Biennial Gaura
Biennial gaura (Oenothera gaura) is a native, biennial wildflower in Wisconsin, belonging to the evening primrose family. It commonly grows in woodlands, streambanks, disturbed areas, open fields, and roadsides, thriving in habitats ranging from moist to dry. This species plays an important ecological role as a pioneer plant, helping stabilize soil and support biodiversity in recovering ecosystems.
Biennial gaura typically reaches four to six feet tall, with slender, branching stems that may have a reddish or purplish tint, especially toward the top. The roots form a strong taproot, allowing it to tolerate drought and anchor into challenging soil conditions.
Its flowers are white fading to pinkish, with delicate fan-like petals, and bloom from mid to late summer into early fall, making it a valuable nectar source for bees, butterflies, and moths during a time when few native plants are in flower. After blooming, it produces small, dry fruits (achenes) that are dispersed by wind or gravity.
The leaves are rough and oriented vertically, growing in a north-south direction. When fully grown, they are about five inches long and 1½ inches wide. Leaves typically alternate along the stems, though occasionally whorled arrangements occur where new stems emerge from old ones. Leaf shapes range from lanceolate to ovate, with smooth to slightly dentate margins, and are hairy on both surfaces, aiding in moisture retention and resilience. (July)