Oenothera coronopifolia
Oenothera flava
crownleaf evening primrose
long-tubed evening primrose, yellow evening primrose
ascending to erect, 1–several from base, these unbranched to well-branched, 10–60 cm.
(when present) ascending, 1–several, usually densely leafy, 0–2 cm.
in a weakly developed basal rosette and cauline, 2–7 × 0.2–1.5 cm, axillary fascicles of reduced leaves often present;
blade oblanceolate to oblong, margins usually pinnatifid, sometimes proximal ones coarsely few-toothed.
primarily in a basal rosette, (3.4–)6–30(–36) × (0.5–)1.5–5(–7) cm, flexible, sometimes ± fleshy;
petiole (0.2–)2–7(–10) cm;
blade oblanceolate to linear, margins usually irregularly and coarsely pinnately lobed, rarely subentire, apex acute.
1–3 opening per day near sunset;
buds nodding, weakly quadrangular, without free tips;
floral tube 10–25 mm, mouth conspicuously pubescent, closed with straight, white hairs, 1–2 mm;
sepals 10–20 mm;
petals white, fading pink, ovate or shallowly obcordate, 10–15(–20) mm;
filaments 10–15 mm, anthers 4–7 mm;
style 17–42 mm, stigma exserted beyond anthers at anthesis.
1–4 opening per day near sunset;
buds with free tips (1–)2–10(–12) mm;
floral tube (24–)40–200(–265) mm;
sepals (8–)11–40(–42) mm;
petals bright yellow, sometimes paler (in smaller-flowered plants), fading pale orange, drying purple, (7–)10–45(–50) mm;
filaments (5–)8–23(–26) mm, anthers (2–)3–13(–16) mm;
style (40–)50–250(–290) mm, stigma exserted beyond or surrounded by ring of anthers.
ascending to erect, straight, fusiform, weakly 4-angled, 10–20 × 3–5 mm, dehiscent 1/2 their length;
sessile.
leathery in age, surface usually conspicuously reticulate, usually narrowly ovoid or ellipsoid, sometimes ovoid or lanceoloid, winged, wings narrowly oblong, (2–)3–5(–6) mm wide, confined to distal 2/3 of capsule, (10–)20–35(–43) × 4–8 mm (excluding wings), gradually constricted to a short beak, dehiscent 1/4–1/2 their length, valve surface usually conspicuously reticulate;
sessile.
in 2 rows per locule, ellipsoid to subglobose, 1.5–2 × 1.2–1.5 mm, surface regularly pitted, pits in longitudinal lines.
asymmetrically cuneiform, 1.8–2.2(–2.6) mm.2n = 14.
= 14, 28.
Oenothera coronopifolia
Oenothera flava
Oenothera coronopifolia apparently has both self-incompatible and self-compatible populations (P. H. Raven 1979; W. L. Wagner et al. 2007; K. E. Theiss et al. 2010).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Petals in Oenothera flava typically range from 7–32 mm with floral tubes 24–100 mm; however, plants from three disjunct areas: the Mogollon Plateau in Arizona to Catron County, New Mexico; Sacramento Mountains and Sierra Blanca, Lincoln and Otero counties, New Mexico; and the Sierra Madre Occidental from northern Chihuahua south to Durango, have much larger petals (30–55 mm) and longer floral tubes (80–265 mm). They were originally recognized as a distinct species or most recently as a subspecies (O. flava subsp. taraxacoides), but detailed study of the variation pattern suggests that the larger flowers occur in areas of high hawkmoth species diversity and higher rates of outcrossing, similar to the pattern discussed in detail by D. P. Gregory (1963, 1964). R. A. Raguso et al. (2007) and H. E. Summers et al. (2015) came to the same conclusion in an independent study of floral biology of sect. Lavauxia. Because populations from the three disjunct areas appear to have diverged independently from lower-elevation source populations, it seems best to treat the complex as one variable species without any formal subdivision.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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