General: Aquatic to amphibious, perennial herb, rooting from nodes of lower stems, roots fibrous, slender; stems coarse, freely-branched, floating or creeping, smooth, hollow.
Leaves: Basal leaves rarely present; submerged stem leaves alternate, semicircular to kidney-shaped, 1-7 cm long, 2-11 cm wide, 1- to 6-times parted, lobed, or dissected, the segments entire or round-toothed, tips rounded to thread-like; floating stem leaves absent or unlike submerged, 3-lobed, lobes linear to oblong; stalks 0.5-4 cm long.
Flowers: Inflorescence of 1- to few-flowered terminal and axillary cymes, on stout stalks to 10 cm long; receptacle sparsely stiff-hairy; petals 5-6, distinct, yellow, 7-12 mm long, 5-9 mm wide, nectary on upper surface, the nectary scale variable, 1.5 mm long; sepals 5, spreading or weakly bent back, early deciduous, 5-7 mm long, 3-6 mm wide, smooth; stamens 30-70; pistils 30-70.
Fruits: Achenes, numerous in an egg-shaped head 8-10 mm long, 7-8 mm wide, the achenes egg-shaped, flattened, 1.8-2.2 mm long, 1.6-2.2 mm wide, smooth; beaks persistent, lanceolate, flattened, straight or somewhat curved at tip, 1-1.8 mm long.
Notes: This species is closely related to R. gmelinii.
Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2020. E-Flora BC:
Electronic Atlas of the Plants of British Columbia [eflora.bc.ca]. Lab for
Advanced Spatial Analysis, Department of Geography, University of British
Columbia, Vancouver. [Accessed:
2021-10-18 1:14:44 AM
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