[Evening Primroses: The Genera Camissonia, Chylismia, Chylismiella, Eremothera, Taraxia and Tetrapteron East of the Cascade Mts. of Oregon and Washington]
Diffuseflower Evening-primrose, Diffuseflower Evening Primrose, Long-leaf Evening-primrose, Long-leaved Evening Primrose, Stemless Evening-primrose
Taraxia subacaulis
Synonyms: Camissonia subacaulis, Jussiaea subacaulis, Oenothera heterantha, Oenothera subacaulis
The photo above shows stemless evening-primrose as seenon vernally moist swales along Forest Road #30 southwest of the old Cold Springs Guard Station, Ochoco National Forest.........May 27, 2018.
The
photo at right shows a close-up sideview of the flower and reflexed sepals of
stemless evening-primrose as seen at milepost 8.1 along the Northern Steens Mt.
Loop Road in southeastern Oregon.........5/27/2000.
Characteristics:
Stemless evening-primrose is a perennial wildflower with stout
taproot with a cluster of basal leaves and low flowers. The herbage of the leaves
is mostly glabrous although the leaf margins may have some tiny hairs, or with
widely scattered, appressed hairs on the surface of the blades. The leaves ascend
or spread from the basal rosette and have elliptic to oblanceolate blades which
taper to a definite petiole. The blades range from 5-30 cm long and 1.5-5 cm
wide. Some leaves may have small, narrow lobes near the base of the blades,
but the margins are otherwise entire or lightly toothed.
The numerous flowers are clustered around the center of the
basal rosette, arising from the leaf axils. The flowers open in the morning
and wilt by the end of the day. The floral tube is 1.5-3 mm long and is subtended
by a sterile, pedicel-like neck from 1.5-7 cm long. The 4 sepals are 6-15 mm
long, completely separating and reflexed downwards while in flower. The yellow
petals 7-15 mm long and about as wide with rounded but torn or notched tips.
The 4 filaments are alternately longer and shorter with anthers at their tips
from 1-2.5 mm long. The style is exserted from the floral tube 2-7 mm and capped
by subglobose stigma which may be broadly but shallowly 4-lobed. The fruit is
a sessile capsule from 1.3-2.5 cm long and 5-7 mm wide. In cross-section, the
capsule is quadrangular and each valve has an apparent midrib.
Habitat:
Stemless evening-primrose may be found in meadows and seasonally
moist open areas from the lowlands to about 2900 meters in elevation in the
mountains.
Range:
Stemless evening-primrose may be found in central and eastern
Washington south through central Oregon to east-central California and then
in south-central Nevada, and central Utah.
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Additional close-ups of stemless evening-primrose as seen along Forest Road #4650 east of Dog Fight Corral at the eastern side of Chief Joseph Canyon in the northern Wallowa-Whitman National Forest.........June 26, 2008.
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Stemless evening-primrose as seen at Summit Prairie, Malheur National Forest..........May 28, 2014.
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Stemless evening-primrose as seen in Logan Valley, Malheur National Forest........June 23, 2011.
Stemless evening-primrose as seen along FS Road #2230 on Mount Pisgah, Ochoco National Forest.........June 13, 2015.
The photo above shows stemless evening-primrose as seen along Forest Road #4650 east of Dog Fight Corral at the eastern side of Chief Joseph Canyon in the northern Wallowa-Whitman National Forest.........June 26, 2008.
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Stemless evening-primrose in bloom at left in vernally moist meadows along Indian Creek at the northwestern edge of the Ochoco National Forest.....May 27, 2018. The photo at right shows stemless evening-primrose in bloom along the Umtanum Falls Trail, Yakima County, WA.......May 25, 2019.
The photo above shows the leaf of stemless
evening-primrose as seen at Big Summit Prairie in the Ochoco N.F............May
23, 1998. Note the sinuous, slightly toothed margins.
The photo above shows stemless evening-primrose as seen at milepost
8.4 along the Northern Steens Mt. Loop Road in southeastern Oregon.........5/27/2000.
Paul Slichter
