''Rhododendron macrophyllum'', the Pacific rhododendron, California rosebay, California rhododendron, coast rhododendron or big leaf rhododendron, is a large-leaved species of '' Rhododendron'' native to the

Pacific Coast Pacific coast may be used to reference any coastline that borders the Pacific Ocean. Geography Americas Countries on the western side of the Americas have a Pacific coast as their western or southwestern border, except for Panama, where the P ...

of North America. It is the state flower of Washington.

Description

It is an

evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, which ...

shrub growing up to tall. The leaves, retained for 2–3 years, are long and broad. The

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechanism ...

s are long, with five lobes on the

corolla Corolla may refer to: *Corolla (botany), the petals of a flower, considered as a unit *Toyota Corolla, an automobile model name * Corolla (headgear), an ancient headdress in the form of a circlet or crown * ''Corolla'' (gastropod), a genus of moll ...

; color is usually pink, although variants exist.

Distribution

The northern limit of its range is somewhat north of the border between

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tota ...

and the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...

British Columbia British Columbia (commonly abbreviated as BC) is the westernmost Provinces and territories of Canada, province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include ...

. It is found as far south as

Monterey Bay Monterey Bay is a bay of the Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica ...

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the ...

. It is widely distributed in the Coast Mountains and Cascade Range. It is less abundant in the coastal mountains of Washington and northern

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

and more common south of the Siuslaw River. It is mostly coastal in distribution but extends its range eastward to locations in the Cascade Mountains in Oregon, Washington and British Columbia.

Habitat

''Rhododendron macrophyllum'', like many rhododendrons, thrives in disturbed habitats such as roadside embankments and recently deforested wildlands. They can also live up in the mountains. It also grows in coastal and montane conifer woods.

History and cultivation

Archibald Menzies found ''R. macrophyllum'' growing along with '' Arbutus menziesii'' in May 1792 when he and George Vancouver made their second landfall after leaving

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only ...

, near present-day Port Discovery, Washington.Justice, Clive L. Mr. Menzies' Garden Legacy, Plant Collecting on the Northwest Coast. 2000. Cavendish Books. Seed was sent to England in 1850 by William Lobb. In recent years it has been the main focus of a study group at the Rhododendron Species Foundation in Federal Way, Washington, the Western North American Rhododendron Species Project. The WNARSP is documenting the detailed range and forms of all of the western North American rhododendron species.

Toxicity

The species contains andromedotoxin, which can poison the honey of nearby hives.

References

Other sources

*Davidian, H. H. ''The Rhododendron Species, Volume III – Elepidotes continued''. 1992. Timber Press. . *Cox, Peter A. & Kenneth N.E. ''The Encyclopedia of Rhododendron Species''. 1997. Glendoick Publishing. .

External links

* * {{Taxonbar, from=Q2714739 macrophyllum Flora of the Western United States Garden plants of North America Symbols of Washington (state) Flora without expected TNC conservation status