Key to Genera
KEY TO GENERA
† Treated in Vol. II. ζ See note below key.
Key
3
Land plants, or aquatics firmly rooted in soil with floating leaves or stems, or leaves raised above the water; leaves if narrow, not translucent
Aquatic plants, free-floating on surface of fresh water or rooted in soil and normally entirely submersed or intertidal; leaves mostly filamentous to ribbon-like, usually ± translucent
15
Inflorescence a panicle
SPORADANTHUS†
Inflorescence of distant spikelets towards stem-tip
EMPODISMA†ζ
18
Rhachilla not produced beyond utricle; flowers usually in several spikes but occasionally in a solitary spike
Rhachilla produced beyond utricle into a hook; flowers in a solitary spike
UNCINIA†
22
Inflorescence usually bracteate, terminal but often apparently lateral; nut without persistent style-base
Inflorescence ebracteate, terminal and appearing so; nut crowned by enlarged persistent style-base
23
Leaves harshly scabrid on margins and keel; style without basal hairs, continuous with nut
26
Stems terete; glumes spirally arranged
GAHNIA†
Persistent style-base ± = body of nut in length
31
Leaves similar to stems, or reduced to basal sheaths
LEPIDOSPERMA†
32
Leaf-sheaths hyaline, pale green or colourless; glume-like floral bracts 2, appearing opposite
Flowers solitary, or in panicles or cymes; perianth of 3 green sepals and 3 white, pink or yellow petals
48
Plants of sites below regular high tide mark, usually forming grass-like sward; leaves linear but not filiform, with numerous transverse veinlets at right angles to midrib and strong marginal nerves
Plants of brackish or fresh water; leaves usually distributed on slender stems, or, if closely crowded, almost filamentous, without numerous transverse veinlets and strong marginal nerves
49
Peduncles, long, thread-like, becoming spirally coiled as fruit matures; flowers 2, sessile and close together, each producing (2)–4–8–(16) obviously stalked achenes
Peduncles mostly short, never spirally coiled; flowers 1–many, each producing at most 4 sessile or obscurely stalked achenes
Leaves with stipules, sometimes sheathing; stem-internodes mostly easily visible, many >1 cm long
51
Flowers bisexual, tetramerous, many, in obvious, fully exserted, continuous or interrupted spikes
53
Roots absent; platelets deeply keeled
WOLFFIA†
54
Roots 1 per platelet
LEMNA†
58
Leaflets reduplicately inserted on axis (A-shaped in T.S.); trees monoecious; spathes subtending inflorescence2
RHOPALOSTYLIS†
Leaflets induplicately inserted on axis (V-shaped in T.S.); trees dioecious; spathe subtending inflorescence solitary
63
Leaves equitant
PHORMIUM†
71
Perianth-lobes with a conspicuous green or purple median vein; plant with fleshly-fibrous roots
Perianth-lobes variously coloured, blue, rose or white, without green median stripe; staminal-filaments filiform or dilated only at base
75
Perianth-tube fleshly or almost absent
ASTELIA†
85
Leaves ± fleshly or flaccid; fruit a capsule
ARTHROPODIUM†
Stem scarcely woody, almost entirely enclosed in leaves, midrib scabrid abaxially
DIANELLA†
98
Perianth-tube dilating gradually; upper perianth-lobes not hooded; spathe-valves herbaceous, green
Perianth-tube narrow-cylindrical in lower half, abruptly dilated at middle; upper perianth-lobe ± hooded; spathe-valves membranous brownish
103
Flowers white; outer perianth-lobes shorter and narrower than inner
LIBERTIA†
104
Style with short style-branches; flowers creamy-yellow with purple stripes or light violet-blue; base of leaf-fan light green
Style unbranched with 3 lobes at tip; flowers deep blue and base of leaf-fan bright reddish-purple
111
Plant with chlorophyll, tuberous and/or rhizomatous
ALSTROMERIA
117
Peduncle shorter than flower, lengthening in fruit; flower usually solitary
CORYBAS†
118
Flower usually solitary; labellum with many, ± clavate calli in longitudinal rows
ADENOCHILUS†
Flowers usually > 1; labellum without such rows of calli
ACIANTHUS†
119
Leaves and/or stem minutely hairy
CALADENIA†
120
Flower almost regular as to perianth; labellum little differentiated
THELYMITRA†
121
Labellum pendent from flower with conspicuous reddish beard
CALOCHILUS†
Labellum uppermost, its peltate tuberculate lamina attached by slender claw
CALEANA†
122
Dorsal sepal hooded; labellum below column
MICROTIS†
Dorsal sepal not hooded; labellum above column
PRASOPHYLLUM†
124
Leaves glandular-hairy; petals and sepals mostly white
APOROSTYLIS†
125
Leaves close together; peduncle < leaves at flower, lengthening in fruit rarely > 1 flower
CHILOGLOTTIS†
Leaves well spaced; peduncle much > leaves at flower, sometimes with leaf-like bract; often > 1 flower
LYPERANTHUS†
126
Flower solitary, or few in short inflorescence
PTEROSTYLIS†
127
Flowers always inverted so that labellum lies above column
CRYPTOSTYLIS†
128
Perianth-segments unequal; lateral sepals filiform, 1.5–3 cm long
ORTHOCERAS†
Perianth-segments subequal, rarely > 6 mm long
SPIRANTHES†
129
Flower solitary, barely emerging from litter
CORYBAS†
130
Sepals and lateral petals fused to form tube; rhizome 1–5 cm diam.
GASTRODIA†
Sepals and lateral petals free; rhizome rarely > 5 mm diam.
YOANIA†
131
Leaves mostly < 2.5 cm long, each attached to pseudobulb
BULBOPHYLLUM†
132
Stem very short, with crowded, ± oblong, distichous leaves
DRYMOANTHUS†
Stems usually unbranched; flowers many together
EARINA†
ζEmpodisma Johnson et Cutler (Kew Bull. 28, 1973, 383) was segregated from Calorophus Labill., which is now considered to be restricted to Tasmania. They summarised in a table the many differences in floral morphology and culm anatomy between the two genera. One sp. of Empodisma is endemic to S. W. Australia, the other, E. minus (Hook. f.) Johnson et Cutler based on Calorophus minor Hook. f., is widespread in S. E. Australia, Tasmania and N.Z.
