Flora of North America species comparison

The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Oenothera pilosella

Oenothera laciniata

meadow evening-primrose

cut-leaf evening-primrose, southern evening primrose
Habit Herbs perennial, usually densely to sparsely hirsute, rarely glabrous; from a thickened base, rhizomatous. Herbs annual, sparsely to moderately strigillose, sometimes also villous, sometimes also becoming glandular puberulent distally.
Stems

spreading or ascending, unbranched or few-branched distally, 20–80 cm.

erect to ascending, unbranched to much branched, 5–50 cm.
Leaves

in a basal rosette and cauline, basal 4–8 × 2–5 cm, petiole (0.5–)1–3(–4) cm, blade oblanceolate to ovate, margins entire;

cauline 3–10(–13) × 1–2(–4) cm, petiole 0–0.5(–2) cm, blade lanceolate to ovate, abruptly narrowed to base, margins subentire or coarsely dentate.

in a basal rosette and cauline, basal 4–15 × 1–3 cm, cauline 2–10 × 0.5–3.5 cm;

blade green, narrowly oblanceolate to narrowly elliptic or narrowly oblong, margins usually dentate or deeply lobed;

bracts spreading, flat.
Inflorescences

erect, flowers in axils of distalmost few nodes.

Flowers

opening near sunrise;

buds with free tips 1–3 mm, spreading;

floral tube 10–25 mm;

sepals 10–20 mm;

petals bright yellow, fading pale pink or pale yellow, 15–30 mm;

filaments 7–15 mm, anthers 4–8 mm, pollen 85–100% fertile;

style 10–20 mm, stigma exserted beyond anthers at anthesis.

usually 1 opening per day near sunset;

buds erect, with free tips erect, 0.3–3 mm;

floral tube 12–35 mm;

sepals 5–15 mm;

petals yellow, fading orange or reddish tinged, broadly obovate or obcordate, 5–22 mm;

filaments 3–14 mm, anthers 4–5 mm, pollen ca. 50% fertile;

style 20–50 mm, stigma surrounded by anthers at anthesis.
Capsules

usually oblong-clavate to oblong-ellipsoid or ellipsoid, 4-angled or weakly 4-winged, (5–)10–15(–28) × 2–4(–5) mm, stipe (1–)3–5(–9) mm;

sessile.

cylindrical, sometimes slightly enlarged toward apex, 20–50 × 2–4 mm.
Seeds

1 × 0.5 mm.

ellipsoid to subglobose, 0.9–1.8 × 0.4–0.9 mm.
2n

= 56.

= 14.

Oenothera pilosella

Oenothera laciniata
Phenology Flowering May–Jul(–Aug). Flowering (Feb–)Apr–Sep(–Oct).
Habitat Open fields, edge of woods, marshes and bottomland prairies, open dis­turbed sites, ditches, old fields, railroads, roadsides. introduced nearly worldwide in temperate and subtropical areas..
Elevation 100–600 m. (300–2000 ft.) 0–1000(–1300) m. (0–3300(–4300) ft.)
Distribution
from FNA
AL; AR; CT; IA; IL; IN; KY; LA; MA; ME; MI; MO; MS; NH; NY; OH; OK; PA; RI; VA; VT; WI; WV; ON
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; CA; CT; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; ND; NE; NJ; NM; NY; OH; OK; PA; RI; SC; SD; TN; TX; VA; VT; WI; WV; WY [Introduced nearly worldwide in temperate and subtropical areas]
[WildflowerSearch map]
[BONAP county map]
Discussion

Oenothera pilosella is widespread in cultivation in gardens and frequently escapes and becomes naturalized; the northern and eastern natural limits of O. pilosella are not clear. According to G. B. Straley (1977) the natural limits are from Wayne County, West Virginia, along the Ohio River and Erie County, New York, for the eastern limits, and Tuscola County, Michigan, and Manitowoc County, Wisconsin, for the northern limits. K. N. Krakos (2014), based on new field studies and phylogenetic data, found that O. pilosella does not form a monophyletic group with plants previously treated by Straley as O. pilosella subsp. sessilis in molecular analyses, and thus is here reinstated as the distinct species O. sessilis. Straley determined that O. pilosella is self-incompatible and an octoploid, one of the few in the genus.

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

Oenothera laciniata is a PTH species and forms aring of 14 chromosomes in meiosis, and is self-compatible and autogamous (W. Dietrich and W. L. Wagner 1988).

Oenothera laciniata is known in New Mexico from Doña Ana and Roosevelt counties from non-montane habitats and thus do not appear to represent O. pubescens; however, a few collections from Brewster and Jeff Davis counties, Texas, reported by W. Dietrich and W. L. Wagner (1988) as O. laciniata appear to represent collections of O. pubescens. Dietrich and Wagner found that O. laciniata hybridizes not only with O. grandis, but also with O. drummondii subsp. drummondii, O. humifusa, and O. mexicana. It is naturalized nearly worldwide in temperate and subtropical areas.

(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. Kneiffia Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Oenothera > subsect. Raimannia
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. platanorum, O. podocarpa, O. primiveris, O. psammophila, 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
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. 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. 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 Kneiffia fruticosa var. pilosella, K. pilosella, K. pratensis, K. sumstinei, O. fruticosa var. hirsuta, O. fruticosa var. pilosella, O. pratensis O. minima, O. repanda, O. sinuata, O. sinuata var. minima, Onagra sinuata, Raimannia laciniata
Name authority Rafinesque: Ann. Nat. 1: 15. (1820) Hill: Veg. Syst. 12(app.): 64, plate 10. (1767)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



Type/paste one or more Latin names into the boxes above; matching taxa will show up below the box as you type. You can use the up/down arrow keys to move through the list.

(If the plant you're looking for doesn't show up in the auto-complete list, that means it either isn't described in Flora of North America yet, or it's listed under a synonym. And please note that Flora of North America is still missing several plant families, including Fabaceae, Apiaceae, Boraginaceae, and Polemoniaceae.)

Choose a data source: Flora of North America

The species comparison tool is brought to you by:
Northwest Wildflowers