With little previous research on Astragalus peckii (Fabaceae), a state-listed
Threatened species in Oregon, I investigated three facets of its biology which are
integral to the conservation and management of the species. First, a four-year
demographic study of two large populations revealed increasing population growth at
one site (Chiloquin) and...
The showy biennial to short-lived perennial Oenothera wolfii (Munz) Raven, Dietrich & Stubbe (Wolf’s evening primrose) occurs in only a small number of isolated populations on the southern Oregon and northern California coast. This rare species is currently listed as Threatened in Oregon, and is considered a Species of Concern...
In addition to its longstanding recognition as an influential evolutionary process, interspecific hybridization is increasingly regarded as a potential threat to the genetic integrity and survival of rare plant species, manifested through gamete wasting, increased pest and disease pressures, outbreeding depression, competitive exclusion, and genetic assimilation. Alternatively, hybridization has also...
Populations of an unknown species of Mimulus, herein
described as Mimulus hymenophyllus Meinke, were located
and studied near Horse Creek, a tributary of the Snake
River in eastern Wallowa County, Oregon. The new species
is differentiated from its apparent closest relative,
Mimulus jungermannioides Suksd., by an annual habit, long
petioles,...
The Mimulus washingtonensis complex is a group of morphologically similar
species centered in the Pacific Northwest. All are rare, and most are under
consideration for listing as endangered. Morphometric and pollination data were
used in developing a revised taxonomy for the group. Five species and two varieties
are recognized. Mimulus...
Astragalus oniciformis Barneby is a xerophyte of the sagebrush deserts of central Idaho. It is a narrow endemic of the upper Snake River Plains where it inhabits stabilized, aeolian sand deposits over Quaternary basalt flows. The objective of this study was to determine the levels and distribution of genetic differentiation...
An experimental reintroduction was performed to determine the best method to create new populations of the tuberous species Perideridia erythrorhiza, a rare vascular plant endemic to southern Oregon. Only a handful of sites are currently present, and many of these are subject to other land uses such as urban development...
Rare plant reintroductions that result in additional or more viable wild populations are important conservation tools for maintaining biodiverse ecosystems. Ideally, such projects are best designed as experiments, to improve biological and ecological knowledge of the selected species and monitoring long-term results. Northern wormwood (Artemisia campestris var. wormskioldii: Asteraceae), a...
Pleuropogon oregonus Chase is a rare wetland grass endemic to eastern Oregon. The species is composed of two widely separated populations, one in Lake County and one in Union County. In order to reduce the risk of extinction, the Oregon Department of Agriculture Native Plant Conservation Program initiated several reintroduction...
Plagiobothrys hirtus (Boraginaceae) is a state and federally listed endangered plant found only in Douglas County, Oregon. This vernal pool endemic has historically been threatened by agricultural conversion of seasonal wetlands in the Sutherlin area, and is currently being eradicated as habitat is lost due to the rapid urban development...