[Mule's Ears: The Genus Wyethia East of the Cascade Mts. of Oregon and Washington]

Rough Dwarf Sunflower, White-rayed Wyethia, White-headed Wyethia

Wyethia helianthoides

Rough Dwarf Sunflower, White-headed Wyethia, White-rayed Wyethia: Wyethia helianthoides

White-rayed wyethia as seen along the Hells Canyon Rim Road in the Hells Canyon National Recreation Area........June 28, 2008.

Characteristics:

White-rayed wyethia looks like a white-flowered balsamroot. Its leaves are both basal and cauline, with the basal ones elliptic or elliptic-ovate in shape and entire margins. The basal leaves ar about 9 - 35 cm in length and about 3 - 12 cm. The reduced stem leaves are often about 6 - 12 cm long and about 1.5 - 4 cm wide. The stems are stout but lax, and the plant often sprawls across the ground. The stems are about 20 to 80 cm long.

The flower heads are mostly single with a spherical involucre. The bracts are nearly linear and acutely tipped (see photo) with numerous hairs on their margins. The rays are white or pale cream in color, and often dry to a yellowish color so they could be misidentified for Wyethia amplexicaulis from a distance. There are most commonly about 13 rays, but as many as 21 may be found on a head. Individual rays range from 2.5 - 4.5 cm in length.

Wyethia helianthoides is similar in appearance to Wyethia amplexicaulis, which has yellow-rayed flowers. Both seem to hybridize where they overlap.


Habitat:

White-rayed wyethia is found from moist and wet meadows at moderate elevations in the mountains. Its bloomtime is approximately May and June in Oregon.


Range:

White-rayed Wyethia is found from central and northeastern Oregon eastward to northern Nevada, Yellowstone Park, and southwestern Montana.


Flower head of Rough Dwarf Sunflower, White-headed Wyethia, White-rayed Wyethia: Wyethia helianthoides - Rough Dwarf Sunflower, White-headed Wyethia, White-rayed Wyethia: Wyethia helianthoides

This photo at left shows a close-up of the white rays and yellow central disk of the flower head of white-rayed wyethia as seen along the Hells Canyon Rim Road in the Hells Canyon National Recreation Area.......June 28, 2008. The photo at right shows the first blooms of white-rayed wyethia as seen in moist meadows along FS Road #42 and Johnson Creek on forest service lands west of Big Summit Prairie, Ochoco National Forest.........April 29, 2016.

Involucre of Rough Dwarf Sunflower, White-headed Wyethia, White-rayed Wyethia: Wyethia helianthoides - Basal leaf of Rough Dwarf Sunflower, White-headed Wyethia, White-rayed Wyethia: Wyethia helianthoides

This photo shows a close-up of the hairy involucre and a leaf of white-rayed wyethia as seen along the Hells Canyon Rim Road in the Hells Canyon National Recreation Area.......June 28, 2008.

Rough Dwarf Sunflower, White-headed Wyethia, White-rayed Wyethia: Wyethia helianthoides - Rough Dwarf Sunflower, White-headed Wyethia, White-rayed Wyethia: Wyethia helianthoides

Vernally moist meadow habitat of Rough Dwarf Sunflower, White-headed Wyethia, White-rayed Wyethia: Wyethia helianthoides - Rough Dwarf Sunflower, White-headed Wyethia, White-rayed Wyethia: Wyethia helianthoides

White-rayed wyethia as seen at Summit Prairie, Malheur National Forest........May 28, 2014.

Flower-filled slope of Rough Dwarf Sunflower, White-headed Wyethia, White-rayed Wyethia: Wyethia helianthoides

A slope filled with white-rayed wyethia as seen along the Hells Canyon Rim Road in the Hells Canyon National Recreation Area.........June 28, 2008.

Rough Dwarf Sunflower, White-headed Wyethia, White-rayed Wyethia: Wyethia helianthoides

A field full of white-rayed wyethia as seen at Summit Prairie, Malheur National Forest, Grant County, Oregon.......June 23, 2011.

Rough Dwarf Sunflower, White-headed Wyethia, White-rayed Wyethia: Wyethia helianthoides - Flower head of Rough Dwarf Sunflower, White-headed Wyethia, White-rayed Wyethia: Wyethia helianthoides

White-rayed wyethia blooming along FS Rd 16 in Logan Valley, Malheur National Forest......June 5, 2011.


Rough Dwarf Sunflower, White-headed Wyethia, White-rayed Wyethia: Wyethia helianthoides - Rough Dwarf Sunflower, White-headed Wyethia, White-rayed Wyethia: Wyethia helianthoides

Early-blooming white-rayed wyethia blooming (left) in moist scablands near the junction of FS Roads #42 and #30 at the southeast corner of Big Summit Prairie, Ochoco National Forest.........April 29, 2016. The photo at right shows white-rayed wyethia blooming at the same location on May 10, 2017..


Rough Dwarf Sunflower, White-headed Wyethia, White-rayed Wyethia: Wyethia helianthoides -  Rough Dwarf Sunflower, White-headed Wyethia, White-rayed Wyethia: Wyethia helianthoides

Rough Dwarf Sunflower, White-headed Wyethia, White-rayed Wyethia: Wyethia helianthoides

White-rayed wyethia blooming on vernally moist scabland habitats along FS Road 4215 about 1.6 miles south of the junction with FS Road 42, Ochoco National Forest...........May 22, 2017.


Rough Dwarf Sunflower, White-headed Wyethia, White-rayed Wyethia: Wyethia helianthoides - Rough Dwarf Sunflower, White-headed Wyethia, White-rayed Wyethia: Wyethia helianthoides

White-rayed wyethia blooming at left on vernally moist scabland habitats along FS Road 4215 about 1.6 miles south of the junction with FS Road 42, Ochoco National Forest...........May 9, 2017. The photo at right shows an early-blooming white-rayed wyethia at Bingham Prairie, near the north trailhead for the Twin Pillars Trail, Mill Creek Wilderness......May 18, 2018.


Rough Dwarf Sunflower, White-headed Wyethia, White-rayed Wyethia: Wyethia helianthoides - Rough Dwarf Sunflower, White-headed Wyethia, White-rayed Wyethia: Wyethia helianthoides

A meadow of white-rayed wyethia beginning to bloom at left at Horse Prairie along spur road 100 just west of FS Road 4230 near the south boundary of the Ochoco National Forest.......May 19, 2018. The photo at right shows white-rayed wyethia in bloom along FS Road 4215 about 100 meters south of the junction with FS Road 4220, Ochoco National Forest.......May 19, 2018.

Paul Slichter