Clusters of 2-3" wide, widely flaring, 4-petalled, primrose yellow flowers are produced in late spring and early summer and are held against a foil of rich green foliage. Northern Sundrops, a selection of our native Oenothera fruticosa ssp. tetragona or sometimes just O. tetragona, is a tough and easy clump forming to short-rhizomatous, herbaceous perennial growing to 2-3' high and potentially to 5'. It is well suited to sunny, average moist to moist, average to well-drained sites. Unlike many of the Evening Primroses, Sundrop flowers are open during the day providing nectar and pollen to a variety of bees, butterflies, and hummingbirds. Item# 13334