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pink evening primrose, rose evening-primrose

St. Anthony dunes evening primrose

Habit Herbs perennial, caulescent, strigillose and often also sparsely hirsute; from slender taproot. Herbs perennial, caulescent, glabrous, also with resinous exudate, especially on younger leaves; from woody taproot.
Stems

1–several, ascending to decumbent, 7–65 cm.

decumbent, usually branched, 10–30 cm, becoming woody and buried in sand.

Leaves

in a basal rosette and cauline, basal 1–6 × 0.3–2 cm, blade narrowly elliptic to elliptic or ovate, margins subentire, weakly serrulate, or sinuate-pinnatifid;

cauline 1–6 × 0.3–2 cm, blade narrowly elliptic to narrowly ovate, margins subentire or weakly serrulate, proximal ones sinuate-pinnatifid.

(6–)8–9(–14.2) × (0.7–)1.5–2(–3.1) cm;

petiole 3–9 cm;

blade narrowly oblanceolate to oblanceolate, margins usually subentire or repand or remotely dentate, rarely serrate, apex acute.

Inflorescences

erect.

Flowers

1–3 opening per day near sunrise;

buds with free tips 0.1–1 mm;

floral tube 4–8 mm;

sepals 6–12 mm;

petals rose purple, fading darker, 4–12 mm;

filaments 4–6 mm, anthers 2–3.5 mm, pollen 35–65% fertile;

style 7–13.5 mm, stigma surrounded by anthers at anthesis.

1–3 per stem opening per day near sunset, with sweet scent;

buds erect;

floral tube 42–60 mm;

sepals 22–28 mm;

petals white, fading rose pink to rose, 23–40 mm;

filaments 17–19 mm, anthers 13–16 mm;

style 60–72(–88) mm, stigma exserted beyond anthers at anthesis.

Capsules

narrowly obovoid, 4–12 × 2–4 mm, apex attenuate to a sterile beak, proximal stipe 5–20 mm, gradually tapering to base, valve midrib prominent in distal part;

sessile.

somewhat curved and often somewhat twisted, lanceoloid-cylindrical, nearly cylindrical, (20–)30–47 × 7–8 mm, gradually tapering to apex, 6–8 mm, dehiscent nearly throughout their length, valve margins with a conspicuous, irregular, wavy ridge;

pedicel 1–5 mm.

Seeds

narrowly obovoid, 0.5–0.9 × 0.3–0.5 mm.

numerous, in 2 distinct rows per locule, narrowly obovoid, 2.5–3 × 1.2–1.4 mm, embryo 7/8 of seed volume, surface finely reticulate;

seed collar with a broad membrane sealing cavity, margin entire.

2n

= 14.

= 14.

Oenothera rosea

Oenothera psammophila

Phenology Flowering Mar–Sep. Flowering May–Jul.
Habitat tropical areas.. On barren areas of drifting sand at interface between outcrops of lava and sand dunes.
Elevation 10–600 m. (0–2000 ft.) 1500–1700 m. (4900–5600 ft.)
Distribution
from FNA
AZ; CA; TX; Mexico; Central America; West Indies; tropical areas [Introduced in South America (Argentina), Europe, Asia, s Africa, Atlantic Islands (Azores, Canary Islands)]
[WildflowerSearch map]
[BONAP county map]
from FNA
ID
[BONAP county map]
Discussion

Oenothera rosea is a PTH species, forming a ring of 14 chromosomes in meiosis, and is self-compatible and autogamous. In the flora area, it is known from Cochise, Pima, and Santa Cruz counties in Arizona, Alameda, Los Angeles, Riverside, San Bernardino, San Diego, San Francisco, and Santa Barbara counties in California (primarily in urban areas), and from southern Texas. It is clearly of North American origin, since all of its close relatives are confined to North America, and has spread south along the Andes. It occurs at 500–3700 m in South America but generally at lower elevations in most areas.

The name Hartmannia affinis Spach is illegitimate, being based on Oenothera virgata; H. gauroides Spach is also illegitimate, being based on O. rosea; O. purpurea Lamarck is a later homonym; these three names pertain here.

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

Oenothera psammophila is known only from the dune area north and west of St. Anthony, Fremont County. It is unique in Oenothera because of the exudate produced on the leaves to which sand particles adhere, forming a sand sheath, presumably for protection from the constantly blowing sand particles. It is self-incompatible (W. L. Wagner et al. 1985; Wagner 2005).

(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. Hartmannia Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Pachylophus
Sibling taxa
O. acutissima, O. albicaulis, O. argillicola, O. arida, O. arizonica, O. biennis, O. boquillensis, O. brachycarpa, O. calcicola, O. californica, O. canescens, O. capillifolia, O. cavernae, O. cespitosa, O. cinerea, O. clelandii, O. coloradensis, O. cordata, O. coronopifolia, O. coryi, O. curtiflora, O. curtissii, O. deltoides, O. demareei, O. dodgeniana, O. drummondii, O. elata, O. engelmannii, O. falfurriae, O. filiformis, O. filipes, O. flava, O. fruticosa, O. gaura, O. gayleana, O. glaucifolia, O. glazioviana, O. grandiflora, O. grandis, O. harringtonii, O. hartwegii, O. havardii, O. heterophylla, O. hispida, O. howardii, O. humifusa, O. jamesii, O. kunthiana, O. laciniata, O. lavandulifolia, O. lindheimeri, O. linifolia, O. longissima, O. macrocarpa, O. mckelveyae, O. mexicana, O. nealleyi, O. neomexicana, O. nutans, O. nuttallii, O. oakesiana, O. organensis, O. pallida, O. parviflora, O. patriciae, O. perennis, O. pilosella, O. platanorum, O. podocarpa, O. primiveris, O. psammophila, O. pubescens, O. rhombipetala, O. riparia, O. serrulata, O. sessilis, O. simulans, O. sinuosa, O. spachiana, O. speciosa, O. stricta, O. suffrutescens, O. suffulta, O. tetraptera, O. texensis, O. toumeyi, O. triangulata, O. triloba, O. tubicula, O. villosa, O. wolfii, O. xylocarpa
O. acutissima, O. albicaulis, O. argillicola, O. arida, O. arizonica, O. biennis, O. boquillensis, O. brachycarpa, O. calcicola, O. californica, O. canescens, O. capillifolia, O. cavernae, O. cespitosa, O. cinerea, O. clelandii, O. coloradensis, O. cordata, O. coronopifolia, O. coryi, O. curtiflora, O. curtissii, O. deltoides, O. demareei, O. dodgeniana, O. drummondii, O. elata, O. engelmannii, O. falfurriae, O. filiformis, O. filipes, O. flava, O. fruticosa, O. gaura, O. gayleana, O. glaucifolia, O. glazioviana, O. grandiflora, O. grandis, O. harringtonii, O. hartwegii, O. havardii, O. heterophylla, O. hispida, O. howardii, O. humifusa, O. jamesii, O. kunthiana, O. laciniata, O. lavandulifolia, O. lindheimeri, O. linifolia, O. longissima, O. macrocarpa, O. mckelveyae, O. mexicana, O. nealleyi, O. neomexicana, O. nutans, O. nuttallii, O. oakesiana, O. organensis, O. pallida, O. parviflora, O. patriciae, O. perennis, O. pilosella, O. platanorum, O. podocarpa, O. primiveris, O. pubescens, O. rhombipetala, O. riparia, O. rosea, O. serrulata, O. sessilis, O. simulans, O. sinuosa, O. spachiana, O. speciosa, O. stricta, O. suffrutescens, O. suffulta, O. tetraptera, O. texensis, O. toumeyi, O. triangulata, O. triloba, O. tubicula, O. villosa, O. wolfii, O. xylocarpa
Synonyms Gaura epilobia, Godetia heuckii, Hartmannia rosea, H. rosea var. parvifolia, H. virgata, O. psycrophila, O. rosea var. parvifolia, O. rubra, O. virgata, Xylopleurum roseum Pachylophus psammophilusa., O. cespitosa var. psammophila
Name authority L’Héritier ex Aiton: Hort. Kew. 2: 3. (1789) (A. Nelson & J. F. Macbride) W. L. Wagner, Stockhouse & W. M. Klein: Monogr. Syst. Bot. Missouri Bot. Gard. 12: 84. (1985)
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