1	"Corolla lobes in open flowers erect, inflexed, or ascending at more than 45º"	2
1	"Corolla lobes in open flowers spreading at less than 45º or recurved or revolute"	11
2	"Leaves with the secondary and smaller veins obscure on the lower surface or almost so, faintly visible on the upper surface; older stems with prominent corky outgrowths"	"Parsonsia rotata"
2	"Leaves with secondary veins distinct and raised on the lower surface; stems without corky outgrowths"	3
3	"Corolla quite glabrous internally"	4
3	"Corolla bearded inside at base of lobes or in throat"	5
4	"Leaves with only the secondary veins and midvein prominent, a few coarse net veins often visible, variable in shape, usually 3–9 cm long; corolla 4–5.5 mm long"	"Parsonsia lanceolata"
4	"Leaves with the main net veins distinct, as well as the secondary veins and midvein, 6–11 cm long; corolla 7.2–9.5 mm long"	"Parsonsia kimberleyensis"
5	"Leaves on adult plants conspicuously cordate at base"	6
5	"Leaves on adult plants rounded, truncate or cuneate (or sometimes slightly cordate in P. grayana) at base"	7
6	"Petiole 10–41 mm long; leaves 3–19 cm long, 2–9 cm wide, softly pubescent on the lower surface or on both surfaces; corolla lobes pubescent on outer surface"	"Parsonsia velutina"
6	"Petiole less than 5 mm long; leaves usually 4.5–10 cm long, 0.5–3 cm wide, glabrous on both surfaces; corolla lobes minutely puberulous on outer surface"	"Parsonsia lenticellata"
7	"Calyx lobes spreading and recurved in open flowers; corolla lobes hood-shaped"	8
7	"Calyx lobes appressed to corolla in open flowers; corolla lobes not hood-shaped"	9
8	"Leaves on adult plants very thin and soft, lanceolate to ovate or elliptic, 1.4–4 cm wide, margins flat; corolla lobes induplicate-valvate in bud"	"Parsonsia induplicata"
8	"Leaves on adult plants usually thick and tough, linear to lanceolate, rarely broadly lanceolate, 0.2–1.5 (–2.5) cm wide, margins recurved; corolla lobes contorted-imbricate in bud"	"Parsonsia paulforsteri"
9	"Leaves on adult plants grey to pale purplish when dry, c. 3–5 cm long; corolla lobes erect"	"Parsonsia bartlensis"
9	"Leaves on adult plants green above, green to pale brown below, 6–14 cm long; corolla lobes ascending to erect"	10
10	"Leaf apex shortly acuminate to a fine point or mucronate; leaves oblong-ovate, to 14 cm long, lower surface with coarser net veins usually distinct; corolla lobes white or yellowish"	"Parsonsia blakeana"
10	"Leaf apex long-acuminate to a fine point; leaves ovate-lanceolate to ovate-elliptic, to 12 cm long, lower surface smooth, veins obscure except for midvein and 5–8 pairs of secondary veins; corolla lobes cream or green with red tips"	"Parsonsia grayana"
11	"Corolla lobes pubescent (sometimes minutely so) or hirsute externally"	12
11	"Corolla lobes glabrous externally or with some isolated fine hairs"	25
12	"Fine vein reticulum strongly raised and prominent on upper surface of dried leaves"	13
12	"Fine net vein reticulum not raised or prominent on upper surface of dried leaves (sometimes the coarser net veins slightly raised)"	14
13	"Vines climbing by adventitious roots; leaf lamina 4-24 cm x 1.5-8 cm; corolla cream, yellowish or pink; follicles 10-20 cm long; seeds not ribbed; mainland Australia"	"Parsonsia straminea"
13	"Vines without adventitious roots; leaf lamina (4-)6-9 x (1.5-)2-3 cm; corolla usually orange; follicles 10-12 cm long; seeds ribbed; Lord Howe Island"	"Parsonsia howeana"
14	"Leaves of adult plants linear or narrowly lanceolate, 7–18 times as long as wide"	15
14	"Leaves of adult plants lanceolate to very broadly ovate, 1.2–6 times as long as wide"	16
15	"Anther cone raised high above corolla on twisted filaments; corolla lobes linear, glabrous on inner surface except at base and sometimes near apex, revolute, more than 4 times as long as tube"	"Parsonsia eucalyptophylla"
15	"Anther cone partly enclosed in corolla with filaments short, straight; corolla lobes oblong-acute, shortly hirsute over entire inner surface, spreading or recurved but not revolute, less than twice as long as tube"	"Parsonsia diaphanophleba"
16	"Anthers bearded along the median dorsal line"	"Parsonsia densivestita"
16	"Anthers glabrous"	17
17	"Corolla lobes linear, revolute, 2.5–6 times as long as tube"	18
17	"Corolla lobes ovate to narrowly lanceolate, spreading to strongly recurved or reflexed, less than 2.5 times as long as tube"	19
18	"Anther cone just fully exserted from corolla, 3.5–4 mm long; filaments straight; pedicels 3–6 mm long"	"Parsonsia sankowskyana"
18	"Anther cone raised high above corolla, c. 3 mm long; filaments spirally twisted to nearly straight; pedicels 7–9 mm long"	"Parsonsia brisbanensis"
19	"Adult leaves glabrous or finely hairy along the veins, with hairs ±colourless"	20
19	"Adult leaves with lower surface densely, softly pubescent, upper surface pubescent or scabrous, with hairs brown"	22
20	"Leaves on adult plants narrowly lanceolate to ovate-lanceolate, 3.5–6 times as long as wide, cuneate or narrowly cuneate at base; secondary veins 9–14 on either side of midvein"	"Parsonsia brownii"
20	"Leaves on adult plants ovate or broadly ovate, 1–4 times as long as wide, rounded or broadly cuneate or cordate at base; secondary veins 8 or fewer on each side of midvein"	21
21	"Leaves ovate to very broadly ovate, 1.2–1.8 times as long as wide, mucronate or shortly acuminate, 4–9 cm wide; capsule 1.3–2.6 cm diam., 9–14 cm long"	"Parsonsia largiflorens"
21	"Leaves ovate or ovate-lanceolate, 1.9–4 times as long as wide, acuminate to long-acuminate to a fine point, 1–4 (–6) cm wide; capsule very slender, 0.4–1 cm wide, 10–21 cm long"	"Parsonsia langiana"
22	"Corolla and calyx lobes shortly and densely hirsute externally; corolla lobes papillose internally; filaments with several, short, deltoid bristles"	"Parsonsia ferruginea"
22	"Corolla and calyx lobes with a tomentum of fine, slender hairs; corolla lobes not papillose internally; filaments pubescent with slender hairs"	23
23	"Small domatia distinct on leaf lower surface in axils of secondary veins; corolla lobes strongly recurved or reflexed"	"Parsonsia fulva"
23	"Domatia lacking on leaf lower surface in axils of secondary veins; corolla lobes spreading or recurved"	24
24	"Corolla tube subglobose at base, the lobes 2.7–3 mm long; capsules narrowly ellipsoidal, a little inflated near base, 1.7–2 cm diam., finely pubescent"	"Parsonsia wongabelensis"
24	"Corolla tube cylindrical or slightly inflated, not ovoid or subglobose, the lobes c. 1.8 mm long; capsules very slender, 0.4–0.8 cm diam., glabrescent"	"Parsonsia langiana"
25	"Stems and petioles exuding white milky latex when cut"	26
25	"Stems and petioles exuding clear watery latex (sometimes yellow-tinged) when cut"	28
26	"Inflorescences with 3–11 flowers; corolla lobes oblong, acute, less than twice as long as tube; corolla tube inflated, ovoid; anther tails slightly divergent"	"Parsonsia dorrigoensis"
26	"Inflorescences large, with 15–100 or more flowers; corolla lobes linear, 4–7 times as long as tube; corolla tube tapering or cylindrical, not inflated; anther tails convergent"	27
27	"Corolla lobes 5.5–8 mm long; anther cone c. 4 mm long, strongly exserted from corolla in open flowers; leaf laminas 7–14 cm long, 3.5–8 cm wide"	"Parsonsia latifolia"
27	"Corolla lobes 4–5 mm long; anther cone 2.5–3 mm long, partly exserted; leaf laminas 3.5–8 cm long, 2.5–5 cm wide"	"Parsonsia longipetiolata"
28	"Leaves with a prominent, strongly raised, fine vein reticulum on both surfaces when dry; corolla tube more than twice as long as lobes; adult plants creeping and rooting, or trailing, not twining"	"Parsonsia larcomensis"
28	"Leaves without a raised, fine vein reticulum on either surface; corolla tube less than twice as long as lobes; adult plants twining"	29
29	"Margins of leaves crisped, or occasionally flatter and finely toothed all around"	"Parsonsia lilacina"
29	"Margins of leaves not crisped, entire or with a few teeth at base only"	30
30	"Leaves with secondary veins ±obscure on lower surface, faintly visible above"	"Parsonsia rotata"
30	"Leaves with secondary veins conspicuous and usually raised below, distinctly visible above"	31
31	"Undersurface of leaves blackish purple, purple-brown or very dark brown when dried"	32
31	"Undersurface of leaves green when dry, sometimes purple-tinged, sometimes pale brown"	33
32	"Corolla lobes c. 2 mm long, pale yellow or creamy, without a thickened median strip; anther cone whitish, c. 1/3-exserted; inflorescence with (6–) 9–20 flowers."	"Parsonsia purpurascens"
32	"Corolla lobes 4–5 mm long, with a yellow or orange, thickened median strip, white margins and red base; anther cone usually red, 2/3-exserted; inflorescence with 2–9 flowers"	"Parsonsia kroombitensis"
33	"Corolla tube inflated, globose; anthers cohering lightly, often separating in pressed specimens"	"Parsonsia ventricosa"
33	"Corolla tube cylindrical, tapering to base or slightly inflated at base, not globose; anthers usually remaining coherent or connate"	34
34	"Leaf laminas softly pubescent on lower surface, the upper surface scabrous-hairy to glabrescent"	"Parsonsia tenuis"
34	"Leaf laminas glabrous on both surfaces or puberulous"	35
35	"Petioles usually 1–7 mm long; laminas deltoid or narrowly deltoid, broadest at or near base, base rounded-truncate or cordate, apex gradually acute; inflorescence with 2–7 flowers"	"Parsonsia wildensis"
35	"Petioles 7–35 mm long; laminas not deltoid, not broadest at or near base; inflorescence with more than 10 flowers"	36
36	"Leaves thick, leathery to stiff, oblong, broadly oblong or oblong-obovate, apex obtuse, rounded-acute or retuse, apiculate; corolla lobes linear, 4–6 times as long as tube"	"Parsonsia plaesiophylla"
36	"Leaves rather thin, chartaceous to firm, not oblong or broadly oblong or oblong-obovate, apex shortly acuminate or mucronate; corolla lobes less than 2.5 times as long as tube"	37
37	"Corolla lobes 2–2.5 mm long, with a thickened, papillose median strip; leaves on juvenile plants ovate or oblong-ovate, often sinuately 3-lobed, (leaves on flowering shoots also sometimes 3-lobed)"	"Parsonsia leichhardtii"
37	"Corolla lobes 3.2–6.3 mm long, without a thickened, papillose median strip; leaves on juvenile plants not sinuately lobed"	38
38	"Panicles much shorter than leaves; corolla constricted in upper part of tube; corolla lobes obtuse, 5.5–6.3 mm long; filaments spirally twisted"	"Parsonsia alboflavescens"
38	"Panicles about as long as leaves or a little longer; corolla ±funnel-shaped, not constricted; corolla lobes acute, 3–4.2 mm long; filaments not twisted"	"Parsonsia blakeana"