A close-up of the compact inflorescence of petalless saxifrage as seen growing in rocky, vernally moist meadows along the South Loop Road about one mile downhill from the East Rim Viewpoint, Steens Mountain.........August 31, 2011. The flowers typically lack petals, although one to several minute, cream-colored petals which are about half the size of a sepal may be observed on a flower.
Petalless saxifrage is an interesting perennial wildflower with single, leafless stems arising from 10-25 cm high from a cluster of basal leaves. The stems are covered with spreading hairs below and are often glandular hairy above. The leaves are rhombic-lanceolate in shape, narrowing gradually to the broad petioles, The thick blade is usually 2-4 cm in length. The width ranges from 1-2 cm wide but on occasion. The leaf margins are usually entire, but occasionally may be lightly toothed. The margin of the petiole and lower portion of the blade are frequently ciliate.
The inflorescence is a single, dense, capitate cluster of several flowers . The 5 petals may be white, yellowish, or greenish-white, and are often absent. They range from 1-2.5 mm long and oblanceolate or spatulate in shape. Ten stamens, which are shorter than the sepals, are present, five opposite the petals, and five opposite the stamens (See photo at right.). The anthers are often yellow.
Petalless saxifrage at one time was classified as a member of northwestern saxifrage (S. integrifolia), which consisted of 5 separate varieties. Currently, 4 of the varieties have been split from S. integrifolia. Varieties claytoniaefolia, columbiana and leptopetala are now accepted as varieties of S. nidifica. Var. apetala makes up its own species, as does var. integrifolia.
Northwestern Saxifrage Saxifraga integrifolia var. integrifolia: Early spring wildflower to 18 inches tall. Leaves are basal, oval or elliptical in shape, with entire margins. The blades narrow gradually to the short petiole. The flowers are white and generally longer than the sepals. Common in moist banks and seepage slopes which dry out during the summer. Found mostly west of the Cascade Mts. but extending up the Columbia River to Wasco County in Oregon.
Swamp Saxifrage Saxifraga nidifica var. claytoniifolia (S. integrifolia var. claytoniaefolia): The leaves are all basal, the blades broad and abruptly narrowed to the petiole (which is often as long as the blade), the margins generally entire. The petals are white and generally longer than the sepals. Found east of the Cascade Mts. from Okanogan County in Washington south to southern Oregon and east to southeastern Washington, northeastern Oregon, and western Idaho. Also found west in the Columbia River Gorge to the Willamette Valley of northwestern Oregon.
Swamp Saxifrage Saxifraga nidifica var. nidifica (S. integrifolia var. columbiana & var. leptopetala): Leaves all basal with entire margins, the blades rhombic-ovate in shape, narrowed to slender, weakly ciliate or glabrous petioles. . Inflorescence is a cyme with 3-9 branches. The petals are white to greenish-white, up to 2 mm long, and generally shorter than the sepals. Found in the Blue and Wallowa Mts of northeastern Oregon and southeastern Washington, central and southwestern Idaho, and south through southeastern Oregon to northern Nevada and northeastern California.
Petalless saxifrage may be found on moist, grassy slopes and banks in subalpine to alpine habitats.
Petalless saxifrage may be found along the eastern base of the Cascade Mts. from Okanogan County south to Yakima County in Washington and at the Steens Mt. in southeastern Oregon.
Petalless saxifrage growing in rocky, vernally moist meadows along the South Loop Road about one mile downhill from the East Rim Viewpoint, Steens Mountain........August 31, 2011.