[Horsebrush: The Genus Tebradymia East of the Cascade
Mts. of Oregon and Washington]
Gray Horsebrush, Spineless Horsebrush
Tetradymia canescens
Synonym: Tetradymia inermis
A close-up of the inflorescence of gray horsebrush as photographed in prairie and scabland along Wilson Creek, a BLM site several miles south of US Highway 2 in central Washington.........June 25, 2006.
Characteristics:
Gray horsebrush is a much-branched, unarmed shrub from 20 to
60 cm tall. The twigs, leaves, and flower involucres are notably white-tomentose.
The leaves are linear or oblanceolate, measuring from 1-3 cm long and 1-4 mm
wide. The leaf tips narrow abruptly to a narrow spine-like tip. The leaves are
often closely ascending or appressed to the twig (See photo at right.). The
leaves are deciduous in the autumn.
The flower heads are in small cymes at the ends of the numerous
short branches, with 4 (occasionally 5) flowers in each head. The involucres
are about 7-10 mm high and consist of 4 tomentose, oblong bracts.
Habitat:
Gray horsebrush is found in open, dry places in the foothills
and plains.
Range:
Gray horsebrush is found from southern British Columbia east
to Montana, and south through the Pacific Northwest to California, and hence
eastward to New Mexico.
The photo above shows a close-up side view of the flowerheads of gray horsebrush. Note the long, narrow involucral bracts at the base of each flowerhead. Photographed in prairie and scabland along Wilson Creek, a BLM site several miles south of US Highway 2 in central Washington..........June 25, 2006.
Gray horsebrush as seen at Rimrock Lake in Moses Coulee, central Washington.......June 7, 2009.
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Gray horsebrush as seen in bloom at the western base of Dry Falls Dam, Coulee City, Washington.........June 2, 2013.
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Gray horsebrush as seen at left along the Rimrock Springs Trail #850, Crooked River National Grasslands.........June 24, 2017. The photo at right shows what might be the stem and leaves of gray horsebrush along the Alder Springs Trail #855, Crooked River National Grasslands.......May 11, 2018.
Tetradymia canescens found along the road to Blue Sky, Hart Mt. National Antelope Refuge........June 29, 1997.
The photo above shows a side view of the inflorescence and upper stem leaves of gray horsebrush as found at Cow Lakes C.G., BLM, SE Oregon.........June 27, 1999.
The photo above shows a side view of the inflorescence of gray horsebrush as found along US Highway 26 through
the Warm Springs Indian Reservation.........June 26, 1997.
Paul Slichter