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The Fleeting Beauty of Spring Ephemerals

Posted: April 3, 2012

Spring is officially here. Not only did spring warmth arrive early, but the consistently above-average temperatures lasting for several weeks, both day and night-time, have pushed along development of buds and blooms in a short time. Comparing previous years’ entries in my garden journal with this year, we are about three weeks early with flower development.

Each spring in the eastern United States, for a few short weeks, beauty blankets the floor of our deciduous woodlands – the native wildflowers known as spring ephemerals.

One of my favorite spring ephemerals, Twinleaf (Jeffersonia diphylla), is already in bloom in my garden. The lovely white flowers are fleeting, lasting only about a day, so if you blink, you might miss them. But the foliage is also wonderful; each thin stalk bears a deeply divided leaf that looks like a pair of blue-green butterfly wings, unfolding after they emerge. It forms a nice clump in a shaded setting, and if it stays fairly moist in the summer, the foliage remains. But if it gets very dry in summer, the plant will go dormant until the following spring.

Ephemeral means “lasting a markedly brief time,” and indeed these plants emerge, grow, flower, and produce seed in a period of only six to eight weeks; many then enter dormancy and disappear from view until the following spring. They have adapted to take advantage of that short interval between the cold of early spring and the shade of late spring. During this time, the rich soil of the forest floor begins to warm; there is (usually) abundant moisture from melting snow and spring rains; and full sunlight reaches the ground, before the tree leaves overhead have completely expanded to form summer’s shady canopy.

Think of Spring Beauty (Claytonia virginiana), with its bubblegum-pink striped flowers; Squirrel Corn (Dicentra canadensis) and Dutchman’s Breeches (Dicentra cucullaria), both with exquisite blue-green foliage and curious white flowers akin to our familiar garden Bleeding Heart; Trout Lily (Erythronium americanum) with purplish-green mottled foliage and yellow reflexed flowers; Marsh Marigold (Caltha palustris) with cheerfully bright yellow buttercup-like flowers found in swampy marshes in mid April; and Great White Trillium (Trillium grandiflorum) with large and exquisite white three-petaled flowers held above the three leaves of the stalk; and you are thinking of some of our most familiar and beautiful native spring ephemerals.

Many of the spring ephemerals are found along wooded stream banks and many spread over the years to form extensive colonies. These plants have thick, fleshy roots, tubers, or corms that act as underground storage organs to hold nutrients and carbohydrates during the long dormancy period. Some, such as Mayapple (Podophyllum peltatum), Rue Anemone (Anemonella thalictroides), and Celandine Poppy (Stylophorum diphyllum), will delay dormancy until mid to late summer if conditions are favorable, in particular if moisture remains abundant.

Spring ephemerals, besides providing us humans with much-needed early spring color, also serve as an important food source for insects emerging in early spring. Their flowers provide pollen and nectar for beetles, flies, and bumblebees. One spring ephemeral, Toothwort (Dentaria diphylla), is the primary larval food for two native butterflies, the Mustard White and the West Virginia White.

Skunk Cabbage (Symplocarpus foetidus) is the earliest ephemeral to emerge, poking through the leaf litter as early as February. The flowers, tiny and foul-smelling, are held on a spadix, or stalk, covered with a fleshy spotted deep red spathe, or hood. Research has shown that these flowers generate heat enough to raise the temperature inside the spathe 5 degrees F or more above ambient temperatures – enough to melt snow or ice surrounding the flower. What a feast for flies emerging from hibernation – smelly, red, warm – meat? No, but in their thwarted excitement, the flies pollinate the flowers.

One of my favorite sights in April is the sweeping expanse of Virginia Bluebells (Mertensia virginica) along the banks of the Conodoguinet Creek. Their color is described by one author as “the same ethereal blue as a cloudless spring day” – truly a sight worth waiting for each spring.