Cardamine flexuosa |
Cardamine digitata |
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wavy bitter-cress, wood bitter-cress, woodland bitter-cress |
Richardson's bittercress |
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Habit | Annuals or biennials; sparsely to densely hirsute basally or throughout, or glabrous. | Perennials; glabrous throughout. |
Rhizomes | absent. |
cylindrical, slender, 0.5–1.5 mm diam. |
Stems | erect, ascending, or decumbent, branched or unbranched, (0.6–)1–5 dm, (slightly flexuous). |
erect, unbranched, (0.6–)1–2(–3) dm. |
Basal leaves | (often withered by anthesis), not rosulate, 5–15-foliolate, (2.7–)4–14(–19) cm, leaflets petiolulate; petiole 0.7–5 cm, (ciliate or not); lateral leaflet blade oblong, ovate, or elliptic, smaller than terminal, margins entire, repand, crenate, or 3 (or 5)-lobed; terminal leaflet (petiolule 0.3–1.7 cm), blade reniform, broadly ovate, or suborbicular, 0.5–2.5 cm × 4–30 mm, margins repand, crenate, or 3 or 5-lobed. |
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Rhizomal leaves | pinnately 5 or 7-foliolate, (2–)4–10 cm, (not fleshy), leaflets sessile; petiole (1.5–)3–7(–9) cm; lateral leaflets similar to terminal, blade sometimes smaller; terminal leaflet blade linear to narrowly oblong or narrowly lanceolate, (0.5–)1–2.5(–3.3) cm × 0.5–4(–8) mm, base cuneate to attenuate, margins entire. |
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Cauline leaves | 3–15, 5–15-foliolate [leaves (2–)3.5–5.5(–7) cm, including petiole], petiolate, leaflets petiolulate; petiole base not auriculate; lateral leaflets similar to basal, (0.4–2.5 mm wide). |
(1 or) 2 or 3, 5 or 7-foliolate, petiolate, leaflets sessile; petiole (0.2–)0.5–1.2(–1.5) cm, base not auriculate; lateral leaflets similar to terminal, blade smaller; terminal leaflet blade narrowly lanceolate to linear, 1–3.2(–4) cm × 0.8–2.5(–3.5) mm, base cuneate to attenuate, margins entire (apex acute to acuminate). |
Racemes | ebracteate. |
ebracteate. |
Flowers | sepals oblong, 1.5–2.5 × 0.7–1 mm, lateral pair not saccate basally; petals white, spatulate, 2.5–4(–5) × 1–1.7 mm; (stamens rarely 4, lateral pair absent); filaments 2–3 mm; anthers ovate, 0.3–0.5 mm. |
sepals ovate, 2.5–3.5 × 1.5–2.5 mm, lateral pair not saccate basally; petals white, obovate, 5–9 × 2.5–5 mm (clawed, apex rounded); filaments: median pairs 3–4.5 mm, lateral pair 1.5–2.5 mm; anthers oblong, 1–1.5 mm. |
Fruiting pedicels | divaricate or ascending, (5–)6–14(–17) mm. |
suberect to divaricate-ascending, (7–)10–25 mm. |
Fruits | linear, (torulose), (0.8–)1.2–2.8 cm × 1–1.5 mm; ovules 18–40 per ovary; style 0.3–1(–1.5) mm. |
linear, (1.5–)2–4 cm × 1.5–2 mm; ovules 6–12 per ovary; style (1–)1.5–2.5(–4) mm. |
Seeds | brown, oblong or subquadrate, 0.9–1.5 × 0.6–1 mm, (narrowly margined or not). |
brown, oblong, 1.8–2.2 × 0.9–1.1 mm. |
2n | = 32. |
= 28, 42. |
Cardamine flexuosa |
Cardamine digitata |
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Phenology | Flowering Apr–Jul. | Flowering Jun–Aug. |
Habitat | Disturbed areas, fields, nurseries, plantations, gardens, flower beds, lawns, roadsides | Damp flats, stream banks, tundra, meadows, bluffs, hummocks, sandy beaches, slopes, mossy mats, sedge swales |
Elevation | 0-1100 m (0-3600 ft) | 0-1400 m (0-4600 ft) |
Distribution |
AL; CA; FL; GA; IL; IN; LA; MD; MI; NC; NY; OH; OR; RI; TX; VA; WA; BC; NF; ON; Europe; e Asia [Introduced in North America; introduced also in Mexico, Central America, South America, Australia]
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AK; NT; YT; ne Asia (Russian Far East, Siberia) |
Discussion | According to J. Lihová et al. (2006), the populations referred to Cardamine flexuosa in North America comprise two taxa of different polyploid origins and evolutionary histories: tetraploid C. flexuosa (2n = 32), native to Europe, and the octoploid taxon informally called “Asian C. flexuosa” (2n = 64), native to eastern Asia. For the latter, the name C. flexuosa subsp. debilis can be used. Nevertheless, these two taxa should be recognized at species level and the correct name for the Asian species should be sought. Based on available data, both taxa occupy the same habitats in North America, but the Asian taxon is much more widespread. The occurrence of European C. flexuosa was, until now, confirmed only for Washington, where both taxa have been recorded. More detailed studies of the North American distributions of both these weeds are needed. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 7, p. 474. | FNA vol. 7, p. 472. |
Parent taxa | Brassicaceae > tribe Cardamineae > Cardamine | Brassicaceae > tribe Cardamineae > Cardamine |
Sibling taxa | ||
Synonyms | C. flexuosa subsp. debilis, C. flexuosa var. debilis, C. hirsuta subsp. flexuosa, C. scutata subsp. flexuosa | C. digitata var. oxyphylla, C. hyperborea, C. hyperborea var. oxyphylla, C. richardsonii |
Name authority | Withering: Arr. Brit. Pl. ed. 3, 3: 578. (1796) | Richardson: in J. Franklin, Narr. Journey Polar Sea, 743. (1823) |
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