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3 <br /> More detailed information regarding the habitat of L. bradshawii can be <br /> found in Kagan (1980), and the Recovery Plan ( USFWS 1993). <br /> Life History <br /> Peak blooming period occurs the last week in April through the first <br /> week in May. It is easily distinguished because it is the only yellow <br /> flower blooming in Willamette Valley grasslands in mid April to mid <br /> May(Kagan 1980). Flowers are produced on umbels. Each plant usually <br /> produces one, sometimes two, umbels per plant. Kagan (1980) found <br /> approximately 90% of the flowers produced are male with some plants <br /> producing hermaphroditic umbels, usually the second umbel produced on a <br /> plant. He also found that more than half (50.9 %) of the plants observed <br /> at Willow Creek Preserve were sterile. <br /> L. bradshawii reproduces only by seed. Po li130ion method is not <br /> entirely known but may be through inse ts - pollination, or wind and <br /> rain. Kagan (1980) observed few pol „k'ato,i and d suggested that <br /> the plants observed were often "sel ng ' re present from late <br /> May to early June (Kagan 1980) and 1 roppe•': pon maturity. Seeds <br /> fall to the ground and may be distrio ed by flood waters, but this has <br /> not been confirmed. <br /> More detailed information rega ;in.'i:tiellfe history of L. bradshawii <br /> can be found in Kagan (1980) an• he Recovery Plan (USFWS 1993). <br /> i a <br /> Status ' 0 <br /> x kA <br /> Fourteen distinct •■•ulat ns L. bradshawii currently occur in four <br /> areas of the Wiliam teVal ey (USFWS 1993). It is estimated that less <br /> than 0.1% of the isto - g populations of L. bradshawii remain (USFWS <br /> 1993). In addi ion, th AaCamas Lake population in Washington is <br /> another site re included in the Recovery Plan. This population is <br /> important bec ue it t the largest known population and is outside the <br /> recognized hi cor ange of the species. <br /> As described in the final rule to list L. bradshawii as endangered (53 <br /> FR 38451; September 30, 1988) and Recovery Plan (USFWS 1993), threats to <br /> the L. bradshawii include: (1) loss of habitat; (2) disease; and (3) <br /> reproductive strategy of the species combined with other stressors. <br /> V. PROBLEMS FACING THE SPECIES <br /> A. The present or threatened destruction, modification. or <br /> curtailment of the species' habitat or range. <br /> Habitat has been lost by succession, changes in hydrology, and urban or <br /> agricultural development. Willamette Valley wet prairies continue to <br /> undergo succession and invasion by trees and shrubs. This succession <br /> was once naturally controlled by widespread flooding, browsing animals, <br /> and fire. Flood control projects in the upper Willamette basin, <br />