Watch for marsh marigolds

by KEVIN STRAUSS

While it is a bit early for many spring wildflower to show their colorful heads, keep your eyes open for the yellow marsh marigolds (Caltha palustris). These 8-18 inch tall plants have flat round (or “kidney-shaped”) leaves and yellow flowers. Marsh marigolds often open the last week of April creating a “yellow brick road” in dreams and “gold carpet” in wetlands. But while we see marsh marigolds as yellow, animals who can see ultraviolet (UV) light like bees and flies see the flowers as having black centers and black lines running from the the petals to the center. Entomologists think that those UV markings act as guides to attract pollinators like bees to the center of the flower.

While this flower’s Latin name literally means “marsh marigold,” it isn’t really a marigold, it is more closely related to the buttercups. This is often a problem with “common names.”

By opening their flowers early, marsh marigolds attract the first insect pollinators of the year. While early growth can also attract early feeding by herbivores, marsh marigolds come protected with two potent toxins that cause stomach and heart difficulties for some consumers. But in the constant evolutionary “arms race” of nature, some herbivores like deer and moose have adapted to these toxins. Perhaps these animal’s use their four-part “ruminant” stomachs help them neutralize or at least weaken these poisons. But as time passes, if deer and moose consume most of the marsh marigold plants, this plant may develop an additional toxin or other defense to discourage these large herbivores.

Some people are allergic to the chemicals on the plant surface. For those people, just touching the plant can leave blisters on some people’s skin. The allergy isn’t as common as the widespread allergy to poison ivy, but it is another defense for this early spring plant.

Even though marsh marigolds reproduce with seeds, they are perennials, meaning that each individual plant lives for many years. When winter comes, these plants die back to their starchy root or rhizome. As soon as wetlands thaw and soil warms, the marsh marigold shoots up its leaves and flowers.

So as you are walking or driving around, keep your eyes open for our first spring flowers.