Common Name: Helmet orchids
Synonyms: Anzybas D.L.Jones & M.A.Clem. APNI*
Calcearia Blume APNI*
Corysanthes R.Br. APNI*
Nematoceras Hook.f. APNI*
Gastrosiphon M.A.Clem. & D.L.Jones APNI*
Molloybas D.L.Jones & M.A.Clem. APNI*
Singularybas Molloy, D.L.Jones & M.A.Clem. APNI*
Description: Terrestrial herbs, sympodial. Leaf solitary, circular to cordate, sometimes lobed.
Flower solitary, sessile or shortly pedicellate, usually reddish or purplish, dominated by the dorsal sepal and labellum. Dorsal sepal erect and incurved, expanded gradually or with a distinct basal claw. Lateral sepals linear to filiform, free or fused at the base. Petals linear to filiform, often auriculate at the base. Labellum either tubular throughout with an apical orifice or with a basal tube and expanded lamina, with or without a central boss; labellum tube with basal auricles either open or closed. Column much reduced, enclosed by the base of the labellum tube.
Distribution and occurrence: World: c. 100 species, Asia, Malesia, Australia, Polynesia & Macquarie I. Australia: 20 species (19 species endemic), all States except N.T.
We have chosen not to recognise the following genera segregated from, or resurrected from synonymy under Corybas by Jones et al. (2002, Orchadian 13: 437-468): Anzybas, Calcearia, Corysanthes, Gastrosiphon, Molloybas, Nematoceras, Singularybas. Those authors justified recognition of these genera on the grounds that their phylogenetic analysis (Clements et al. 2002, Lindleyana 17: 135-171) showed these taxa all to be monophyletic. However, they neglected to mention that Corybas, as formerly and broadly circumscribed, was also shown by their analysis to be monophyletic. The numerous name changes that they proposed for Corybas are simply unnecessary. (P.H. Weston March 2007)
Text by D. L. Jones, key updated by Matt AM Renner (17 March 2021)
Taxon concept: D. L. Jones (1993, Flora of New South Wales volume 4)
Taxa not yet included in identification key
Corybas diemenicus,
Corybas montanus,
Corybas x dowlingii
| | Key to the species | |
| 1 | Dorsal sepal with a narrow basal claw suddenly expanded to the lamina; labellum tubular throughout with a terminal orifice | 2 |
| Dorsal sepal expanded gradually to the lamina; labellum tubular only at the base then expanded to an open lamina | 4 |
| 2 | Dorsal sepal longer than labellum; flowers distinctly banded | Corybas fordhamii |
| Dorsal sepal as long as or shorter than labellum; flowers uniformly coloured
Back to 1 | Corybas unguiculatus |
| 4 | Auricles at the base of the labellum tube remaining closed | 5 |
| Auricles at the base of the labellum tube open at the apex
Back to 1 | 7 |
| 5 | Dorsal sepal not obscuring labellum; labellum apex with a short tail | Corybas undulatus |
| Dorsal sepal obscuring most of the labellum; labellum apex without a tail
Back to 4 | 6 |
| 6 | Flowers white to pinkish | Corybas barbarae |
| Flowers reddish grey to reddish purple
Back to 5 | Corybas aconitiflorus |
| 7 | Labellum boss notched in the upper margin | 8 |
| Labellum boss entire
Back to 4 | 9 |
| 8 | Labellum margins coarsely toothed | Corybas hispidus |
| Labellum margins entire or finely toothed
Back to 7 | Corybas incurvus |
| 9 | Labellum tube shorter or as long as the lamina | 10 |
| Labellum tube longer than lamina
Back to 7 | 11 |
| 10 | Labellum tube much shorter than lamina | Corybas fimbriatus |
| Labellum tube about as long as lamina
Back to 9 | Corybas pruinosus |
| 11 | Flower 18–24 mm long, dark reddish with a conspicuous white labellum boss | Corybas dilatatus |
| Flower 12–16 mm long, pale reddish pink, with an inconspicuous off-white labellum boss
Back to 9 | Corybas longitubus |
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