[The Genus Perideridia in the Columbia River Gorge of Oregon and Washington]

Common Yampah, Gairdner's Yampah, Gardner's Yampah, Squawroot, Western False Caraway

Perideridia gairdneri ssp. borealis

Synonym: Perideridia montana

Umbel of Common Yampah, Gairdner's Yampah, Gardner's Yampah, Squawroot, Western False Caraway: Periderida gairdneri ssp. borealis (Synonym: Perideridia montana)

The photo above shows a view downwards onto the top of the umbel of yampah. Note the numerous small white flowers. Photographed at Catherine Creek in the central Columbia River Gorge...........July 7, 2006.

Common Yampah, Gairdner's Yampah, Gardner's Yampah, Squawroot, Western False Caraway: Periderida gairdneri ssp. borealis (Synonym: Perideridia montana)The photo at right shows the upper leaves and several umbels of yampah as seen along the Chief Joseph Trail in the Eagle Cap Wilderness just west of Wallowa Lake..............July 27, 1997. The photo clearly shows the multiple umbels on the same stem.
Characteristics:

Also known as western false caraway and squawroot, yampah is a glabrous perennial wildflower with a slender erect, sinuous stem from 30-100 cm high arising from a cluster of fleshy roots. The leaves are pinnately compound (or occasionally bipinnately compound) and measure from 10-20 cm long with wide petioles. The few, narrowly linear leaflets are 5-15 cm long (See photo above.). The several leaves are evenly spaced along the stems and are only slightly reduced in size upwards on the stem. The lower leaves often wither by the time of flowering.

The inflorescence consists of 3-10 umbels with 8-16 rays measuring up to 6 cm long. Typically, the umbels are each subtended by several awl-shaped bracts. The umbellets are each subtended by several narrow bractlets while the pedicels are 4-6 mm long. The flowers vary from white to pinkish in color and the petals usually have 5-7 evident veins from the base and are notched at the tip. The fruits are broadly oval and measure from 1-3.5 mm long and about as wide. The surface of the fruit is covered with minute ribs.


Habitat:

Yampah may be found on moist to dry, rocky hillsides, woodlands or in moist to dry meadows from the foothills to about 2500 meters of elevation in the mountains.


Range:

Yampah may be found from southern British Columbia south to the east of the Cascade Mts. to northern California and east to the Snake River Plain and Caribou Range of Idaho and northern Nevada and northern Utah. It is found further eat to central Colorado, western South Dakota and southwestern Saskatchewan.

It may be found in the Columbia River Gorge between the elevations of 100'-3000' from near Cape Horn east to the crest of the Columbia Hills in the eastern Columbia River Gorge.


Basal leaf of Common Yampah, Gairdner's Yampah, Gardner's Yampah, Squawroot, Western False Caraway: Periderida gairdneri ssp. borealis (Synonym: Perideridia montana)

Close-up view of the basal leaf of Gairdner's yampah as seen in moist riparian or seep areas that dry by late spring on the Labyrinth, mid-Columbia River Gorge.................April 15, 2010. The basal leaves have often dried and disappeared by the time the plants flower in early summer.

Common Yampah, Gairdner's Yampah, Gardner's Yampah, Squawroot, Western False Caraway: Periderida gairdneri ssp. borealis (Synonym: Perideridia montana) - Inflorescence of Common Yampah, Gairdner's Yampah, Gardner's Yampah, Squawroot, Western False Caraway: Periderida gairdneri ssp. borealis (Synonym: Perideridia montana)

Gairdner's yampah as seen along the trail high above Rowland Lake and the Labyrinth, Columbia River Gorge..........August 29, 2013.

Basal leaves of Common Yampah, Gairdner's Yampah, Gardner's Yampah, Squawroot, Western False Caraway: Periderida gairdneri ssp. borealis (Synonym: Perideridia montana)

Basal leaves of Gairdner's yampah as seen on vernally moist slopes east of Eightmile Creek and above the Crawford Oaks Trailhead, Columbia Hills State Park.........March 23, 2016.

Common Yampah, Gairdner's Yampah, Gardner's Yampah, Squawroot, Western False Caraway: Periderida gairdneri ssp. borealis (Synonym: Perideridia montana)

The photo above shows an upper stem leaf and umbel of yampah as seen on rock outcrops below fairly heavy timber along the Chief Joseph Trail in the Eagle Cap Wilderness just west of Wallowa Lake..............July 27, 1997.

Common Yampah, Gairdner's Yampah, Gardner's Yampah, Squawroot, Western False Caraway: Periderida gairdneri ssp. borealis (Synonym: Perideridia montana)

The photo above shows the long, narrow segments of a stem leaf of yampah as seen along the Chief Joseph Trail in the Eagle Cap Wilderness just west of Wallowa Lake..............July 27, 1997.

Paul Slichter