''Ivesia rhypara'' is a species of flowering plant in the

rose family Rosaceae (), the rose family, is a medium-sized family of flowering plants that includes 4,828 known species in 91 genera. The name is derived from the type genus ''Rosa''. Among the most species-rich genera are ''Alchemilla'' (270), ''Sorbus' ...

known by the common name grimy mousetail, or grimy ivesia. It is native to

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

and

Nevada Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...

in the United States.''Ivesia rhypara''.
The Nature Conservancy. This perennial herb grows from woody roots and a branching

caudex A caudex (plural: caudices) of a plant is a stem, but the term is also used to mean a rootstock and particularly a basal stem structure from which new growth arises.pages 456 and 695 In the strict sense of the term, meaning a stem, "caudex" is m ...

.''Ivesia rhypara''.
Nevada Natural Heritage Program. It has hairy, overlapping, compound basal leaves and stems up to 15 centimeters long. At the ends of the stems are clustered white or pale yellow flowers. Blooming occurs in May through October.''Ivesia rhypara''.
Oregon Department of Agriculture. There are two

varieties Variety may refer to: Arts and entertainment Entertainment formats * Variety (radio) * Variety show, in theater and television Films * ''Variety'' (1925 film), a German silent film directed by Ewald Andre Dupont * ''Variety'' (1935 film), ...

of this plant. The var. ''rhypara'' grows on barren

tuff Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock cont ...

and var. ''shellyi'' grows in rock cracks and crevices on

pumice Pumice (), called pumicite in its powdered or dust form, is a volcanic rock that consists of highly vesicular rough-textured volcanic glass, which may or may not contain crystals. It is typically light-colored. Scoria is another vesicular vol ...

and tuff. When the plants grow in rock fissures they sometimes appear to be lined up in rows.''Ivesia rhypara'' var. ''rhypara''.
Center for Plant Conservation. Associated plants include ''

Purshia tridentata ''Purshia tridentata'', with the common name bitterbrush, is a shrub in the genus '' Purshia'' of the family Rosaceae. It is native to mountainous areas of western North America. Common names include antelope bitterbrush, antelope bush, buc ...

'', '' Poa sandbergii'', '' Gilia congesta'', '' Sitanion hystrix'', '' Scutellaria nana'', and ''

Eriophyllum lanatum ''Eriophyllum lanatum'', with the common names common woolly sunflower, Oregon sunshine and golden yarrow, is a common, widespread, North American plant in the family Asteraceae.Sierra Nevada Wildflowers, Karen Wiese, 2nd Ed. 2013, p. 116 Descri ...

''. Threats to this species, particularly var. ''rhypara'', include

gold mining Gold mining is the extraction of gold resources by mining. Historically, mining gold from alluvial deposits used manual separation processes, such as gold panning. However, with the expansion of gold mining to ores that are not on the surface ...

, as the habitat contains gold deposits. Other threats include cattle,

off-road vehicle An off-road vehicle, sometimes referred to as an overland or adventure vehicle, is considered to be any type of vehicle which is capable of driving on and off paved or gravel surface. It is generally characterized by having large tires with dee ...

fire suppression Wildfire suppression is a range of firefighting tactics used to suppress wildfires. Firefighting efforts in wild land areas require different techniques, equipment, and training from the more familiar structure fire fighting found in populated a ...

, and loss of pollinating insects. The plant gets the name ''rhypara'' ("grimy" in

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

) both from its dusty appearance and from its discoverer, James W. Grimes.

References

{{taxonbar , from=Q6098823 rhypara Flora of Nevada Flora of Oregon Plants described in 1977