| 1 | Leaves pinnate or pinnatisect |
| 1' | Leaves simple (not divided), entire, lobed or trilobed with a large terminal leaflet and 1 pair of small basal lobules |
| 2 | Calyx 5-8 mm long, densely covered with long white eglandular hairs; leaf-lobes more or less linear |
| 2' | Calyx 8-14 mm long, more or less densely covered with long glandular hairs; leaf-lobes oblong to ovate |
| 3 | Annuals; with or without a coma of coloured sterile bracts topping inflorescence; fruiting calyces strongly deflexed |
| 3' | Perennials or biennials; without a coma; fruiting calyces not or somewhat deflexed |
| 4 | Leaf-margins subentire to finely crenulate; leaves simple or some trilobed, rugulose; upper lip of corolla more or less straight |
| 4' | Leaf-margins irregularly crenulate, erose or lobed; leaves all simple, rugose to more or less flat; upper lip of corolla more or less falcate |
| 5 | Shrub; calyx 6-10 mm long; corolla lavender, pink or white |
| 5' | Suffruticose herb; calyx 10-14 mm long; corolla white or tinged mauve |
| 6 | Leaves white-lanate/pannose, at least when young |
| 6' | Leaves green with a pilose to villous indumentum |
| 7 | Inflorescence widely candelabriform; leaves ovate to oblong; flowers white |
| 7' | Inflorescence not candelabriform; leaves very broadly ovate to suborbicular; flowers lilac |
| 8 | Leaves crenate, serrate, erose or lobed; corolla c. 12 mm long |
| 8' | Leaves irregularly crenulate or serrulate or sub-erose; corolla 15-30 mm long |
| 9 | Corolla white to cream; calyx with a dense indumentum of long white eglandular hairs |
| 9' | Corolla dark pink, purple, lilac or pale blue; calyx with a glandular indumentum |
| 10 | Corolla dark pink to deep rosy purple; bracts much shorter than corolla |
| 10' | Corolla lilac or pale blue; bracts exceeding corolla |
