Oenothera oakesiana (A.Gray) J.W.Robbins ex S.Watson & Coult.
Family: Onagraceae
Oakes' evening-primrose
[Oenothera angustissima R.R.Gates,  more...]
Oenothera oakesiana image
John E. Maunder  
Oenothera oakesiana image
from USDA Plants website  
Etymology: Oenothera: from Greek oinos, "wine," and thera, "to imbibe," because an allied European plant was thought to induce a taste for wine
Plants: erect, biennial, 2'-6' tall forb, mostly hairless or only finely fuzzy
Leaves: lance-like to oblong, alternate
Flowers: yellow, 4-parted, 3/4"-1 1/2" wide; inflorescence a terminal, usually unbranched spike nodding at the tip
Fruits: capsule slightly tapering towards top; seeds without tufts of hair at the top
Habitat: disturbed sites
Conservation Status: Native
Oenothera oakesiana image
from USDA Plants website