| 1 | Fertile flowers brownish or yellowish, distinct from the blue or purple sterile flowers; raceme 8-30 cm long; seeds c. 2.5 mm diam.; bulb 3-4 cm wide |
| 1' | Fertile flowers blue or violet, similar to the sterile but usually darker in colour; raceme less than 4 cm long; seeds c. 2 mm diam.; bulb 1-2 cm wide |
| 2 | Flowers appearing in autumn (Oct.-Dec.); perianth sky-blue, oblong-campanulate, scarcely constricted at mouth |
| 2' | Flowers appearing in winter or spring (Dec.-March); perianth dark blue or violet |
| 3 | Perianth-lobes white or whitish; perianth-tube dark blue, constricted at mouth; leaves 1.5-6 mm wide |
| 3' | Perianth-lobes concolorous with tube, dark indigo or violet; tube not (or indistinctly) constricted at apex; leaves 1-3 mm wide |
