Oenothera argillicola Mack.

• Authority

  Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

• Family

  Onagraceae

• Scientific Name

  Oenothera argillicola Mack.

• Description

  Species Description - Biennial or short-lived perennial to 1.5 m, glabrous or nearly so throughout, or somewhat hairy in the infl, or the lvs minutely puberulent; lvs narrow, the basal narrowly oblanceolate, to 30 × 2 cm, the cauline varying to narrowly lanceolate or lance-elliptic, seldom over 15 × 1.5 cm; infls spicate and ± leafy-bracteate, the tip nodding; hypanthium 3.5–4.5 cm; sep 2–4 cm, the appendages 3–7 mm, subterminal as in no. 2 [Oenothera parviflora L.]; pet 2–4 cm; anthers 8–12 mm; style 2–3.5 cm; fr 2–3 cm, tapering upwards, half as thick at the top as at the base; seeds 1–1.5 mm, prismatic-angled; 2n=14. Shale-barrens; n. Pa. to w. Va. and e. W.Va. July–Sept.

• Common Names

  shale-barren evening-primrose