1 | Inflorescence a pedunculate umbel of 2 or more triads |
1' | Inflorescence other than a pedunculate umbel of triads (e.g., a head, simple umbel, solitary flower or sessile cluster) |
2 | Triads with all flowers closely sessile |
2' | Triads with at least the lateral flowers pedicellate, sometimes very shortly so.. |
3 | Rays in the umbel 2-4; corolla 14-18 mm long; anther equal to the free part of the filament; leaf lamina flat |
3' | Rays in the umbel 5 or more; corolla 18-20 mm long; anther much shorter than the free part of the filament; leaf lamina often folded . |
4 | Rays in the umbel 2-5 |
4' | Rays in the umbel 6 or more |
5 | Rays in the umbel mostly 4 or 5; central flowers of the triads mostly pedicellate.. |
5' | Rays in the umbel mostly 2 or 3; central flowers of the triads sessile |
6 | Corolla in mature bud ridged or winged longitudinally, lacking a globular inflation at the base; anthers not transversely septate |
6' | Corolla in mature bud terete or angular but not ridged or winged longitudinally, with a globular inflation at the base; anthers transversely septate... . |
7 | Corolla 5- or 6-merous; triads with the central flower sessile; leaves opposite... . |
7' | Corolla 4-merous; triads with all flowers shortly pedicellate; leaves rarely opposite, mostly in whorls of 3-6 (rarely scattered) |
8 | Rays of the umbel 6-8; peduncle less than 10 mm long.. . |
8' | Rays of the umbel 9 or more; peduncle more than 10 mm long |
9 | Leaves opposite, ternate or scattered ternate; lamina up to 10 cm long |
9' | Leaves in whorls of 3-6; lamina 10-30 cm long |
10 | Inflorescence a pedunculate or sessile 6- or 9-flowered head formed from 2 or 3 sessile triads |
10' | Inflorescence not as above (a pedunculate or sessile simple umbel or a solitary flower) |
11 | Leaves ternate; inflorescence 9-flowered |
11' | Leaves opposite; inflorescence 6-flowered |
12 | Leaves sessile |
12' | Leaves obscurely or distinctly petiolate |
13 | Leaves truncate to cordate at the base; peduncle rudimentary (inflorescence sessile) |
13' | Leaves cuneate to truncate at the base; peduncle 2-5.5 mm long. |
14 | Leaves glossy grey/green above and dull brown below; petiole distinct, 5-10 mm long; inflorescence peduncle 0.5-2.5 mm long |
14' | Leaves dull on both sides at least when dry; petiole short or obscure, mostly less than 5 mm long; inflorescence peduncle usually 2-11 mm long |
15 | Peduncle 5-11 mm long; leaf lamina obtuse or rounded at the apex |
15' | Peduncle usually 2-4 mm long; leaf lamina acute at the apex |
16 | Inflorescence a sessile 1- to 3-flowered umbel ( I.c., the flowers sometimes seemingly solitary) |
16' | Inflorescence a pedunculate simple umbel |
17 | Rays of the umbel c. 12; corolla 5- or 6-merous |
17' | Rays of the umbel 3-6; corolla mostly 4-merous |