The World Flora Online

Plants with numerous fleshy roots. Stems 10--120 cm tall at fruiting, (1.5--)3--12 mm in diam., branched, rarely simple, basal leaves 3--7, long petiolate; petiole (4--)7--24 cm; leaf blade orbicular to orbicular-reniform or cordate, (1.2--)2.5--5 × (2--)3--9 cm, base deeply cordate, margin densely denticulate, apex rounded. Cauline leaves usually diminishing upward, rarely equal to basal leaves in size, orbicular-reniform or triangular-cordate, shortly petiolate or uppermost ones sessile. Monochasium often solitary, (2 or)3--5-flowered; pedicels more than 1.5 cm at fruiting. Flowers 2--3 cm in diam. Sepals 5, yellow, obovate to narrowly obovate, 1--1.8(--2.5) × 0.6--1.2(--1.5) cm, apex rounded. Stamens 4.5--7(--9) mm; anthers sessile, oblong, 1--1.6 mm. Follicles (5--)7--25, ca. 1 cm × 3 mm; persistent style 1--3 mm. Seeds black, rarely pale greenish brown, narrowly ovoid, 1.5--2 mm. Fl. May--Sep. 2n = 16, 32, 55--57, 60, 64, 80.

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• 1
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Stems leafy, permanently erect, or sprawling with age and producing roots and shoots at nodes. Basal leaves: blade rounded to ovate, reniform, or cordate, largest (0.5-)2-12.5 × (1-)2-19 cm, margins entire or crenate to dentate. Inflorescences 1-7-flowered. Flowers 10-45 mm diam.; sepals yellow or orange, (6-)10-25 mm. Follicles 5-15(-25), spreading, sessile, ellipsoid; bodies 8-15 × 3-4.5 mm; style and stigma straight or curved, 0.5-2 mm. Seeds elliptic, 1.5-2.5 mm. 2n=32, 56, 60.

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• 2
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Perennial, stem stout 15-60 cm high, ascending, rarely documbent, with densely fibrous root-stock. Basal leaves long petioled, 7-12 cm wide, entirely or finely or coarsely toothed upper ones and sessile. Flowers yellow rarely white, 2.5-5 cm in diameter. Sepals 5-6, petaloid, ± obovate-oblong or lanceolate. Follicles variable in number with variable length of style. Seeds oblong, black, ± shining.

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• 3
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Stems hollow, 2–6 dm, branched above; basal lvs long-petioled, the broadly cordate-rotund blade usually with a deep and narrow sinus; cauline lvs with progressively shorter petiole and wider sinus; fls bright yellow, 1.5–4 cm wide; stamens 50–120; anthers linear-oblong or lance- oblong, 2 mm; follicles 4–15, 10–15 mm; 2n=32. Wet woods and meadows, swamps, bogs, and shallow water; circumboreal, s. to Va., W.Va., Ind., Ill., and Io., and in the mts. to N.C. and Tenn. Apr.–June. Forms with the basal leaves somewhat flabellate, with a relatively broad and open sinus, do not appear to be taxonomically separable. (var. flabellifolia)

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Bis 50 cm hohe Sumpfpflanze mit ungeteilten, herz- oder nierenförmigen Blättern und dottergelben Blüten, diese meist mit 5 Blumenblättern und zahlreichen Staubblättern. Keine Honigblätter. Früchtchen 3–8, 2- bis mehrsamig, nach aussen gebogen.

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• 5
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3–5. Bachufer, Sumpfwiesen, kollin-subalpin(-alpin). CH.

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• 5
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SELECTED REFERENCES

Smit, P. G. 1967. Taxonomical and ecological studies in Caltha palustris L. (preliminary report). Proc. Kon. Ned. Akad. Wetensch. C. 70: 500-510. Smit, P. G. 1968. Taxonomical and ecological studies in Caltha palustris L. II. Proc. Kon. Ned. Akad. Wetensch. C. 71: 280-292. Woodell, S. R. J. and M. Kootin-Sanwu. 1971. Intraspecific variation in Caltha palustris. New Phytol. 70: 173-186.

Source: [
• 2
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