1	"Plants terrestrial (rarely on tree-fern trunks), above-ground parts usually annual; leaves often membranous"	2
1	"Plants epiphytic or lithophytic, perennial; leaves rather tough"	31
2	"Labellum above the column in mature flowers (non-resupinate)"	3
2	"Labellum below the column in mature flowers (resupinate)"	8
3	"Labellum on a movable, slender, strap-like claw (articulate on column-foot), lamina attached by lower surface (not margin)"	4
3	"Labellum claw very short and inconspicuous, lamina attached by margin"	5
4	"Leaves absent; column with wing-like auricles above the middle; labellum lamina narrow, fringed with hairs"	"Thynninorchis {Thynninorchis huntiana}"
4	"Leaves present, often reddish; column broadly winged for its entire length; labellum lamina ovate to ovoid, lacking marginal hairs"	Caleana
5	"Labellum more than 1.5 cm long, much larger and broader than all other segments; leaves ovate to elliptic or absent"	Cryptostylis
5	"Labellum less than 1.5 cm long, about as long as other segments; leaf tubular and stem-encircling for much of its length or absent"	6
6	"Leaves absent; flowers pendent on a distinct pedicel, brown and white, bell-like with all segments fused in basal half"	Gastrodia
6	"Leaf present; flowers not pendant, more or less sessile, variously coloured, at least some perianth segments totally free"	7
7	"Perianth segments usually < 7 mm long; leaf sheath opening into lamina near to base of inflorescence; labellum on a movable claw; flowers mainly autumn"	Corunastylis
7	"Perianth segments usually > 7mm long; leaf sheath opening into lamina well below inflorescence; labellum not on a movable claw; flowers mainly spring"	Prasophyllum
8	"Perianth segments less than 5 mm long"	9
8	"Perianth segments more than 5 mm long"	11
9	"Leaf solitary, round in cross-section, surrounding much of scape"	Microtis
9	"Leaves several, linear, mostly free from scape"	10
10	"Dorsal sepal with a prominent backward-pointing spur at base; flowers arranged in an indistinct spiral, mostly reddish-brown and yellow"	Disa
10	"Dorsal sepal without a spur at base; flowers usually arranged in a distinct spiral, pink with a white labellum, rarely all white"	Spiranthes
11	"Flowers green or reddish with colourless 'windows'; dorsal sepal and petals adhering for their entire length forming a galea; labellum small and mobile; leaves usually several per plant, sometimes withered at flowering"	Pterostylis
11	"Combination of characters not as above"	12
12	"Flowers usually entirely reddish or purplish; dorsal sepal and immobile labellum enlarged and more or less cohering; other perianth segments minute; leaf solitary"	Corybas
12	"Combination of characters not as above"	13
13	"Perianth almost actinomorphic; labellum very similar to all other perianth segments"	Thelymitra
13	"Perianth zygomorphic; labellum usually much modified and different from other perianth segments"	14
14	"Lateral sepals either much larger or much narrower than dorsal sepal"	15
14	"Lateral sepals not markedly different in shape and length from dorsal sepal"	18
15	"Lateral sepals much larger than all other segments, white or pink; labellum much recurved in distal half"	Eriochilus
15	"Lateral sepals much narrower and longer than dorsal sepal, brown or greenish; labellum not recurved in distal half"	16
16	"Leaf solitary (rarely 2), ovate; labellum with wide, reddish-purple fringe"	"Leporella {Leporella fimbriata}"
16	"Leaves 2 or more, linear; labellum-margins entire"	17
17	"Petals large and well-developed, pedicellate; lateral sepals deflexed, narrow; flowers pedicellate"	Diuris
17	"Petals minute, sessile, erect or upcurved, hidden within the dorsal sepal; lateral sepals erect, extremely long and thread-like; flowers sub-sessile"	"Orthoceras {Orthoceras strictum}"
18	"Labellum longer than all other segments, densely covered with brown to reddish-hairs or papillae (except in C. imberbis)"	Calochilus
18	"Labellum no longer than other segments, usually shorter, indumentum not as above"	19
19	"Plants with basal leaves or large leafy bracts at some stage of development"	20
19	"Plants lacking basal leaves and large cauline leafy bracts at all stages of development, basal bracts sometimes present"	30
20	"Leaf solitary; labellum entirely smooth (1 or 2 glands or calli sometimes at extreme base)"	21
20	"Leaves 1 or 2; labellum variously fringed, hairy and/or with lamina glands or calli"	23
21	"Leaf very hairy; flower usually solitary, bright mauve or purplish, rarely white; column broadly winged throughout"	Glossodia
21	"Leaf glabrous; flowers usually several, greenish-brown or dark red; column almost wingless or winged in upper part only"	22
22	"Leaf heart-shaped, often held well above soil surface, reddish-purple to green beneath, not glistening; perianth segments with fine extension; column very narrowly or not winged"	Acianthus
22	"Leaf orbicular, ground-hugging, with light green glistening undersurface; perianth segments not tapering to long fine point; column prominently winged in upper part"	Cyrtostylis
23	"Leaves 2; flower solitary, green or reddish-brown; labellum entire, with few to many dark waxy calli"	Chiloglottis
23	"Leaf solitary; flowers often more than 1; labellum tri-lobed, sometimes obscurely so, with many lamina calli, usually in rows"	24
24	"Leaf variously hairy"	25
24	"Leaf glabrous"	28
25	"Perianth segments variously coloured, but not blue or purplish"	Caladenia
25	"Perianth segments blue or purplish"	26
26	"Labellum distinctly tri-lobed, lamina with 2 neat rows of calli"	"Cyanicula {Cyanicula caerulea}"
26	"Labellum obscurely tri-lobed, lamina with 4–8 rows of congested calli or with many scattered calli"	27
27	"Labellum not usually white at base, lacking tall calli at base, lamina with 4–8 rows of congested calli"	"Pheladenia {Pheladenia deformis}"
27	"Labellum often white towards base, lamina with 2 or 4 tall calli at base and many small scattered calli (natural hybrid between Pheladenia and Glossodia)"	"×Phelodia {xPhelodia tutelata}"
28	"Petals and lateral sepals dimorphic; floral bracts small, not exceeding ovaries; column broadly winged; labellum on a moveable claw"	"Leptoceras {Leptoceras menziesii}"
28	"Petals and lateral sepals similar in size, shape and colour; floral bracts large, exceeding ovaries; column wings very narrow or rudimentary; labellum sessile"	29
29	"Leaf broad-ovate to sub-orbicular, fleshy, ground-hugging; flowers white with prominent red stripes, drying black"	"Pyrorchis {Pyrorchis nigricans}"
29	"Leaf linear-lanceolate, thin-textured, obliquely erect; flowers usually dark brown with red and yellow markings, not drying black"	"Lyperanthus {Lyperanthus suaveolens}"
30	"Plants robust, often up to 1 m tall; flowers usually heavily spotted or blotched; plants not fire-dependant for flowering"	Dipodium
30	"Plants slender, <15 cm tall; flowers not spotted or blotched; plants flowering only the season following a fire"	"Burnettia {Burnettia cuneata}"
31	"Leaves thick-textured, ovate or terete; lateral sepals dilated at base and united with column foot to form a chin-like extension; labellum without spur; plants lithophytic"	Dendrobium
31	"Leaves thin-textured, lanceolate, often falcate; lateral sepals free, not forming chin-like extension; labellum with prominent spur or deep pouch; plants epiphytic"	32
32	"Roots mostly hanging in the air and very long; perianth less than 6 mm long; spur of labellum hollow, with finger-like appendage almost closing orifice"	"Plectorrhiza {Plectorrhiza tridentata}"
32	"Roots mostly creeping on bark of host; perianth more than 10 mm long; labellum solid, without appendage"	Sarcochilus