Oenothera macrocarpa
Oenothera cavernae
bigfruit evening primrose, Missouri evening primrose, Ozark sundrop
cave evening-primrose, cavedwelling evening primrose
moderately leafy, (1–)4–40(–60) cm.
(when present) 1–several, ascending, usually unbranched, 2–4 cm.
cauline, (2.8–)3.7–12.5(–17) × (0.1–)0.4–3(–4.5) cm;
petiole (0.4–)1–4(–6) cm;
blade linear, lanceolate-elliptic, elliptic to oblanceolate or suborbiculate, margins entire or conspicuously or inconspicuously denticulate or serrulate, sometimes undulate, apex usually acute, sometimes obtuse or retuse (subsp. incana).
primarily in a basal rosette, sometimes also cauline, (0.5–)2.5–13(–19.5) × (0.2–)0.6–2.3(–2.7) cm;
petiole 0.5–5.2 cm;
blade oblanceolate to elliptic-oblanceolate (in some exceptionally large leaves), margins lyrate-pinnatifid to subentire (in very small ones), apex usually rounded, rarely acute.
usually 1 or 2, rarely more, opening per day near sunset, fading next morning, sometimes (subspp.
1–3(–10) per stem opening per day near sunset, without noticeable scent;
buds sometimes ± recurved before anthesis;
floral tube (20–)30–37(–47) mm;
sepals 4.5–12 mm;
petals white, fading pale pink, (6.5–)8–20(–25) mm;
filaments 5.2–7.5(–12) mm, anthers (1.4–)3–4.5(–6) mm;
style (24–)35–45(–56) mm, stigma surrounded by anthers at anthesis.
papery in age, narrowly ellipsoid to lanceoloid, sometimes twisted (subsp. fremontii), winged, wings (2–)10–28(–34) mm wide, body (13–)25–70(–115) × 2–9 mm, dehiscent 1/4–1/3 their length;
pedicel 1–12(–25) mm.
falcate (especially before maturity), ellipsoid-ovoid to ovoid, obtusely 4-angled, 12–38 × 6–14 mm, tapering to a sterile beak 2–8 mm, dehiscent to 1/2 their length, valve margins with a sinuate ridge or 8–20 nearly distinct tubercles;
pedicel 0–10 mm.
numerous, rarely as few as 8, in 1 row per locule, obovoid, (2–)3–5 × 1–2.3 mm.
usually numerous, sometimes as few as 5, in 2 adjacent rows per locule, obovoid, 2.5–3.1 × 1.1–1.4 mm, embryo 1/2 of seed volume, surface minutely papillose to reticulate;
seed collar without membrane, producing a large empty cavity, margin irregularly sinuate.
and oklahomensis) lasting for 2 days, weakly scented;
buds with unequal free tips 1–11(–15) mm;
floral tube (21–)35–140(–160) mm;
sepals (20–)25–65(–75) mm;
petals bright yellow, fading orange, reddish orange or mostly unchanged, obovate to very broadly obovate, (17–)25–65(–68) mm, usually with terminal notch and/or tooth, margin sometimes erose;
filaments 13–40(–44) mm, anthers 10–24(–25) mm;
style (45–)55–192 mm, stigma usually exserted beyond anthers at anthesis.
= 14.
Oenothera macrocarpa
Oenothera cavernae
Subspecies 5 (4 in the flora).
Oenotheramacrocarpa is variable and has differentiated extensively in the Great Plains region. Each of the five distinctive subspecies occupies a different geographical and ecological situation. Only subsp. mexicana W. L. Wagner from Coahuila, Mexico, occurs outside of the flora area. In general, the subspecies are sharply distinct and each is characterized by a number of features, including pubescence, leaf features, flower and floral tube size, and size and morphology of the capsules and seeds. The five entities are treated as subspecies primarily because of their complete interfertility and extensive intergradation in any area of marginal contact. Intermediates are known between subsp. macrocarpa and subspp. fremontii and oklahomensis and between subspp. incana and oklahomensis. There is also some evidence that suggests past hybridization between subspp. fremontii and incana although there is no present contact between them. All subspecies are self-incompatible.
Oenothera alata Nuttall (1818) is an illegitimate name based on O. macrocarpa and pertains here.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Oenothera cavernae is known from the Arrow Canyon, Las Vegas, and Sheep ranges and the low hills near Arden and Sloan in Clark County, Nevada, eastward along the Grand Canyon to the vicinity of Page, Arizona, and perhaps Washington County, Utah and formerly in Glenn Canyon, and more recently collected in eastern San Bernardino County, California (eastern Clark Mountain Range, and the base of range in Ivanpah Valley). W. L. Wagner et al. (1985) determined O. cavernae to be self-compatible and autogamous.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Herbs glabrous. | → 2 |
2. Leaf blades usually very broadly elliptic to suborbiculate, rarely oblanceolate or elliptic, 2–4.3 cm wide, margins usually entire, sometimes inconspicuously denticulate, usually flat, sometimes undulate. | subsp. incana |
2. Leaf blades usually elliptic to lanceolate-elliptic, sometimes linear, (0.3–)0.8–2(–3) cm wide, margins usually conspicuously denticulate to serrulate, rarely subentire, usually undulate. | subsp. oklahomensis |
1. Herbs strigillose. | → 3 |
3. Bud free tips 1–2(–5) mm; petals (17–)25–33(–37) mm; floral tubes (21–)35–65(–80) mm; capsules often twisted, 13–30(–65) mm, wings 2–5(–9) mm wide. | subsp. fremontii |
3. Bud free tips (4–)5–11(–12) mm; petals (25–)31–65(–68) mm; floral tubes (50–)70–140(–160) mm; capsules not twisted, (28–)30–70(–115) mm, wings 10–28(–34) mm wide. | → 4 |
4. Leaves green or younger ones grayish green, moderately strigillose, rarely more densely strigillose, blades often lanceolate-elliptic to broadly elliptic, sometimes linear or lanceolate, 0.4–2.3(–3) cm wide; capsule wings (14–)18–28(–34) mm wide. | subsp. macrocarpa |
4. Leaves gray, densely strigillose, blades very broadly elliptic to suborbiculate, rarely oblanceolate or elliptic, 2–4.3 cm wide; capsule wings 10–15(–24) mm wide. | subsp. incana |
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