Brewer's Cinquefoil

Potentilla breweri

Synonyms: Potentilla breweri var. breweri, Potentilla breweri var. expansa, Potentilla drummondii ssp. breweri, Potentilla drummondii var. breweri

The photo at right shows a close-up of the upper stem, bracts and calyx of Brewer's cinquefoil from along the South Loop Road, approximately 1 mile below its intersection with the North Loop Road on the Steens Mt., southeastern Oregon..........July 16, 2000.

Brewer's cinquefoil is an attractive perennial with simple to slightly branched stems which are spreading to ascending. The herbage is usually grayish woolly, especially on the lower leaf surfaces. The leaves are usually grayish-white in appearance when held at arm's length. No glands are present. The basal leaves are pinnately compound with 9-11 crowded leaflets, although 7-15 may be present. Each leaflet is obovate-cuneate in shape and from 1-2 cm long. The leaflet meargins are deeply and unevenly cut into divergent, oblong lobes cut more than one-half the distance into the midvein. Two to three stem leaves may be present, and these are much reduced in size.

The inflorescence is an open cyme with several flowers. The hypanthium is saucer-shaped. The 5 yellow petals are obovate to obcordate in shape and longer than the sepals. There are 20 stamens and numerous pistils.

Brewer's cinquefoil is similar to, and often found amongst varying cinquefoil (Potentilla versicolor). Both species will form hybrids. The latter species has mature leaves which are sparsely haired to nearly glabrous. They will appear green at arm's length. The leaflets generally number more than 12 and are deeply and unevenly cut into linear to oblong lobes.

Brewer's cinquefoil may be found growing in moist meadows and along stream banks in alpine to midmontane habtiats.

Brewer's cinquefoil may be found from the northern Oregon Cascades south through the Siskiyou Mts. to the Sierra Nevada of California and east to southeastern Oregon and central Nevada.

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