Caltha palustris marsh marigold Ranunculaceae CAPA2; Bx, pb (DeCandido 2001); NY (DeCandido 2001); Q (DeCandido 2001); R (DeCandido 2001); (some of these are probably planted);


Caltha palustris.Eleanor

Caltha palustris.© 2001 Eleanor (Accessed 5/2014).

Caltha palustris is a perennial herb, to 60 cm tall, poisonous when fresh. Contains an unstable oil, protoanemonin (Kingsbury 1964). Stems hollow, branched above. 

Leaves alternate, broadly heart-shaped to kidney-shaped, base deeply lobed, with broad sinus, tip rounded, margin toothed, lower leaves long-stalked, upper becoming almost stalkless. 

Flowers bright yellow, to 4 cm wide, sepals 5-9, petal-like, stamens numerous, April-June. 

Fruit dry, clusters of dry narrow capsules to 1.5 cm long. 

Wetland status: OBL. 

Frequency in NYC: Infrequent. 

Origin: Native. 

Habitat: Along open streamsides, pond edges. 

Notes: Sometimes confused with Ranunculus ficaria (lesser celandine), an upland, non-native, aggressively colonial plant.