The Ozarks Chronicle/Flowers and Native Plants

Wildflower of the month

Missouri primrose grows big, showy blooms

By Dr. Lynda Richards

The Ozark May Queen is Missouri Primrose. These spectacular flowers glow lemon-yellow on limestone glades, dry prairies, and certain roadsides. The plant is rarely over a foot tall, as the stems are somewhat reclining. But the blooms! Each plant opens several of these five-inch beauties in the evening. The flowers last until well into the next morning. But if it happens to be a hot sunny day, the flowers fade to orange and wither by noon . Not to worry! In the evening, more flowers open. Meanwhile, the spent flowers are turning into really nifty big seed pods, green with red spots.

This is the biggest, showiest wildflower associated with the Missouri Ozarks. On a map of the USA , its distribution makes a big splash in southern Missouri and eastern Kansas , with dribbles and droplets in other states from Wyoming to Texas to Tennessee . The particular habitat favored by Missouri primrose is the limestone or dolomite glade. Glades are places where the soil is very shallow, with bedrock outcrops at the surface. In May and June, glades can be very beautiful, with Missouri primrose and pale-purple coneflowers. Later in the season, the going gets tough, very hot and dry. Once in a while you may come across a population of Missouri primrose growing on a well-drained gravel bar. Apparently, glade-like conditions can exist here, with plenty spring moisture and a good drying out later in the season.

Get up close and take a look at the flower structure. There are four huge yellow petals, a central pistil with four crosswise arms, and eight stamens with big yellow anthers. References say that the flowers are pollinated mainly by night-flying sphinx moths, those big hovering moths sometimes mistaken for baby hummingbirds.

Missouri primrose plants can be bought at many nurseries. Two good sources for Missouri stock are Hamilton ’s Native Outpost in Texas County and Missouri Wildflower Nursery just south of Jefferson City . Don’t try to dig Missouri primrose from the wild—the large root usually has grown into a rock crevice and can’t be extricated without damage.

Until recently, the scientific name was Oenothera missouriensis, meaning “the evening primrose of Missouri .” But alas—botanists discovered that the plant had previously been named Oenothera macrocarpa, meaning “the evening primrose with big seed capsules.” Rules for the scientific names of plants dictate that the earliest name must be used.

By November those big seed pods turn a brassy tan. Each pod is about two inches long with four papery wings, the seeds hidden along the middle of the pod. If a pod breaks free of the plant, the wind might roll it away. Thus seeds would be borne to a new site away from the parent plant.

Dr. Lynda Richards, retired Mark Twain National Forest ecologist and a Phelps County Master Gardener, leads Wildflower Walks for the Ozarks River Audubon chapter.