1Leaves in whorls of 3 or more
1'Leaves opposite
2Leaves densely pubescent all over beneath
2'Leaves glabrous or only pubescent on midrib and secondary veins beneath
3Corolla tube ≥ 10 mm long
3'Corolla tube < 8 mm long
4Corolla tube pubescent in throat
4'Corolla tube glabrous in throat
5Corolla campanulate
5'Corolla subcylindrical, salverform, rotate or urceolate
6Hairs on corolla tube dense rufous brown
6'Hairs on corolla tube very short and cream coloured or pale fawn, or corolla tube glabrous outside
7Tips of corolla lobes glabrous outside; flowers densely clustered at inflorescence ends
7'Tips of corolla lobes pubescent outside; flowers laxly arranged or clustered
8Corolla tube ≥ 5.4 mm long. — Not in New Guinea
8'Corolla tube < 6 mm long. — Those > 3 mm long only in New Guinea
9Corolla tube somewhat inflated, wider than head in bud; anthers with large boss on the back
9'Corolla tube not inflated, narrower or same width as head in bud; no large boss on anthers
10Hairs on inflorescence spreading
10'Hairs on inflorescence appressed
11Leaf base cuneate to obtuse
11'Leaf base cordate
12Inflorescence 14-20 cm long; mature corolla tube c. 2 mm wide
12'Inflorescence 3.5-13 cm long; mature corolla tube 3-4 mm wide
13Corolla tube glabrous outside, lobes 3.9-5.6 times as long as tube, strongly reflexed when mature. — Lesser Sunda Islands
13'Corolla tube puberulent or glabrous outside, lobes 0.7-2.2 times as long as tube, erect or spreading when mature. — Widespread
14Stamens subsessile or with very short filaments. — New Guinea
14'Stamens with well-developed filaments. — Widespread
15Leaves without prominent venation; disk lobes free
15'Leaves with prominent venation above; disk lobes fused
16Corolla pinkish or reddish, with a rounded or apiculate head in bud; fruit spiny
16'Corolla yellow, with an acuminate head in bud; fruit smooth
17Filaments twisted around the style
17'Filaments straight or, if bent, not twisted around the style
18Flowers hour-glass-shaped; corolla tube > 7 mm long
18'Flowers not hour-glass-shaped; corolla tube < 6 mm long
19Flowers fleshy, corolla lobes strongly overlapping in bud; sepal lobes rounded to obtuse
19'Flowers not fleshy, corolla lobes only slightly overlapping or appearing valvate in bud; sepals acuminate to obtuse
20Anthers exserted completely beyond mouth of corolla tube; lobes 2.4-5.6 times as long as tube
20'Anthers partially included in corolla tube or located at mouth of corolla tube; lobes 0.4-3.1 times as long as corolla tube
21Inflorescence delicate, with flowers clustered at inflorescence branch ends forming rounded heads; fruits fusiform, ≤ 12 cm long. — Lesser Sunda Islands
21'Inflorescence more robust, flowers not forming rounded heads; fruits linear, ≥ 15 cm long. — Moluccas, New Guinea
22Filaments with large projections on the sides; dried leaves usually somewhat glaucous beneath
22'Filaments without large projections on the sides; dried leaves not glaucous
23Corolla bearded in throat with brown hairs, usually densely brown pubescent outside, rarely glabrous
23'Corolla glabrous or pale-coloured pubescent in throat and glabrous, brown papillose or shortly puberulent outside
24Sepals erect or only slightly spreading at apex; corolla tube 4.2-5.4 mm long
24'Sepals strongly reflexed; corolla tube 1.9-4.5 mm long
25Leaf base cuneate, rarely to obtuse; leaves 1.8-4.8 times as long as wide
25'Leaf base cordate to rounded; leaves 1.1-2 times as long as wide
26Inflorescence 2.7-6.7 cm long; corolla tube 1.9-2.2 mm long. — Java to Flores
26'Inflorescence 7-18.5 cm long; corolla tube 2.9-3.2 mm long. — Bismarck Archipelago
27Corolla with downward pointing hairs in throat
27'Corolla glabrous or with upward pointing hairs in throat
28Open corolla campanulate or subcampanulate
28'Open corolla salverform or with narrow tube and erect lobes
29Tertiary venation densely reticulate
29'Tertiary venation largely obscure, occasionally slightly prominent
30Corolla lobes 1.8-3.1 times as long as tube
30'Corolla lobes 0.7-1.3 times as long as tube
31Inflorescence pubescent all over; corolla tube 1.3-2 mm long; leaves 1-5.1 cm long
31'Inflorescence pubescent only in upper parts; corolla tube 2-3.4 mm long; leaves 2.1-10.8 cm long
32Corolla tube much narrower than corolla bud head
32'Corolla tube wider than to more or less same width as corolla bud head
33Tertiary venation densely reticulate; leaves usually drying dull ochre above
33'Tertiary venation obscure or only laxly reticulate; leaves not drying dull ochre above
34Buds ovoid in shape; often papillose outside; disk entire
34'Buds cylindrical or club-shaped; not papillose outside; disk usually of 5 separate lobes
35Inflorescence 3-21 cm long, flowers not forming a dense rounded cluster at ends
35'Inflorescence 1.1-4 cm long, flowers forming a dense rounded cluster at ends