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Organ Mountain evening primrose

Nuttall's evening primrose

Habit Herbs perennial, moderately hirsute (hairs often with reddish purple, pustulate bases), alsostrigillose and becoming glandular puberulent distally; initially from slender taproot with single rosette, later developing numerous adventitious shoots from taproot and lateral roots, root system then appearing fibrous. Herbs perennial, mostly glabrous, sometimes strigillose on leaves and/or glandular puberulent on distal parts, at least on floral tube; from a taproot, lateral roots producing adventitious shoots.
Stems

weakly erect to ascending, many from base, forming clumps 1–1.5 m diam., often branched distally, 30–60 cm.

erect, often branched, 30–100 cm.

Leaves

in a weakly developed basal rosette and cauline, basal 9–23 × 1–2.5 cm, cauline 5–11 × 1.5–3.5 cm;

petiole 0.5–1.5 cm;

blade very narrowly oblanceolate to narrowly elliptic, margins undulate, remotely and bluntly dentate.

in a basal rosette and cauline, rosette weakly developed or absent, at least during flowering, 2–6(–10.5) × 0.3–0.6(–1) cm;

petiole 0–2 cm;

blade narrowly oblong to oblong-lanceolate, margins usually entire, sometimes remotely denticulate or repand-denticulate.

Flowers

opening near sunset, not strongly scented;

buds with free tips terminal, erect, 3–10 mm;

floral tube straight, 100–165(–190) mm;

sepals 25–50 mm;

petals yellow, fading deep reddish orange, broadly obovate with truncate apex, or obcordate, 30–55 mm;

filaments 18–35 mm, anthers 10–19 mm;

style 140–235 mm, stigma exserted beyond anthers at anthesis.

1–several opening per day near sunset;

buds nodding, weakly quadrangular, with free tips 1–2 mm;

floral tube 15–40 mm;

sepals 20–30 mm, not spotted;

petals white, fading pink, broadly obovate or obcordate,15–30 mm;

filaments 15–18 mm, anthers 8–10 mm;

style 35–45 mm, stigma exserted beyond anthers at anthesis.

Capsules

erect to slightly spreading at acute angle from stem, cylindrical, 25–35 ×4–5.5 mm, dehiscent at least 3/4 their length.

erect or ascending, woody in age, straight or slightly curved, cylindrical, obtusely 4-angled, especially toward base, tapering slightly from base to apex, 20–30 × 2–3 mm;

sessile.

Seeds

numerous, in 2 distinct rows per locule, dark reddish brown, sometimes with darker flecks, obovoid, asymmetrical, irregularly angled, 1.5–2.1 × 1–1.2 mm, surface irregularly pitted and with collapsed papillae.

numerous, in 1 row per locule, reddish dark brown, narrowly obovoid, 1.5–2.3 mm.

2n

= 14.

= 14, 28.

Oenothera organensis

Oenothera nuttallii

Phenology Flowering Jun–Sep. Flowering Jun–Sep.
Habitat In larger rhyolite canyons, along water courses, in eroded basins filled with gravel and rocks. Dry, sandy or rocky prairies, open wooded hillsides, disturbed areas, roadsides.
Elevation 1800–2300 m. (5900–7500 ft.) 500–2200(–2900) m. (1600–7200(–9500) ft.)
Distribution
from FNA
NM
[BONAP county map]
from FNA
CO; IL; MI; MN; MT; ND; NE; SD; WI; WY; AB; MB; SK
[WildflowerSearch map]
[BONAP county map]
Discussion

Oenothera organensis is known only from the Organ Mountains, Doña Ana County, especially on the east side. Various studies have been done to assess the status of this narrow endemic and estimate 2000 to 5000 individuals with wide fluctuations likely due to variation in rainfall (W. Dietrich et al. 1985). Oenothera organensis could decline if degradation of habitat increases in the Organ Mountains. The genetics and population biology of this taxon have been heavily studied in the past (summarized in Dietrich et al.). It is self-incompatible.

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

Oenothera nuttallii had been assumed to be self-incompatible (W. L. Wagner et al. 2007), but K. E. Theiss et al. (2010) determined two plants to be self-compatible.

Anogra nuttalliana Spach and Baumannia nuttalliana Spach are illegitimate names that pertain here.

(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. Oenothera > subsect. Emersonia Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Anogra
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. 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
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. 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 O. macrosiphon O. albicaulis, O. albicaulis var. nuttallii
Name authority Munz ex S. Emerson: Genetics 23: 190. (1938) Sweet: Hort. Brit. ed. 2, 199. (1830)
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