Citation: R. Br., Prod. Fl. Nov. Holl. 323 (1810).

Derivation: Greek kalos, beautiful; aden, a gland.

Synonymy: Not Applicable

Common name: Spider-orchids.

Description:
Terrestrial herbs, generally very hairy, but sometimes only slightly so, originating from rounded tunicated tubers, the more recent tubers generally below those of previous seasons; leaf more or less hairy (except in C. menziesii), solitary, elongate, generally linear-lanceolate or oblong, from within a scarious sheathing scale close to the ground.

Flowers solitary, or in a loose raceme of (apparently) not more than 10, on an erect scape with an empty bract or sheathing scale about the middle and a similar bract under each pedicel; flowers resupinate, usually erect and variously coloured; dorsal sepal erect, incurved over the column or more rarely retracted, usually narrow; lateral sepals nearly equal to it but flat, spreading or reflexed; petals narrow, erect, spreading or reflexed; labellum often on a movable claw and generally erect at the base, undivided or 3-lobed; the lateral lobes when present erect; the middle lobe or distal part of the undivided labellum recurved; the margins often fringed or toothed; the lamina with sessile or stalked calli arranged in 2 or more longitudinal rows or irregularly scattered or crowded; column erect or incurred, more or less winged in the upper part, at the base of the column often 2 yellow sessile glands; anther terminal, more or less oblique, usually pointed, 2-celled, valvate; pollinia 4, lamellar, commonly narrow-ovate, 2 free masses in each cell, granular; stigma immediately below the anther, circular and disc-like; rostellum poorly developed; viscid disk and caudicle absent.

Distribution:  A rather large genus comprising over 70 species. (The species with a long-tailed perianth are commonly known as spider orchids). All are endemic to Australia with the exception of C. lyallii which also occurs in New Zealand and C. carnea which is also recorded from New Zealand, New Caledonia, Indonesia and Malaysia.

Biology: Colourfully flowered species are pollinated mainly by bees, the maroon- and green-flowered species by sexually attracted thynnid male wasps.

Key to Species:

1. Leaf glabrous; petals dark-reddish, c. 20 mm long, about twice as long as the pink and white sepals	C. menziesii 16.
1. Leaf pubescent
2. Base of the column without a pair of glands
3. Perianth-segments (except the labellum) tapering into glandular-filiform tips (caudae)
4. Perianth-segments c. 50 mm long	C. filamentosa 9.
4. Perianth-segments less than 30 mm long	C. bicalliata 1.
3. Perianth-segments not tapering into glandular-filiform tips
5. Labellum distinctly 3-lobed, bearing 2-4 rows of calli
6. Calli arranged in a semicircle at the bend of the labellum or in 2 converging rows; leaf oblong-lanceolate, more than 5 mm wide	C. latifolia 14.
6. Calli in regular longitudinal rows; leaf linear, less than 5 mm wide
7. Calli in 4 or 6 rows
8. Calli in 4 rows; dorsal sepal hooded over the column and both conspicuously bent forward	C cucullata 6.
8. Calli in 6 rows; dorsal sepal spreading or erect like the column	C. deformis 7.
7. Calli in 2 rows
9. Mid-lobe of labellum long-acuminate, entire, completely covered by 2 rows of tightly packed reddish-black calli	C. congesta 5.
9. Mid-lobe of labellum not acuminate, apex free of calli, basally with white- or yellow-headed calli
10. Column and labellum barred with dark-red	C. carnea 3.
10. Column not barred; labellum barred or not with dark-red
11. Labellum not barred; perianth-segments white; sepals more than 1 cm long	C. carnea 3.
11. Labellum barred with dark-red; perianth-segments pink, occasionally with deep-red tints; sepals less than 1 cm long	C. pusilla 19.
5. Labellum indistinctly lobed
12. Calli in 2 distinct rows at the base of the labellum, less regular towards the tip	C. x tutelata 23.
12. Calli in 4-6 ill-defined rows, giving a very hirsute appearance
13. Dorsal sepal radiating like the other perianth-segments (except labellum); segments blue (rarely white); calli long-papillate, in 4 rows on the lower half of the labellum	C. deformis 8.
13. Dorsal sepal hooded over the column; perianth-segments dark outside, white with pink tips inside; calli clubbed, in 4 rows and reaching almost to the tip of the labellum	C. gracilis 12.
2. Base of the column with 2 sessile yellow glands
14. Margins of the labellum entire or slightly toothed apically; perianth-segments 2-3 cm long, spreading radially except the dorsal sepal which is hooded over the column; sepal tips various
15. Sepals shortly acuminate, tips not glandular or clavate; calli congested in 2-4 rows in the lower two-thirds of the labellum	C. cardiochila 2.
15. Sepal tips glandular-clavate
16. Petal tips glandular or clavate; labellum ovate; calli in 4 rows, various
17. Perianth-segments with filiform not dilated tips	C. toxochila 22.
17. Perianth-segments with bayonet-like dilated tips	C. gladiolata 11.
16. Petal tips not glandular nor clavate
18. Labellum oblong to broad-linear, c. 2-3 times as long as wide (11-13 x c. 4.5 mm), the margins practically entire, wholly dark-purplish, with 4 rows of minute sessile calli towards the base	C. leptochila 15.
18. Labellum cordate or ovate, less than 3 times as long as wide (9-11 x 8-11 mm), margins entire or serrulate
19. Labellum cordate; lateral lobes greenish or yellowish, entire, veins hardly visible; calli flat-roped, in 4 rows	C. clavigera 4.
19. Labellum ovate; lobes purplish; veins dark, divergent; calli in 2 or 4 rows, generally small and mammillary	C. ovata 17.
14. Margins of the labellum serrate or comb-like; perianth-segments caudate, generally drooping; sepals glandular-tipped
20. Petals conspicuously glandular-tipped
21. Labellum 1.5-2 cm long; calli in 4-6 rows, linear-clubshaped, loose	C. patersonii 18.
21. Labellum to 1 cm long; calli in 4-8 rows, squarish, rather stout and short, imbricate	C. x variabilis 24.
20. Petals not glandular-tipped
22. Labellum obscurely lobed, ovate-cordate, to 20 mm long.	C. dilatata 8.
22. Labellum not lobed, ovate, 9-13 mm long
23. Labellum lamina and apex pure white; perianth-segments cream-white, glandular tips c. 10 mm long	C. rigida 21.
23. Labellum lamina red or with a red apex or red markings; perianth-segments yellowish-green to crimson
24. Labellum with conspicuous dark divergent veins which end in long crimson linear teeth; glandular tip on sepals often to 10 mm long	C. reticulata 20.
24. Labellum without conspicuous veins, but usually with a maroon tip; margins dentate; glandular tip on sepals c. 5 mm long
25. Labellum ovate-acute; lamina flat; leaves 8-20 mm wide	C. fitzgeraldii 10.
25. Labellum appearing cordate, lamina hollowed by gently incurved margins; leaves 3-6 mm wide	C. aff.huegelii 13.

Author: Not yet available