Annual or short-lived perennial
Reproducing only by seed.
Stems are erect, 5-60cm high, stout, hollow, smooth, branched above and often somewhat succulent.
Basal and lower stem leaves succulent, long-stalked, somewhat kidney-shaped in outline and distinctly 3-lobed to nearly 3-parted, the segments being cleft or lobed or with rounded teeth. The upper leaves are much smaller, commonly either having 3 linear-oblong segments with entire or only slightly toothed divisions, or simple.
Flowers numerous but borne singly on long stalks at the ends of branches, the whole inflorescence being either rounded or elongated; sepals 2-5mm long, with soft hairs; petals pale yellow, 1-5mm long; stamens many in a ring surrounding the many tiny pistils. The seeds individually are very small being about 0.8-1.4mm long, but are very numerous in a short, cylindric cluster. Flowers from May to September.
Celery-leaved buttercup is found in southern and western Ontario in swamps, ditches, roadsides, pastures, fields, mudflats and the edges of ponds and lakes.
It is distinguished by its celery-like, 3-lobed lower leaves having long petioles and rounded teeth, its small, yellow flowers and its elongated cluster of seeds.
Celery-leaved buttercup. A. Plant. B. One flower with many stamens and pistils. C. One seed head with many seeds.