[Evening Primroses: The Genera Camissonia, Chylismia, Chylismiella, Eremothera, Taraxia and Tetrapteron East of the Cascade Mts. of Oregon and Washington]
Tansyleaf Evening Primrose, Tansy-leaf Evening Primrose, Tansy-leaved Evening Primrose
Taraxia tanacetifolia
Synonyms: Camissonia breviflora, Camissonia tanacetifolia, Camissonia tanacetifolia ssp. tanacetifolia, Oenothera breviflora, Oenothera tanacetifolia, Taraxia breviflora, Taraxia tanacetifolia ssp. tanacetifolia
Tansy-leaved evening -primrose from along the Long Hollow Pass Road about one and one-half miles west of the pass, Steens Mountain, Harney County, Oregon........June 31, 2012.
Characteristics:
Tansy-leaved evening-primrose is an attractive, medium-sized
and weed-like wildflower. The herbage varies from a dense covering of small,
coarse, stiff hairs to covered with appressed hairs or sometimes nearly glabrous.
Its leaves are largely basal. They are narrowly to broadly lanceolate to oblanceolate,
deeply sinuate-pinnatifid, and range from 5 to 20 cm long and 10 to 35 mm wide.
The petioles narrow gradually to the base, and are from one-half to as long
as the leaf blade.
The flowers are bright yellow, sometimes aging to purple. They
are found in the axils of the leaves and are adapted from cross-pollination.
They are rounded in shape and 10 to 16 mm long. The sepals are separately reflexed
sharply downward and range from 6-13 mm long. The floral tube is 3-7 mm long
while the style is exserted 5-13 mm above the floral tube. The stigma is sublobose
or broadly and shallowly 4-lobed. The stamens are unequal in length, with the
longest about half the length of the petals. The capsule is sessile, lanceolate-fusiform
in shape and widest below the middle. The capsule varies from 1-2.5 cm long
and 3-4.5 mm wide.
Habitat:
Tansy-leaved evening-primrose is found in moist soil in meadows,
swales, riverbanks, and alongside roads from riverbanks to sagebrush plains
and ponderosa pine forests.
Range:
Tansy-leaved evening-primrose is found from Washington south
along the eastern edge of the Cascades to the Sierra Nevada of California, and
eastward to Idaho and Montana.
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Tansy-leaved evening-primrose observed on the shoreline of Thompson Reservoir at East Bay Campground, south of Silver Lake, OR.......June 18, 2020.
Tansy-leaved evening primrose as seen along the Steens Mountain North Loop Road about one mile downhill from the upper limit of the juniper forest along the road........June 2, 2012.
Tansy-leaved evening -primrose from along the North Loop Road about one-half mile south of the Kiger Gorge Overlook, Steens Mountain, Harney County, Oregon.........August 31, 2011.
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Additonal close-up photos of tansy-leaved evening -primrose from along the North Loop Road about one-half mile south of the Kiger Gorge Overlook, Steens Mountain, Harney County, Oregon.........August 31, 2011.
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Tansy-leaved evening-primrose as seen along FS Road #27 in Thompson Valley, Fremont National Forest..........May 19, 2016.
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Tansy-leaved evening-primroses along the North Loop Road above the junction with the Kiger Gorge Overlook Road on the Steens Mountain..........September 20, 2015.
Basal leaf rosettes of tansy-leaved evening-primrose as observed in vernally moist scablands near the junction of Forest Roads 42 and 30, southeast corner of Big Summit Prairie, Ochoco National Forest.......May 13, 2018.
Paul Slichter