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

Colorado Springs evening primrose

Habit Herbs robust spring annual or, rarely, surviving a second year, caulescent, hirtellous, also glandular puberulent; from stout taproot.
Stems

ascending to erect, stout, unbranched or with lateral stems from basal rosette, densely leafy, 15–30 cm.

Leaves

10–14(–14.5) × 1.5–2.3(–3) cm;

petiole 4.3–6.6 cm;

blade narrowly oblanceolate, margins irregularly and coarsely dentate, apex acute.

Flowers

usually 5–10 per stem opening per day near sunset, with heavy, sweet scent;

buds erect;

floral tube 31–60 mm;

sepals 17–26 mm;

petals white, fading pale pink, 20–26 mm;

filaments 11–16 mm, anthers 8–11 mm;

style 65–96 mm, stigma exserted beyond anthers at anthesis.

Capsules

straight, lanceoloid, obtusely 4-angled, (21–)25–30(–35) × (5–)6–8 mm, tapering to a sterile beak 6–8 mm, dehiscent 1/2–2/3 their length, valve margins with 5–8 conspicuous, irregular tubercles, sometimes 2 or more coalesced into a sinuate ridge, also with conspicuous medial ridge throughout;

pedicel 0.5–1 mm.

Seeds

numerous, usually in 2 distinct rows per locule, sometimes rows partially overlapping, narrowly obovoid, 2.1–2.3 × 1–1.3 mm, embryo slightly less than 1/2 seed volume, surface appearing finely striate but papillose under magnification;

seed collar with membrane intact at maturity, membrane rarely splitting and separating from collar, margin entire.

2n

= 14.

Oenothera harringtonii

Phenology Flowering May–Jun.
Habitat On compacted, silty clay to looser rocky and sandy soil in open grassland.
Elevation 1400–1900 m. (4600–6200 ft.)
Distribution
from FNA
CO
[BONAP county map]
Discussion

Oenothera harringtonii is known only from southeastern Colorado from western El Paso and eastern Fremont counties, southeast through Pueblo to Otero counties, and south to Las Animas County; it may also occur in adjacent Colfax and Union counties in New Mexico but has not been collected there. Oenothera harringtonii 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.
Parent taxa 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. 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. 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
Name authority W. L. Wagner, Stockhouse & W. M. Klein: Ann. Missouri Bot. Gard. 70: 195. (1983)
Web links