Annuals, biennials, or perennials; (perennials usually rhizomatous, sometimes tuberiform, stolons present in C. flagellifera, caudex present in C. bellidifolia); not scapose (subscapose in C. bellidifolia); glabrous or pubescent. Stems erect, ascending, decumbent, or prostrate, unbranched or branched. Leaves: cauline, rhizomal, or basal; rhizomal and basal rosulate or not, petiolate, blade margins entire, toothed, or 1–3-pinnatisect, or palmately lobed, sometimes trifoliolate, pinnately, palmately, or bipinnately compound (leaflets petiolulate, subsessile, or sessile); cauline (usually alternate, rarely opposite or whorled) petiolate or sessile, blade (base cuneate, attenuate, or auriculate to sagittate), margins entire, dentate, or variously lobed, (leaflets petiolulate or sessile). Racemes (corymbose or paniculate, bracteate in C. pattersonii), elongated in fruit. Fruiting pedicels erect, ascending, divaricate, or reflexed, slender or stout. Flowers: sepals (caducous), usually erect, rarely spreading or ascending, ovate or oblong, lateral pair saccate or not basally, (usually glabrous, rarely pubescent); petals (rarely absent), white, pink, purple, or lilac, obovate, spatulate, or oblanceolate, claw absent or strongly differentiated from blade, (apex obtuse, rounded, emarginate, or subemarginate); stamens (6, rarely 4), equal in length; filaments not dilated basally; anthers ovate, oblong, or linear, (apex obtuse), glabrous [rarely pubescent]; nectar glands confluent, lateral glands annular or semiannular, subtending bases of stamens, median glands present (2, rarely 4) or absent. Fruits siliques, sessile, usually linear, rarely narrowly oblong or narrowly lanceolate, smooth or torulose, latiseptate; valves (papery, elastically dehiscent, becoming spirally or circinately coiled) each not veined, glabrous or, rarely, pubescent; replum strongly flattened; septum complete, (membranous); ovules 4–80 per ovary; style usually distinct, rarely obsolete; stigma capitate. Seeds uniseriate, flattened, usually not winged, rarely margined or winged, oblong, ovoid, or globose; seed coat (smooth, minutely reticulate, colliculate, or rugose) mucilaginous or not when wetted; cotyledons accumbent, rarely incumbent. x = 7, 8.

Distribution

Nearly worldwide.

Discussion

Species ca. 200 (39 in the flora).

R. C. Rollins (1993) recognized 50 species and 18 varieties of Cardamine in North America minus Greenland. Of these, 14 species are restricted to Central America and one, C. ×incisa (Eames) K. Schumann, is not recognized here. The oversplitting of some species into poorly delimited varieties is avoided in this account, and four species (C. blaisdellii, C. holmgrenii, C. nymanii, C. umbellata) are added to the flora. Cardamine corymbosa Hooker f., a native of New Zealand, apparently is becoming naturalized in greenhouses and in some gardens in British Columbia, as evidenced from Lomer 4368 (MO), a specimen collected in Sechelt Peninsula on 6 June 2002.

Selected References

Detling, L. E. 1936. The genus Dentaria in the Pacific states. Amer. J. Bot. 23: 570–576.

Detling, L. E. 1937. The Pacific coast species of Cardamine. Amer. J. Bot. 24: 70–76.

Franzke, A. et al. 1998. Molecular systematics of Cardamine and allied genera (Brassicaceae): ITS and non-coding chloroplast DNA. Folia Geobot. 33: 225–240.

Franzke, A. and H. Hurka. 2000. Molecular systematics and biogeography of the Cardamine pratensis complex (Brassicaceae). Pl. Syst. Evol. 224: 213–234.

Harriman, N. A. 1965. The Genus Dentaria L. (Cruciferae) in Eastern North America. Ph.D. dissertation. Vanderbilt University.

Hart, T. W. and W. H. Eshbaugh. 1976. The biosystematics of Cardamine bulbosa (Muhl.) B.S.P. and C. douglasii Britt. Rhodora 78: 329–419.

Lihová, J. and K. Marhold. 2006. Phylogenetic and diversity patterns in Cardamine (Brassicaceae)—A genus with conspicuous polyploid and reticulate evolution. In: A. K. Sharma and A. Sharma, eds. 2003+. Plant Genome: Biodiversity and Evolution. 2+ vols. in parts. Enfield, N.H. Vol. 1, part C, pp. 149–186.

Lövkvist, B. 1956. The Cardamine pratensis complex—Outlines of its cytogenetics and taxonomy. Symb. Bot. Upsal. 14(2): 1–131.

Marhold, H. Kudoh, and M. Koch. 2006. Worldwide phylogeny and biogeography of Cardamine flexuosa (Brassicaceae) and its relatives. Amer. J. Bot. 93: 1206–1221.

Montgomery, F. H. 1955. Preliminary studies in the genus Dentaria in eastern North America. Rhodora 57: 161–173.

Schulz, O. E. 1903. Monographie der Gattung Cardamine. Bot. Jahrb. Syst. 32: 280–623.

Sweeney, P. W. and R. A. Price. 2000. Polyphyly of the genus Dentaria (Brassicaceae): Evidence from trnL intron and ndhF sequence data. Syst. Bot. 25: 468–478.

Lower Taxa

Cardamine angulata, Cardamine angustata, Cardamine bellidifolia, Cardamine blaisdellii, Cardamine breweri, Cardamine bulbosa, Cardamine californica, Cardamine clematitis, Cardamine concatenata, Cardamine constancei, Cardamine cordifolia, Cardamine digitata, Cardamine diphylla, Cardamine dissecta, Cardamine douglassii, Cardamine flagellifera, Cardamine flexuosa, Cardamine hirsuta, Cardamine holmgrenii, Cardamine impatiens, Cardamine longii, Cardamine macrocarpa, Cardamine maxima, Cardamine micranthera, Cardamine microphylla, Cardamine nuttallii, Cardamine nymanii, Cardamine occidentalis, Cardamine oligosperma, Cardamine pachystigma, Cardamine parviflora, Cardamine pattersonii, Cardamine penduliflora, Cardamine pensylvanica, Cardamine pratensis, Cardamine purpurea, Cardamine rotundifolia, Cardamine rupicola, Cardamine umbellata

Key

1	Racemes bracteate.	Cardamine pattersonii
1	Racemes ebracteate	> 2
2	Cauline leaves (at least some) simple (rarely absent)	> 3
2	Cauline leaves pinnately or palmately compound, 3-25-foliolate, sometimes pinnatisect and appearing compound	> 14
3	Petioles of cauline leaves auriculate basally.	Cardamine clematitis
3	Petioles of cauline leaves not auriculate basally (rarely these leaves absent)	> 4
4	Plants with distinct caudices; rhizomes absent; cauline leaves 0 or 1 (or 2).	Cardamine bellidifolia
4	Plants without caudices; rhizomes present; cauline leaves 2-23 (sometimes 1 in C. purpurea)	> 5
5	Petals 0-0.7 mm; fruiting pedicels 0.5-2(-4) mm.	Cardamine longii
5	Petals 3.5-28 mm; fruiting pedicels (5-)7-50 mm	> 6
6	Ovules 40-80 per ovary.	Cardamine rotundifolia
6	Ovules 10-24 per ovary	> 7
7	Fruits 0.8-1.6 cm × 0.8-1 mm; anthers ovate, ca. 0.2 mm; petals 3.5-5 × 1.2-1.8 mm.	Cardamine micranthera
7	Fruits (1.5-)2-6 cm × 1.2-4 mm; anthers oblong to linear, 0.6-3 mm; petals (5-)7-28 × 3-7 mm	> 8
8	Rhizomes (not fleshy), 1-3 mm diam.; rhizomal leaves usually absent	> 9
8	Rhizomes (fleshy), (3-)4-18 mm diam.; rhizomal leaves present	> 11
9	Petals 15-28 mm; sepals 6-8 mm.	Cardamine constancei
9	Petals 5-12 mm; sepals 2-4.5 mm	> 10
10	Cauline leaves (3-)5-17(-23); petals white, 7-12 mm; fruits (2-)2.5-3.7(-4) cm; stems 2-7(-10.2) dm.	Cardamine cordifolia
10	Cauline leaves 1-3; petals usually purple to pink, rarely white, 5-7(-9) mm; fruits 1.5-2.5 cm; stems to 1.5 dm.	Cardamine purpurea
11	Petals 3-5 mm wide; fruits 1.4-2 mm wide; e, c North America	> 12
11	Petals 4-8 mm wide; fruits 2-4 mm; California	> 13
12	Petals usually white, rarely pale pink; stem distally glabrous or trichomes 0.02-0.1 mm.	Cardamine bulbosa
12	Petals usually purple or pink, rarely white; stem distally with trichomes (0.2-)0.3-0.6(-0.8) mm.	Cardamine douglassii
13	Petals white or pale rose, rarely purple, 8-13(-17) mm; ovules 12-22 per ovary; stems (2-)2.7-6(-7) dm; rhizomal leaves usually 3(-7)-foliolate, rarely simple.	Cardamine californica
13	Petals usually purple or pink, rarely white, 14-18 mm; ovules 10-14 per ovary; stems 1-3 dm; rhizomal leaves simple.	Cardamine pachystigma
14	Petiole of cauline leaves basally auriculate	> 15
14	Petiole of cauline leaves not basally auriculate	> 16
15	Cauline leaves 3-foliolate; perennials (rhizomatous).	Cardamine clematitis
15	Cauline leaves (9-)13-25-foliolate; annuals or biennials.	Cardamine impatiens
16	Annuals or biennials, not rhizomatous	> 17
16	Perennials, rhizomatous	> 22
17	Rachises strongly flexuous to geniculate; petals 6-8 mm; fruits (2.5-)3-4.6 × 1.7-2.1 mm.	Cardamine macrocarpa
17	Rachises not flexuous (slightly so in C. flexuosa); petals 1.5-4(-5) mm; fruits (0.5-) 1-2.5(-3.2) × 0.6-1.5 mm	> 18
18	Basal leaves rosulate, persistent to anthesis	> 19
18	Basal leaves not rosulate, often withered by anthesis	> 20
19	Stamens usually 4, rarely 5 or 6; fruiting pedicels erect to ascending; fruitsoften appressed to rachis, valves glabrous; seeds narrowly margined.	Cardamine hirsuta
19	Stamens 6; fruiting pedicels divaricate-ascending; fruits often not appressed to rachis, valves sparsely pubescent or glabrous; seeds often not margined (wingless).	Cardamine oligosperma
20	Lateral leaflets of cauline leaves narrowly oblong, linear or filiform, 1-3 mm wide; fruits 0.6-0.9 mm wide.	Cardamine parviflora
20	Lateral leaflets of cauline leaves orbicular, ovate, elliptic, or oblong, 4-25 mm wide; fruits 0.8-1.5 mm wide	> 21
21	Rachises slightly flexuous; ovules 18-40 per ovary; plants of waste grounds, disturbed sites.	Cardamine flexuosa
21	Rachises straight; ovules 40-80 per ovary; plants of margins of wet habitats.	Cardamine pensylvanica
22	Rhizomes tuberiform, usually segmented, fragile (segments fusiform, ovoid, oblong, or globose)	> 23
22	Rhizomes cylindrical, segments not fragile	> 29
23	Cauline leaves biternate, distal lobes linear.	Cardamine dissecta
23	Cauline leaves 3-11-foliolate, distal lobes not linear	> 24
24	Cauline leaves 5-11-foliolate.	Cardamine penduliflora
24	Cauline leaves usually 3-, sometimes 5-7-foliolate, rarely simple	> 25
25	Rhizomes moniliform; e, c United States	> 26
25	Rhizomes not moniliform; Pacific North America	> 27
26	Cauline leaves different from rhizomal leaves, usually alternate, rarely opposite.	Cardamine angustata
26	Cauline leaves similar to rhizomal leaves, usually whorled or opposite, rarely alternate.	Cardamine concatenata
27	Middle cauline leaves 5- or 7-foliolate; sepals 1.7-2 mm; petals 4-6 mm.	Cardamine occidentalis
27	Middle cauline leaves 3(-5)-foliolate; sepals 3.5-5.5 mm; petals 8-15 mm	> 28
28	Cauline leaves 2-5; stems (2-)2.7-6(-7) dm; ovules 12-22 per ovary; petals white or pale rose; California.	Cardamine californica
28	Cauline leaves 1-3; stems 0.5-2(-3) dm; ovules 8-16 per ovary; petals usually purple to pale pink, rarely white; British Columbia, California, Oregon, Washington.	Cardamine nuttallii
29	Cauline leaves pinnatisect or (7-)9-21-foliolate	> 30
29	Cauline leaves 3-5(-7)-foliolate	> 31
30	Leaves thick, veins impressed.	Cardamine nymanii
30	Leaves thin, veins raised.	Cardamine pratensis
31	Rhizomes compact at stem base, stolons present.	Cardamine flagellifera
31	Rhizomes slender, stolons absent	> 32
32	Rhizomes fleshy, with dentate leaf scars; plants of North America east of the 110th meridian	> 33
32	Rhizomes not fleshy, without dentate leaf scars; plants of North America west of the 110th meridian	> 34
33	Rhizomes somewhat uniform in diameter; cauline leaves (sub) opposite.	Cardamine diphylla
33	Rhizomes not uniform in diameter (distinctly constricted at intervals); cauline leaves usually alternate, rarely subopposite.	Cardamine maxima
34	Plants cespitose, hirsute; petals purple or pink, rarely white.	Cardamine purpurea
34	Plants not cespitose, glabrous or sparsely pubescent or pilose; petals usually white, rarely pink	> 35
35	Basal leaves rosulate; fruiting racemes subumbellate.	Cardamine umbellata
35	Basal leaves absent; fruiting racemes not subumbellate	> 36
36	Sepals 1.2-1.5 mm; petals 2-2.5 × 0.8-1 mm; anthers 0.2-0.3 mm.	Cardamine holmgrenii
36	Sepals 2-5 mm; petals 3.5-15 × 1.5-8 mm; anthers 0.7-1.5 mm	> 37
37	Rhizomal leaves absent; ovules 14-28 per ovary.	Cardamine breweri
37	Rhizomal leaves present; ovules 6-16(-24) per ovary	> 38
38	Stems hirsute at base; cauline leaves (3 or) 4-8.	Cardamine angulata
38	Stems usually glabrous at base, rarely sparsely pilose; cauline leaves 1-3 (or 4)	> 39
39	Rhizomal leaves palmately or subpalmately compound, fleshy; Montana.	Cardamine rupicola
39	Rhizomal leaves pinnately compound, not fleshy; Alaska, Northwest Territories, Yukon	> 40
40	Rhizomal leaves with terminal leaflet blade broadly obovateto suborbicular, margins often 3-5-toothed.	Cardamine blaisdellii
40	Rhizomal leaves with terminal leaflet blade linear, narrowly oblong, narrowly oblanceolate, ovate, or elliptic, margins entire	> 41
41	Cauline leaves with terminal leaflet narrowly lanceolate to linear, 1-3.2(-4) cm.	Cardamine digitata
41	Cauline leaves with terminal leaflet ovate to elliptic, 0.6-1.3 cm.	Cardamine microphylla