Flowers in racemes, usually many-flowered. Sepals equal or nearly so. Petals white or pink. Stamens usually 6, rarely 4.
Siliqua linear, c. 1 wide, erect, dehiscent, the valves released suddenly from the base upwards, ejecting the seeds; valves flat, without conspicuous veins; septum margin flanged.
Note: species numbered 6–9 are included by Hewson (1982) as informal variants of the C. lilacina complex. Further investigation is required to decide on appropriate rank for these taxa.
| | Key to the species | |
| 1 | Vegetative parts with hairs (look closely at margins of cauline leaves and pedicels) | 2 |
| Vegetative parts glabrous (sometimes hairy in C. paucijuga, rarely hairy in C. lilacina) | 6 |
| 2 | Most flowers with 4 stamens; plant sparsely hirsute | Cardamine hirsuta |
| Most flowers with 6 stamens; plants hairy overall, or plant with hairs on cauline leaves and/or pedicels
Back to 1 | 3 |
| 3 | Plants glabrous except for hairs on margins of cauline leaves and/or pedicels | 4 |
| Plant mostly hairy
Back to 2 | 5 |
| 4 | Plants minutely papillose on pedicels and sometimes along margins of cauline leaves; terminal pinna of cauline leaves entire | Cardamine papillata |
| Plants with ciliate margins on cauline leaves; terminal pinna of cauline leaves 5–9-lobed
Back to 3 | Cardamine microthrix |
| 5 | Upper surface of leaves with hairs (hairs erect in fresh material); seeds 1–1.2 mm long; base of stem green and moderately hairy | Cardamine flexuosa |
| Upper surface of leaves mostly glabrous; seeds 0.8–1.0 mm long; base of stem either purple and pubescent, or green and moderately hairy
Back to 3 | Cardamine occulta |
| 6 | Plants semiaquatic, of swampy habitat; leaves filiform; stems weak, to 1 m long with numerous fine roots at nodes | Cardamine tenuifolia |
| Plants generally terrestrial; leaves not filiform; stems nodes without numerous fine roots
Back to 1 | 7 |
| 7 | Vegetative stems stoloniferous; basal leaves usually simple, ovate, arising singly at intervals along the horizontal stem, not forming a basal rosette | Cardamine astoniae |
| Stems not stoloniferous; basal leaves forming a rosette (sometimes not evident in Cardamine moirensis)
Back to 6 | 8 |
| 8 | Plants spreading by means of robust, white, underground stems, which ascend to form new rosettes; plant forming dense swards up to 1 m diam., confined to alpine regions of Kosciuszko N.P | Cardamine robusta |
| Plants not as above
Back to 7 | 9 |
| 9 | Terminal pinna of basal leaves 2- or 3-lobed | 10 |
| Terminal pinna of basal leaves entire
Back to 8 | 11 |
| 10 | Terminal pinna of basal leaves cordate at base; flowers 3–6 mm long | Cardamine paucijuga |
| Terminal pinna truncate-cuneate; flowers 2–3.5 mm long
Back to 9 | Cardamine moirensis |
| 11 | Seeds 1.5–3 mm long | Cardamine lilacina |
| Seeds <1.5 mm long
Back to 9 | 12 |
| 12 | Basal leaves either, entire and spathulate, or pinnate with terminal pinna elliptic | Cardamine franklinensis |
| Basal leaves long petiolate, pinnate, with terminal pinna with a cordate base
Back to 11 | Cardamine paucijuga |
