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''Potentilla hickmanii'' (called Hickman's potentilla or Hickman's cinquefoil) is an endangered perennial herb of the rose family. This rare plant species is found in a narrowly restricted range in two locations in coastal northern California, in Monterey County, and in very small colonies in San Mateo County. This small wildflower, endemic to western slopes of the outer coastal range along the Pacific Ocean coast, produces bright yellow blossoms through spring and summer. This species was formerly thought to be growing in Sonoma County but that population has been recently reclassified as another species, ''Potentilla uliginosa'' and is presumed extinct in that county.〔Barry C. Johnston and Barbara Ertter. (2010) "(''Potentilla uliginosa'' (Rosaceae: Rosoideae), a new presumed extinct species from Sonoma County, California )". ''J. Bot. Res. Inst. Texas.'' 4(1):13-18〕 This plant, along with many other threatened species in the northern California Floristic Province, has been designated as a species meriting protection by the U.S. Government, State of California, local governments and private conservation groups. These designations have led to blueprints for protection of Hickman's potentilla in the form of official endangerment classifications and a species Recovery Plan, the latter promulgated by the U.S. Fish and Wildlife Service. ==Description== ''Potentilla hickmanii'' is a long lived rosetted non-glandular flowering plant with a thick taproot.〔''The Jepson manual: higher plants of California'', Hickman, JC, ed.., University of California Press, Berkeley, Ca. (1993)〕 The stem is prostrate five to forty five centimeters long. Blooming occurs between April and August. The hypanthium is three to six millimeters wide, with yellow obchordate petals six to eleven millimeters in length. Up to ten inflorescences may present in a single organism. Filaments are typically 1.5 to 4.0 millimeters in length, while anthers are only about one millimeter in size; moreover, the pistils generally number about ten and the slender styles are about two to three millimeters long.〔Philip A. Munz, ''A California Flora'', University of California Press, Berkeley, Ca. (1973)〕 The somewhat subglabrous leaves are pinnately compound into generally six paired, palmately cleft leaflets. These basal leaves range from six to twenty five millimeters in length with individual leaflets two to eight millimeters long and about two millimeters wide. There are four to seven leaflets per side, in a separated or overlapped configuration. The leaflets are wedge-shaped, typically having three to four teeth (lobes) and originate from about halfway along the leaf stem. The smooth fruits are approximately two millimeters in diameter, tan in color, looking like miniature watermelon seeds 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Potentilla hickmanii」の詳細全文を読む スポンサード リンク
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