| 1 | Flowers mostly 3 (rarely 2 or 4) in a verticillaster, radially spreading |
| 1' | Flowers generally 2 in a verticillaster, secund. |
| 2 | Flowering calyx 1-1.5 mm long; pedicels ± perpendicular to the rachis. Leaves broadly ovate, rounded or reniform, the base often cordate |
| 2' | Flowering calyx 3-4 mm long; pedicels always obliquely erect (at angles of 60° to 75°) to the rachis. Leaves lanceolate or narrowly ovate, the base acute to rounded |
