Oenothera macrocarpa subsp. fremontii

(S. Watson) W. L. Wagner

Ann. Missouri Bot. Gard. 70: 194. 1983.

Basionym: Oenothera fremontii S. Watson Proc. Amer. Acad. Arts 8: 587. 1873
Synonyms: Megapterium fremontii (S. Watson) Britton
Treatment appears in FNA Volume 10.

Herbs densely strigillose. Stems numerous, with numerous short secondary branches, 3–30 cm. Leaves gray, (2.8–)3.7–11 × 0.1–0.6(–1.5) cm; blade linear to narrowly elliptic to narrowly elliptic-lanceolate or narrowly oblanceolate, margins flat, entire or inconspicuously denticulate, apex acute. Flowers: buds with unequal free tips 1–2(–5) mm; floral tube (21–)35–65(–80) mm; sepals (20–)25–30(–37) mm; petals (17–)25–33(–37) mm; filaments 13–18 mm, anthers 10–12 mm; style (45–)55–80(–98) mm. Capsules ellip­soid to narrowly ellipsoid, often twisted, wings 2–5(–9) mm wide, body 13–30(–65) × 2–6 mm. 2n = 14.


Phenology: Flowering May–Aug.
Habitat: Rocky soil derived from fine-textured sandstone, shale or chalk on rocky hillsides, bluffs, badlands.
Elevation: 400–900 m.

Discussion

Subspecies fremontii occurs from Franklin and Webster counties in south-central Nebraska south into Kansas to Ellsworth, Hodgeman, and Logan counties; also with disjunct locations in Antelope and Cedar counties in northeastern Nebraska, and Barber County in south-central Kansas. Some specimens from the eastern part of the range, where subsp. fremontii and subsp. macrocarpa are sympatric, appear intermediate between the two subspecies and are difficult to assign.

Selected References

None.

Lower Taxa

None.
Warren L. Wagner +
(S. Watson) W. L. Wagner +
Oenothera fremontii +
Kans. +  and Nebr. +
400–900 m. +
Rocky soil derived from fine-textured sandstone, shale or chalk on rocky hillsides, bluffs, badlands. +
Flowering May–Aug. +
Ann. Missouri Bot. Gard. +
Megapterium fremontii +
Oenothera macrocarpa subsp. fremontii +
Oenothera macrocarpa +
subspecies +