1 | Saprophytic plants without chlorophyll (mycoheterotrophic); leaves scale-like, yellow, white, pink, or purple |
1' | Plants with chlorophyll; leaves not scale-like, green |
2 | Calyx lobes connate into a tubular calyx; corolla far exceeding calyx, long-persistent; plants variously coloured |
2' | Calyx with almost free lobes; corolla barely exceeding calyx, soon falling off; plants completely white |
3 | Flowers/fruits axillary |
3' | Flowers/fruits terminal |
4 | Plants woody, shrubs or small trees, sometimes perennial herbs; leaves large, 6.5-35 cm long, 3-11-veined |
4' | Plants herbaceous, herbs, sometimes slightly woody at base; leaves small, 0.5-8 cm long; 1-3-veined |
5 | Leaves lanceolate, > 1.5 cm long; flowers in clusters of 2-8 in each of the upper leaf axils, no terminal flower; perennial herb |
5' | Leaves linear, < 1 cm long; flowers 1-2 in upper leaf axils, with terminal flower; annual herb |
6 | Fruit a berry; corolla lobes 8-12 |
6' | Fruit a capsule; corolla lobes 4-5 (rarely 6) |
7 | Calyx lobes free, decussate; corolla 6-merous |
7' | Calyx lobes fused at base into a campanulate or tubular calyx, imbricate; corolla 4-5-merous |
8 | Calyx coriaceous, with a thickened, glandular dorsal area on each lobe, calyx lobes obtuse (except Symbolanthus with acute lobes, but lobes then at least 30 mm long) |
8' | Calyx herbaceous to membranaceous, often with thin, dorsal keels but not with a thick glandular area on each lobe; calyx lobes acute to acuminate |
9 | Perennial plants; shrubs or small trees, all stems woody |
9' | Annuals or short-lived plants; herbs, sometimes woody at base |
10 | Corolla red to pink or blue to purple; calyx divided more than 2/5 of its length |
10' | Corolla yellow to light green; calyx divided at most 1/3 of its length |
11 | Corolla blue to purple; calyx divided 2/5-3/5 of its length, calyx lobes circular; capsule woody |
11' | Corolla red to pink; calyx divided 9/10 of its length, calyx lobes lanceolate to elliptic; capsule leathery, often glossy, nearly berry-like |
12 | Leaves petiolate, veins visible below; bracts leaf-like; inflorescence with more than 6 flowers; pollen in monads |
12' | Leaves subsessile, veins not visible below; bracts scale-like; inflorescence with up to 6 flowers; pollen in tetrads |
13 | Corolla tubes less than 2 times as long as corolla lobes (except I. tatei, with pink corollas); pollen in spinose polyads |
13' | Corolla tubes more than 2 times as long as corolla lobes; pollen in tetrads (polyads in C. purpurascens) |
14 | Flowers nodding |
14' | Flowers erect to horizontal |
15 | Leaves sessile; corolla 33-50 mm long, red to pink; capsule 11-13 mm long |
15' | Leaves petiolate; corolla 3-6 mm long, white or green; capsule 2-5 mm long |
16 | Inflorescence a raceme or congested spike with 2-4 flowers in each whorl; flowers sessile or shortly pedicellate; stamens exerted from corolla mouth |
16' | Inflorescence a lax to congested cyme; flowers pedicellate; stamens included in corolla |
17 | Inflorescence with at least some monochasially branching branches |
17' | Inflorescence strictly dichasially branching |
18 | Leaf blades up to 0.3 cm wide; stigma capitate; pollen in monads |
18' | Leaf blades over 0.3 cm wide; stigma bilamellate; pollen in tetrads |