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Photo is of parent taxon

Fremont's evening primrose

Photo is of parent taxon
Habit Herbs densely strigillose. Herbs glabrous.
Stems

numerous, with numerous short secondary branches, 3–30 cm.

several, unbranched, sometimes with shorter secondary branches, 5–30(–42) 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.

green, usually flecked with reddish purple splotches or reddish tinged, (5.5–)7–11(–12.5) × (0.3–)0.8–2(–3) cm;

blade usually elliptic to lanceolate-elliptic, sometimes linear, moderately thick, fleshy, margins usually undulate, usually conspicuously denticulate to serrulate, rarely subentire, 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.

buds with unequal free tips (5–)6–10(–15) mm;

floral tube (82–)90–140(–147) mm;

sepals 35–60 mm;

petals (38–)42–55(–65) mm;

filaments 24–34 mm, anthers (15–)19–21(–25) mm;

style (120–)140–190 mm.

Capsules

ellipsoid to narrowly ellipsoid, often twisted, wings 2–5(–9) mm wide, body 13–30(–65) × 2–6 mm.

globose to narrowly ellipsoid, not twisted, wings (10–)15–20(–25) mm wide, body 35–55(–75) × 7–9 mm.2n = 14.

2n

= 14.

Oenothera macrocarpa subsp. fremontii

Oenothera macrocarpa subsp. oklahomensis

Phenology Flowering May–Aug. Flowering Apr–Jun(–Sep).
Habitat Rocky soil derived from fine-textured sandstone, shale or chalk on rocky hillsides, bluffs, badlands. Rocky, clay soil, open sites of fine-textured, red sandstone usually mixed with gypsum, on pure gypsum, on limestone.
Elevation 400–900 m. (1300–3000 ft.) 200–500(–800) m. (700–1600(–2600) ft.)
Distribution
from FNA
KS; NE
[BONAP county map]
from FNA
KS; OK; TX
[BONAP county map]
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.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Subspecies oklahomensis is known from Barber, Harper, Meade, and Montgomery counties in extreme southern Kansas south across central Oklahoma to Harmon County in southwestern Oklahoma, and Cooke and Knox counties in adjacent Texas.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 10. FNA vol. 10.
Parent taxa Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Megapterium > Oenothera macrocarpa Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Megapterium > Oenothera macrocarpa
Sibling taxa
O. macrocarpa subsp. incana, O. macrocarpa subsp. macrocarpa, O. macrocarpa subsp. oklahomensis
O. macrocarpa subsp. fremontii, O. macrocarpa subsp. incana, O. macrocarpa subsp. macrocarpa
Synonyms O. fremontii, Megapterium fremontii Megapteriumoklahomense norton, O. macrocarpa var. oklahomensis, O. missourensis var. oklahomensis
Name authority (S. Watson) W. L. Wagner: Ann. Missouri Bot. Gard. 70: 194. (1983) (Norton) W. L. Wagner: Ann. Missouri Bot. Gard. 70: 194. (1983)
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