Flowers either bisexual or unisexual, arranged in terminal leafy cymes. Calyx tubular, 5-toothed, 10–30-veined, sometimes appearing inflated. Petals present or absent, when present clawed, usually with two erect appendages at summit of claw. Stamens 10. Ovary either 3–5-locular at base and 1-locular above or 1-locular throughout; styles 3–5.
Capsule borne on a gynophore and usually enclosed within the calyx; opening by twice as many teeth as styles; seeds numerous, reniform. Most are weeds of disturbed ground.
The systematics of this group of plants is not yet satisfactorily understood. In some parts of the world, the segregate genera Lychnis, Melandrium, etc., are recognised; in others Silene is used in the broad sense to include those genera. Here we are following the Australian Plant Census in using Silene in the broad sense, but that could change with further study.
| | Key to the species | |
| 1 | Styles 5 (occasionally 4 in a few flowers in an inflorescence); capsule with 5 or 10 teeth (rarely 4 or 8) | 2 |
| Styles 3 (occasionally 4 in a few flowers in an inflorescence); capsule with 3 or 6 teeth (rarely with 4, 5, 8 or 10) | 5 |
| 2 | Inflorescence a condensed cyme; flowers sessile or nearly so; [petals scarlet, or rarely pink or white] | Silene chalcedonica |
| Inflorescence a sparse, elongated cyme; flowers with pedicel usually longer than the calyx
Back to 1 | 3 |
| 3 | Leaf blades with dense silky grey-white tomentose indumentum; flowers bisexual; petals scarcely divided at apex, [rich magenta-pink, rarely white; mature calyx 15–20 mm long] | Silene coronaria |
| Leaf blades sparsely to densely hirsute or pubescent; flowers unisexual; petals distincly split at apex (usually for at least half the length of the visible limb)
Back to 2 | 4 |
| 4 | Petals white; flowers opening in evenings, fragrant; mature calyx 17–25 mm long, with teeth 5–11 mm long in female flowers; capsule with 10 erect to spreading teeth; upper surface of leaves ± glandular; plants dioecious | Silene latifolia |
| Petals bright pink to red; flowers opening in daytime, not fragrant; mature calyx 10–15 mm long, with teeth 2.5–3.5 mm long in female flowers; capsule with 10 strongly recurved teeth; upper surface of leaves not glandular; plants monoecious
Back to 3 | Silene dioica |
| 5 | Calyx glabrous or nearly so, with 20 or 30 longitudinal veins and obvious cross-veins, balloon-like (strongly inflated) in fruiting stage | 6 |
| Calyx hairy with simple, multicellular or glandular hairs, with 10 longitudinal veins, occasionally with fainter cross-veins (S. nocturna), sometimes somewhat inflated but never balloon-like
Back to 1 | 7 |
| 6 | Plant erect, 24–80 cm high; flowers numerous in (usually elongated) cymes, bracts scarious; capsule teeth erect to spreading | Silene vulgaris |
| Plant decumbent, 10–40 cm high; flowers solitary or few, bracts herbaceous; capsule teeth recurved
Back to 5 | Silene uniflora |
| 7 | Calyx with short glandular and (usually long) multicellular hairs; petals white, occasionally with a pinkish tinge | 8 |
| Calyx with non-glandular hairs; hairs multicellular, simple or both; [mature calyx 7–14 mm long]; petals pink
Back to 5 | 9 |
| 8 | Fruiting calyx 15–24(-40) mm long, cylindrical, contracted at base around capsule | Silene noctiflora |
| Fruiting calyx 7–10 mm long, ovoid, not contracted at base around capsule
Back to 7 | Silene gallica |
| 9 | Calyx nerves visible but not thickened; petals obvious and deeply divided; fruiting calyx and enclosed capsule cylindrical; capsule with 3 teeth | Silene nocturna |
| Calyx nerves obvious, strongly thickened; petals inconspicuous or absent, not deeply divided; fruiting calyx and enclosed capsule not cylindrical; capsule with 6 teeth
Back to 7 | 10 |
| 10 | Fruiting calyx and enclosed capsule obconical to campanulate; calyx 6–8(rarely 10) mm long; inflorescence bracts shorter than flowers | Silene apetala |
| Fruiting calyx and enclosed capsule ovoid to globose; calyx 10–13 (rarely 15) mm long; inflorescence bracts longer than flowers (to twice as long)
Back to 9 | Silene tridentata |
