Caltha leptosepala

White Marsh Marigold (Caltha leptosepala)

Marsh marigolds, a sign of spring in the high country

Marsh marigolds remind me of spring and early summer in alpine areas when the deep winter snows start melting. Before the water reaches even the highest headwater streams, it pools on the surface making marshes where these marigolds grow.

The first marsh marigolds start popping out in late May. Within a month or so they’re spread out across the marshes from the edge of the waning snowpack to the sides of surging streams.

Marsh Marigolds (Caltha leptosepala) are part of the buttercup family.

They’re often low, but can grow up to a foot tall. The flowers are about an inch and a half in diameter. They don’t have petals; instead they have a rosette of white sepals, usually between six and a dozen. (Sepals are usually under the petals of flowers in bloom; they cover the petals in the bud). At the center of the flower is a burst of yellow stamens and pistils.

The leaves look a little like upside-down hearts and surround the bottom of the smooth stem. They’re thick and toothed around the edges. Sometimes they curl up like they’re going to form a cylinder.

They range across the western U.S. and Canada from New Mexico to Alaska.

This is a perennial herb growing a mostly naked stem with leaves located basally. The leaves are up to 13 or 15 centimeters long and may have smooth, wrinkled, or toothed edges. The inflorescence bears one or more flowers. Each flower is 1 to 4 centimeters wide and lacks petals, having instead petallike sepalswhich are usually white or sometimes yellow. In the center are many long, flat stamens and fewer pistils.

Masses of yellow stamens brighten the flower center.

"Caltha" is derived from the Greek wordkalathos, "a goblet," a reference to the flower shape. This plant is not a true marigold (which is actually a member of the daisy family), but a marsh-loving buttercup relative. The species name "leptosepala" means slender sepals.

The young leaves are purported to make an excellent potherb by some references, however other authorities warn against eating any part of this species and its Eastern sister species, Caltha palustris, which has been reported to cause toxicity and livestock losses.

Caltha leptosepala is widely distributed in mountainous areas from Alaska south through the Rocky Mountains to Colorado, Utah, and Arizona. It is found westward to northeastern Nevada and southeastern Oregon.