Broad-leaved Caltha, Elkslip, Broadleaved Marsh-marigold, Marsh Marigold, White Marsh-marigold: Caltha biflora (Synonyms: Caltha biflora var. biflora, Caltha howellii, Caltha leptosepala ssp. biflora, Caltha leptosepala ssp. howellii, Caltha leptosepala var. biflora) -
Elkslip, Elkslip Marsh-marigold, White Marsh-marigold: Caltha leptosepala (Synonyms: Caltha biflora var. rotundifolia, Caltha leptosepala var. rotundifolia, Psychropila leptosepala) -