1 | Leaves 3-lobed |
1' | Leaves not lobed |
2 | Pseudostipules lacking; lateral lobes of leaves perpendicular to middle lobe; superior lobe of perianth triangular and emarginate at apex |
2' | Pseudostipules present; lateral lobes of leaves falciform, pointing partly forward; superior lobe of perianth ovate, with a long apical filament at least 10 cm long |
3 | Leaves peltate |
3' | Leaves not peltate, or very slightly so |
4 | Plant cauliflorous and leaves wider than long |
4' | Plant not cauliflorous or, if cauliflorous, then leaves longer than wide |
5 | Limb of perianth not spreading, but at first reflexed backwards to the utricle and apically coming forward, but finally recurved outwards and forming a horse-shoe-shaped cavity around the mouth of the tube; fruit more than 6 cm long, external wall thick, woody |
5' | Limb of perianth spreading; fruit similar or thin-walled |
6 | Upper part of the limb wider than long, apex rounded; fruit more than 6 cm long, external wall thick, woody |
6' | Upper part of the limb longer than wide, apex acute; fruit up to 6 cm long, external wall thin, chartaceous |
7 | Perianth with only 1 superior lobe (with small inferior lobe in A. cremersii). |
7' | Perianth with 2 lobes (2 lateral lobes, or 1 superior and 1 inferior lobe). |
8 | Perianth lobe hangmg, like a scallopped tape |
8' | Perianth lobe erect |
9 | Inflorescences cauliflorous or axillary racemes |
9' | Flowers solitary or arranged in axillary inflorescences |
10 | Flowers solitary; inside wall of dehiscing fruit not comb-like |
10' | Flowers in axillary inflorescences; inside wall of dehiscing fruit comb-like. |
11 | Perianth large, utricle 3 x 1.5 cm, larger than the lobe |
11' | Perianth with the utricle smaller than the lobe |
12 | Perianth lobe triangular, without fimbriae, but with dark violet spots |
12' | Perianth lobe with fleshy, dark purple fimbriae |
13 | Perianth lobe triangular, acute, marginally reflexed |
13' | Perianth lobe distally ovoid, with acuminate apex |
14 | Perianth lobe with terminal filiform appendage; seed wings apically truncate, seed base truncate |
14' | Perianth lobe triangular with acute apex; seed wings apically rounded, seed base cordate |
15 | Perianth with 2 lateral lobes |
15' | Perianth with superior and inferior lobe |
16 | Utricle less than 1.5 cm long, superior lobe linear, twisted |
16' | Utricle more than 2 cm long |
17 | Superior lobe deeply 2-fid, up to 5 cm long |
17' | Superior lobe paddle-shaped, 1.5-3 cm long, wider in its distal part |