“ Stem erect, 6-7 dm. tall, flexuous, somewhat branched, clothed with a pale papery bark; leaves oblong or lanceolate, 4-8 cm. long, obtuse or acute, sinuate-toothed or somewhat pinnatifid, puberulent, with some hispid-villous hairs on the mid-rib and lateral nerves, rather abruptly narrowed into a slender petiole which is less than one centimeter long; flowers few at the ends of the branches, 5-6 cm. broad; calyx hispid-villous, its tube stoutish, 4-4.5 cm. long; nearly thrice longer than the ovary, its segments nearly linear, one-half as long as the tube, the tips free in the bud ”

“ The study has been interesting both from a generic and a specific standpoint in exposing the strong tendency to mass, and to maintain composite species and genera where clear and constant characters exist both in habit and in the more minute morphology. ”

“ OEnothera biennis var. muricata T. & G. Fl. N. A. 1 : 492. 1840.
OEnothera biennis var. canescens T. & G. Fl. N. A. 1 : 492. 1840.
? OEnothera Jepsonii Greene, Fl. Francis. 211. 1891.
Throughout the United States, east of the Rocky Mountains, ranging from sea-level to about 650 meters on various mountains.
The geographic range of O. biennis is not as extensive as has been supposed. The species proper ranges westward only to the Mississippi River. In the area from the Mississippi River to the Rocky Mountains it is represented by a closely related form clothed with strigose pubescence ”