The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links
Photo is of parent taxon
Habit Herbs perennial (short-lived or, sometimes, suffrutescent) or annual, glabrous or strigillose; from a stout taproot. Herbs annual or short-lived perennial.Stems 1–several, unbranched or sparsely branched, ascending to erect, 30–80 cm.
Stems

1–many, weakly decumbent to ascending or erect, unbranched to moderately branched, (10–)25–80 cm.

Leaves

1–9 × (0.1–)0.3–1 cm, sometimes fascicles of small leaves to 2 cm present in non-flowering axils;

petiole 0–0.6 cm;

blade linear to narrowly lanceolate or oblanceolate, often folded lengthwise, usually not much reduced distally, proximalmost leaves sometimes spatulate, base attenuate, margins subentire or serrulate or spinulose-serrate, apex acute.

2.5–9 × 0.2–1 cm;

blade margins remotely serrulate to spinulose-serrate.

Flowers

opening at sunrise;

buds with free tips 0–4 mm;

floral tube 5–20 mm;

sepals 4–12 mm, midribs keeled;

petals yellow, fading orangish to purplish, 6–25 mm; antisepalous filaments 2–8 mm, antipetalous filaments 1–4 mm, anthers 2–7 mm, pollen 90–100% fertile;

style 9–30 mm, stigma sometimes blue-black, discoid to quadrangular, exserted beyond anthers.

buds with free tips 0.5–4 mm;

sepals with conspicuously keeled midribs.

Capsules

10–35 × 1–2 mm, hard, dehiscent 1/2 their length, often tardily dehiscent throughout their length.

Seeds

obovoid, 1–1.8 mm, sharply angled, apex truncate.

2n

= 14.

Oenothera capillifolia

Oenothera capillifolia subsp. capillifolia

Phenology Flowering Mar–Sep.
Habitat Prairies, open places in oak savannas on rocky, clay, or sandy soil, often calcareous.
Elevation 0–900 m. (0–3000 ft.)
Distribution
c United States; sc United States; n Mexico
from FNA
LA; OK; TX
Discussion

Subspecies 2 (2 in the flora).

Oenothera capillifolia is self-incompatible (H. F. Towner 1977).

Oenothera berlandieri (Spach) Steudel 1841, not D. Dietrich 1840, is superfluous and cannot be used in Oenothera when transferred from Calylophus, and pertains here.

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

Subspecies capillifolia occurs from Blaine and Lincoln counties, Oklahoma, south through a narrow portion of north-central Texas to central Texas, where it is widely distributed, especially on the Edwards Plateau; also occurring locally in western and southern Louisiana. The floral tubes and/or stigma of some populations, especially from Bexar, Blanco, Comal, Gillespie, Hays, Kendall, Kerr, and Travis counties, Texas, are a deep blackish purple, while others are yellow, which is typical of the section.

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

Key
1. Stems 1–several, ascending to erect, 30–80 cm; leaves 2.5–9 cm.
subsp. capillifolia
1. Stems several–many, decumbent to ascending, (10–)25–40 cm; leaves 1–4 cm.
subsp. berlandieri
Source FNA vol. 10. FNA vol. 10.
Parent taxa Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Calylophus > subsect. Calylophus Onagraceae > subfam. Onagroideae > tribe Onagreae > Oenothera > sect. Calylophus > subsect. Calylophus > Oenothera capillifolia
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. 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. 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. capillifolia subsp. berlandieri
Subordinate taxa
O. capillifolia subsp. berlandieri, O. capillifolia subsp. capillifolia
Synonyms Meriolix capillifolia Calylophus berlandieri subsp. pinifolius, Meriolix hillii, M. melanoglottis, M. serrulata var. pinifolia, O. berlandieri subsp. pinifolia, O. serrulata var. maculatah., O. serrulata subsp. pinifolia, O. serrulata var. pinifolia
Name authority Scheele: Linnaea 21: 576. (1848) unknown
Web links