Oenothera gaura

W. L. Wagner & Hoch

Syst. Bot. Monogr. 83: 212. 2007.

Basionym: Gaura biennis Linnaeus Sp. Pl. 1: 347. 1753
Treatment appears in FNA Volume 10.

Herbs usually robust winter-annual, sometimes biennial, usually moderately to densely villous, rarely short-hirtellous, also glandular puberulent; from fleshy taproot. Stems usually well-branched distal to base, 50–180 cm. Leaves in a basal rosette and cauline, basal 8–20 × 1.5–3 cm, blade oblanceolate, margins irregularly toothed to lobed; cauline 1.5–12 × 0.5–3 cm, blade narrowly elliptic to elliptic or lanceolate, margins subentire or undulate-denticulate. Flowers 4-merous, zygomorphic, opening at sunset; floral tube 6–13 mm; sepals 5–13 mm; petals white, fading pink to red, narrowly elliptic-obovate, 6–12 mm; filaments 5–10 mm, anthers 2–4 mm, pollen 35–65% fertile; style 12–15 mm, stigma surrounded by anthers. Capsules ellipsoid, 4-angled, 5–9 × 2–3 mm; sessile. Seeds 3–6, light to reddish brown, 2–2.5 × 1–1.3 mm. 2n = 14.


Phenology: Flowering Jun–Oct.
Habitat: Open woods, fields, along streams, disturbed sites, ditch banks, roadsides, railway embankments.
Elevation: 100–600 m.

Distribution

Ont., Que., Conn., Del., D.C., Ill., Ind., Iowa, Ky., Md., Mass., Mich., Minn., N.J., N.Y., N.C., Ohio, Pa., Tenn., Vt., Va., W.Va., Wis.

Discussion

Oenothera gaura is a PTH species and forms a ring of 14 chromosomes in meiosis. It is self-compatible and autogamous (P. H. Raven and D. P. Gregory 1972[1973]), and may have been derived from O. filiformis.

Selected References

None.

Lower Taxa

None.
... more about "Oenothera gaura"
Warren L. Wagner +
W. L. Wagner & Hoch +
Gaura biennis +
Ont. +, Que. +, Conn. +, Del. +, D.C. +, Ill. +, Ind. +, Iowa +, Ky. +, Md. +, Mass. +, Mich. +, Minn. +, N.J. +, N.Y. +, N.C. +, Ohio +, Pa. +, Tenn. +, Vt. +, Va. +, W.Va. +  and Wis. +
100–600 m. +
Open woods, fields, along streams, disturbed sites, ditch banks, roadsides, railway embankments. +
Flowering Jun–Oct. +
Syst. Bot. Monogr. +
Gaura sect. +  and Pleurostemon rafinesque +
Oenothera gaura +
Oenothera subsect. Gaura +
species +