| 1 | Perianth white with greenish or purplish veins; flowers slightly nodding |
| 1' | Perianth yellow, stained or striped green externally; flowers more or less erect |
| 2 | Perianth-segments sharply acuminate; bulb-tunic of interwoven fibres, often produced apically into a long collar |
| 2' | Perianth-segments blunt or subacute |
| 3 | Cauline leaves filiform, very similar to basal, usually less than 1 mm wide; pedicels usually glabrous, at least at apex; bulb-tunic fibrous |
| 3' | Cauline leaves much dilated towards base, distinct from basal leaves, 2-8 mm wide; bulb-tunic reticulate-foveolate |
| 4 | Cauline leaves subopposite at apex of naked stem; flowers usually numerous, rather crowded; pedicels villose-lanuginose; seeds c. 2.2 x 1.5 mm |
| 4' | Cauline leaves generally alternate, spaced, the lower often attached near middle of stem; seeds c. 1-1.3 mm diam. |
| 5 | Flowers 1-3(-7); perianth-segments 10-16 mm long; pedicels erect, rather stout, white-lanuginose, especially towards apex |
| 5' | Flowers (2-)3-15(-25); perianth-segments 8(-12) mm long; pedicels slender, glabrous or thinly villose, often bearded at apex |
