Oenothera macrocarpa subsp. fremontii
Ann. Missouri Bot. Gard. 70: 194. 1983.
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.