| 1 | Sepals with a c. 0.5 mm broad, 3-nerved, pubescent, greenish median band not reaching the apex |
| 1' | Sepals entirely scarious or with a narrow, glabrous, purple midrib of varying length. |
| 2 | Sepals with midrib reaching 1-1.5 mm below apex; petals narrowly oblong; anthers oblong, style 1.2-2 mm |
| 2' | Sepals without midrib or midrib only visible to c. 1 mm from the base; anthers orbicular; style 0.2-0.5 mm |
| 3 | Sepals without midrib; petals minute, 0.5-1 mm long, apex not bifid. |
| 3' | Sepals with a 1 mm long midrib visible at the base; petals 1.2-2 mm long, apex often bifid |
