australian naturalist
Edith ColemanEdith Coleman was an australian naturalist who made important observations on pollination syndromes in Australian plant species.-References:*Allan McEvey, , Australian Dictionary of Biography, Volume 13, Melbourne University Press, 1993, p. 463....
in 1928, and the term coined was "
pseudocopulationPseudocopulation describes behaviors similar to copulation that serve a reproductive function for one or both participants but do not involve actual sexual union between the individuals. It is most generally applied to a pollinator attempting to copulate with a flower. Some flowers mimic a...
". The mimicking of flowers to resemble female wasp parts has since been recorded in other orchid genera. The flowers of
Cryptostylis orchids and female wasp body parts are very similar in colour when viewed under a
hymenoptera Hymenoptera is one of the largest orders of insects, comprising the sawflies, wasps, bees and ants. There are over 130,000 recognized species, with many more remaining to be described. The name refers to the heavy wings of the insects, and is derived from the Ancient Greek ὑμήν : membrane and...
n visual system, despite looking different to human eyes. Although the colours that ichneumon wasps see are unknown, bees and wasps have similar perception with green, blue and ultraviolet wavelengths.
The
Cryptostylis orchids are unusual in that several species are pollinated by the same wasp species; other orchids which mimic insects are often species-specific. The flowers have no smell detectable to humans, but have been shown to have an odour which attracts the orchid dupe wasp. Furthermore gas chromatography and electrophysiology show that the single active compound for pollinator attraction is found in different species of
Cryptostylis.