Herbs biennial, densely to sparsely strigillose and villous, with spreading, red-pustulate hairs, also glandular puber­ulent and with only a few appressed hairs near inflores­cence. Stems erect, green or flushed with red on proximal parts, sometimes inflorescence axis red, usually withside branches obliquely arising from rosette and secondary branches from main-stem, 50–150 cm. Leaves in a basal rosette and cauline, basal 13–30 × 3–5 cm, cauline 5–15 × 2.5–4 cm; blade dark to bright green, white or red-veined, narrowly oblance­olate to oblanceolate, sometimes narrowly elliptic to lanceolate distally, margins usually conspicuously crinkled, sometimes undulate, bluntly dentate, teeth widely spaced, sometimes sinuate-dentate proximally or lobed; bracts persistent. Inflorescences erect, unbranched. Flowers opening near sunset; buds erect, 7–9 mm diam., with free tips terminal, erect to spreading, 5–8 mm; floral-tube 35–50 mm; sepals yellowish green, usually flushed with red or red-striped, sometimes very dark red throughout, 28–45 mm; petals yellow to pale-yellow, fading yellowish white and somewhat translucent, very broadly obcordate, 35–50 mm; filaments 17–25 mm, anthers 10–12 mm, pollen ca. 50% fertile; style 50–80 mm, stigma exserted beyond anthers at anthesis. Capsules erect or slightly spreading, dull green when dry, lanceoloid, 20–35 × 5–6 mm, free tips of valves 0.8–1.5 mm. Seeds 1.3–2 ×1–1.5 mm, ca. 50% abortive. 2n = 14.

Phenology: Flowering (Jun–)Jul–Sep(–Oct).
Habitat: Open, disturbed sites.
Elevation: 20–600(–1400) m.

Distribution

• Generated Map
• Legacy Map

Introduced; B.C., Man., N.S., Ont., Que., Ala., Ark., Calif., Conn., Ill., Ind., Maine, Mass., Mich., Mont., N.H., N.J., N.Y., N.C., Oreg., Pa., R.I., Vt., Wash., W.Va., Wis., nearly worldwide in temperate and subtropical regions

Discussion

Oenothera glazioviana originated by hybridization between two cultivated or naturalized species in Europe and was introduced into the horticultural trade by Carter and Company of England in 1860 (R. E. Cleland 1972; P. H. Raven et al. 1979). The oldest name applied to this entity was based on plants cultivated in Rio de Janeiro in 1868; clearly, O. glazioviana must have spread very rapidly.

Oenothera glazioviana is a PTH species and forms a ring of 12 chromosomes and 1 bivalent in meiosis, and is self-compatible and autogamous (W. Dietrich et al. 1997). It has plastome II or III and a AB genome composition.

Selected References

None.

Lower Taxa

None.