4. ŒNOTHÈRA, L. Evening Primrose.
Calyx-tube prolonged beyond the ovary, deciduous; the lobes 4, reflexed. Petals 4. Stamens 8; anthers mostly linear and versatile. Capsule 4-valved, many-seeded. Seeds naked.—Leaves alternate. Flowers yellow, white or rose-color. (An old name, of unknown meaning, for a species of Epilobium.)
§ 1. Stigma-lobes linear, elongated (except in n. 7); calyx-tube linear, slightly dilated at the throat; anthers linear.
[*] Caulescent annuals or biennials; flowers erect in the bud, nocturnal, yellow, the calyx-tips free; capsules sessile, coriaceous; seeds in two rows in each cell.
[+] Flowers in a leafy spike; capsules stout, oblong, slightly narrowed above.
1. Œ. biénnis, L. (Common Evening Primrose.) Rather stout, erect (1–5° high), usually simple, more or less pubescent and hairy; leaves lanceolate to oblong- or rarely ovate-lanceolate (2–6´ long), acute or acuminate, repandly denticulate, the lowest petioled; calyx-tube 1–2½´ long, the tips of the sepals contiguous; petals ½–¾´ long; capsule more or less pubescent or hirsute.—Throughout the U. S.—Var. cruciàta, Torr. & Gray, with small narrow petals, appears to be merely a rare garden (?) sport. E. Mass.
Var. grandiflòra, Lindl., has petals as long as the calyx-tube (1–2½´ long).—Same range as the type, but not so common east.
2. Œ. Oakesiàna, Robbins. Annual, more slender, not hairy, the puberulence mainly appressed; calyx-tips not contiguous at base; otherwise nearly as in the typical form of the last. (Œ. biennis, var. Oakesiana, Gray.)—Dry places, E. Mass., R. I., and Conn.
[+][+] Flowers in a leafy spike or axillary; capsules linear.
3. Œ. rhombipétala, Nutt. Rarely branching, appressed-puberulent and subcanescent; leaves narrowly lanceolate, acuminate, denticulate, the lowest attenuate to a petiole and rarely pinnatifid, diminishing upward into the close, elongated, conspicuously bracted spike; calyx silky-canescent (tube 1½´ long); petals rhombic-ovate (6–10´ long).—Ind. to Minn. and Ark.