Caltha palustris is a very early blooming wetland species that brightens the forest floor each spring. Its bright yellow flowers seem to almost glow on the damp forest floor. Plant Description and In the Garden sections, below, are courtesy of Shaun Booth of In Our Nature. 

Common Name: Marsh Marigold 

Scientific Name: Caltha palustris 

Family: Ranunculaceae (Buttercup Family) 

Alternate Common Names: Boots, Brave Bassinets, Bull Flower, Cow Lily, Cowslip, Crazy Beth, Crowfoot, Drunkards, Goldes, Gools, Horse Blob, King’s Cup, Mare Blob, Marybuds, May Blob, Meadow Buttercup, Meadow Cowslip, Meadow Gowan, Meadow-bright, Mireblob, Publican’s Cloak, Publicans-and-sinners, Soldier’s Buttons, Water Boots, Water Buttercup, Water Cowslip, Water Dragon, Water Goggles, Water Gowan, Yellow Gowan, Yellow Marsh Marigold (and a whole lot more!) 

Plant description: Marsh Marigold features hairless, hollow, regularly branching stems. The leaves are mostly basal, although a few alternate leaves can be found along the stems. Leaves measure 10cm long and across (alternate leaves are smaller), are round to kidney shaped with a deeply heart-shaped base, have scalloped to toothless edges and a succulent look to them. Small clusters of 2-5 yellow flowers are found on upper stems. Each flower measures 2cm – 4cm across and features 5-9 rounded, waxy, petal-like sepals surrounding a ring of numerous yellow stamens (the part that holds the pollen). 

Flowers give way to clusters of flattened, curved capsules (resembling a jester’s hat) with each capsule measuring about 1cm long. They start out erect and green then curve outwards and become a light brown colour with age. They split open at the top to release greenish brown seeds. 

In the Garden: In early spring, the cheerful yellow flowers of Marsh Marigold glow in enthusiasm for the warmer weather ahead. This plant is easily grown in wet, mucky soil, in the shallow water of a pond or a rain garden. Give it rich soil and never allow it to dry out. It is a well-behaved plant with a low-mounding habit. It spreads by seeds and rhizomes to form colonies but is not an aggressive spreader. Although its name suggests that it is related to marigolds, it belongs to the buttercup family. 

Skill level: beginner 

Lifespan: perennial 

Exposure: full sun to part shade (will tolerate full shade but is less likely to produce flowers) 

Soil Type: muddy, humus-rich soil 

Moisture: wet 

Height: 30-45 cm 

Spread: 30-45 cm 

Bloom Period: Apr, May, Jun 

Colour: yellow 

Fragrant (Y/N): N 

Showy Fruit (Y/N): N 

Cut Flower (Y/N): N 

Pests: no serious insect or disease problems though it may be susceptible to powdery mildew and rust 

Natural Habitat: marshes, swamps, wet meadows and stream margins 

Wildlife value: the nectar and pollen of the flowers attract primarily flies and bees 

Butterfly Larva Host Plant For: none 

Moth Larva Host Plant For: none 

USDA Hardiness Zone: 3-7 

Propagation: [NT, M; D] Seeds should be sown as soon as ripe and cannot dry out before sowing. Seedlings do not flower until the third year following germination. Plants also reproduce easily by division in early spring as the plants are emerging. 

Additional Info: The Latin genus name Caltha comes from the Greek word for “goblet,” and refers to the shape of the flower while the epithet palutris means “of the marsh.” 

Native Range: This widespread plant can be found throughout Canada and in all states surrounding the Great Lakes, as far south as Tennessee and North Carolina, as far west at the Dakotas, and even along the west coast. This is a circumpolar species, found throughout Europe and Asia as well. 

As a consequence of its wide range, it has more common names than any plant I’ve come across – I discovered 60 different common names for this one flower, and that does not include all the variations in spelling for each name. This plant really is the poster child for why we like using the scientific binomial when identifying a species.