Common Name: EVENING-PRIMROSE FAMILY
Habit: Annual to perennial herb (to tree). Leaf: cauline or basal, alternate, opposite, or whorled, generally simple and toothed (to pinnately compound); stipules 0 or generally deciduous. Inflorescence: spike, raceme, panicle, or flowers 1 in axils; bracted. Flower: generally bisexual, generally radial, often opening at either dawn or dusk; hypanthium generally prolonged beyond ovary (measured from ovary tip to sepal base); sepals 4(2--7); petals 4(2--7, rarely 0), often fading darker; stamens 2 × or = sepals in number, anthers 2-chambered, opening lengthwise, pollen interconnected by threads; ovary inferior, chambers generally as many as sepals (sometimes becoming 1), placentas axile or parietal, ovules 1--many per chamber, style 1, stigma 4-lobed (or lobes as many as sepals), club-shaped, spheric, or hemispheric. Fruit: capsule, loculicidal (sometimes berry or indehiscent and nut-like). Seed: sometimes winged or hair-tufted.
Genera In Family: 22 genera, +- 657 species: worldwide, especially western North America; many cultivated (Clarkia, Epilobium, Fuchsia, Oenothera). Note: Gaura moved to Oenothera. Fuchsia magellanica Lam. naturalized in northern California.
eFlora Treatment Author: Warren L. Wagner & Peter C. Hoch, family description, key to genera, treatment of genera by Warren L. Wagner, except as noted
Scientific Editor: Robert W. Patterson, Bruce G. Baldwin.

Habit: Annual to subshrub, from taproot. Leaf: basal and cauline, alternate, simple, generally narrowly lanceolate or narrowly elliptic to ovate. Inflorescence: spike, nodding in bud, generally flower from basal-most to distal nodes. Flower: opening at dawn; sepals 4, reflexed singly or in fused pairs; petals 4, yellow, fading red, generally with 1+ red basal spots, with no ultraviolet pattern; stamens 8, longer opposite sepals, anthers attached at middle, pollen grains 3-angled except in polyploid taxa at 20×; ovary chambers 4, stigma +- spheric or hemispheric, exceeding anthers and cross-pollinated or +- = anthers and self-pollinated. Fruit: 4-angled at least when dry, generally proximally thick, contorted or curled 1--5 times, or straight, not swollen by seeds, sessile. Seed: in 1 row per chamber, narrowly obovoid, flattened, dull brown-black.
Etymology: (Greek: like Camissonia) Note: Polyploidy and self-pollination have predominated in evolution of genus. Incl in Camissonia in TJM (1993).
eFlora Treatment Author: Warren L. Wagner
Reference: Wagner et al. 2007 Syst Bot Monogr 83:1--240
Unabridged Reference: Raven 1969 Contr US Natl Herb 37:161--396