| 1 | Stems and sepals glabrous; petioles absent. |
| 1' | Stems and sepals puberulous to pubescent; petioles present. |
| 2 | Stems ± quadrangular, grooved; leaves oblong; stamens 5, filaments c. 1 mm long; styles 0.3 mm long. |
| 2' | Stems ± quadrangular, winged; leaves linear; stamens 10, filaments 3-4 mm long; styles 2-2.5 mm long |
| 3 | Hairs simple |
| 3' | Hairs stellate |
| 4 | Ovules many; several seeds in the capsule |
| 4' | Ovules 3; one seed in the capsule |
| 5 | Stems hirsute in two grooves; petioles 1-4 mm; stamens 5; styles 1 mm, finely puberulous; seeds spherical |
| 5' | Stems sparsely puberulous all around, glabrous in lower part; petioles 5-35 mm; stamens 10; styles 2 mm, glabrous |
