Further testing of this new key is required.
| 1 | Inflorescence leafy to the top, consisting entirely of axillary cymose clusters |
| 1' | Inflorescence not leafy to the top, a terminal leafless spike or panicle present |
| 2 | Perianth-segments 4 or 5; leaves with distinct membranous margin |
| 2' | Perianth-segments 3; leaves without distinct membranous margin |
| 3 | Bracteoles strongly spinous-acuminate, about twice as long as the perianth |
| 3' | Bracteoles not spinous-acuminate, subequalling or shorter than the perianth |
| 4 | Larger leaves of the main stem at least 2.5 times as long as broad; perianth-segments shortly (to c. 0.25 mm long) mucronate |
| 4' | Larger leaves of the mein stem less than 2.5 times as long as broad; perianth-segments extremely shortly (sometimes scarcely at all) mucronate |
| 5 | Capsule indehiscent, irregularly rupturing, very strongly muricate; seeds with low, scurfy verrucae with the same shape as the reticulum of the testa |
| 5' | Capsule dehiscent by a circumscissile lid, sometimes wrinkled but never strongly muricate; seeds without low papillae |
| 6 | Axils of stem leaves usually with a pair of spines; female flowers only at the base of each inflorescence branch |
| 6' | Axils of stem leaves without spines; female flowers evenly distributed |
| 7 | Female perianth-segments spathulate to narrowly oblong-spathulate, obtuse or emarginate |
| 7' | Female perianth-segments lanceolate to oblong, acute to acuminate |
| 8 | Plant dioecious, having male or female flowers only; terminal part (20-30 cm long) and branches of inflorescence very long and narrow, branches spreading to patent, in ripe stage often pendent |
| 8' | Plant monoecious, having male and female flowers; terminal part (2-14 cm long) and branches of inflorescence short and thick, branches erect or basal branches spreading to patent, or even terminal inflorescence arching or pendulous |
| 9 | Terminal inflorescence pendent from the base, often purplish-red; perianth-segments overlapping laterally, obovate to rhombic, slightly shorter than fruit |
| 9' | Terminal inflorescence erect, not conspicuously purplish-red; perianth-segments not overlapping, more or less strap-shaped or spathulate, longer than fruit |
| 10 | Stem at the base of the inflorescence densely hairy; inflorescence with erect branches; bracteoles c. twice as long as perianth |
| 10' | Stem at the base of the inflorescence glabrous or sparsely hairy; inflorescence at the base often with spreading branches; bracteoles c. 1.2-1.5 times as long as perianth |
| 11 | Ripe utricle with a distinct inflated “beak”; inner perianth-segments of female flowers commonly acute; longer bracteoles of the female flowers mostly c. twice as long as the perianth |
| 11' | Ripe utricle with a smooth, narrow “beak”; inner perianth-segments of female flowers commonly obtuse; longer bracteoles of the female flowers 1-1.5 times as long as the perianth |
