Oenothera humifusa
Onagraceae subfam. onagroideae
seabeach evening-primrose
erect to decumbent, much branched, 10–50(–90) cm.
in a basal rosette and cauline, basal 4–8 × 0.7–1 cm, cauline 1–7 × 0.3–1.5 cm;
blade usually grayish green, narrowly oblong to narrowly elliptic or narrowly obovate, margins remotely shallowly dentate to subentire;
bracts spreading, flat.
stipules present or absent.
usually 1 opening per day near sunset;
buds erect, with free tips erect and appressed or slightly spreading, 0.5–2 mm;
floral tube 15–35 mm;
sepals3–11 mm;
petals yellow, very broadly obovate or obcordate, 4.5–16 mm;
filaments 4–11 mm, anthers 2–5.5 mm, pollen ca. 50% fertile;
style 23–45 mm, stigma surrounded by anthers at anthesis.
floral tube present or, rarely, absent;
sepals 2 or 4 (very rarely 3), deciduous with floral tube, petals, and stamens;
petals yellow, white, pink, red, rarely in combination.
cylindrical, sometimes slightly enlarged toward apex, 15–45 × 2–3 mm.
usually ellipsoid to broadly ellipsoid, rarely subglobose, 1–2 × 0.5–0.9 mm.
= 14.
Oenothera humifusa
Onagraceae subfam. onagroideae
Oenothera humifusa is a PTH species and forms a ring of 14 chromosomes in meiosis, and is self-compatible and autogamous (W. Dietrich and W. L. Wagner 1988). The inland collection from Iredell County, North Carolina, presumably represents an introduction. There are two geographically separated morphological forms of O. humifusa. Plants of one form are somewhat decumbent, with subentire cauline leaves and bracts; this form occurs in the southern part of the range. The other form is more upright, with more deeply divided leaves; it occurs from North Carolina northward.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Genera 21, species 582 (16 genera, 246 species in the flora).
Onagroideae encompass the main lineage of the family, after the early branching of Ludwigia (R. A. Levin et al. 2003, 2004). This large and diverse lineage is distinguished by the presence of a floral tube beyond the apex of the ovary; sepals deciduous with the floral tube, petals, and stamens; pollen shed in monads (or tetrads in Chylismia sect. Lignothera and all but one species of Epilobium); ovular vascular system exclusively transseptal (R. H. Eyde 1981); ovule archesporium multicellular (H. Tobe and P. H. Raven 1996); and change in base chromosome number from x = 8 in Ludwigia to x = 10 or x = 11 at the base of Onagroideae (Raven 1979; Levin et al. 2003). Molecular work (Levin et al. 2003, 2004) substantially supports the traditional tribal classification (P. A. Munz 1965; Raven 1979, 1988); tribes are recognized to delimit major branches within the phylogeny of Onagroideae, where the branches comprise strongly supported monophyletic groups of one or more genera.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
LA Plants
MD Biodiversity
WildflowerSearch
iNaturalist
USDA Plants Database
