''Castilleja levisecta'' is a rare species of flowering plant in the family

Orobanchaceae Orobanchaceae, the broomrapes, is a family of mostly parasitic plants of the order Lamiales, with about 90 genera and more than 2000 species. Many of these genera (e.g., ''Pedicularis'', ''Rhinanthus'', ''Striga'') were formerly included in th ...

known by the common name golden paintbrush, or golden Indian paintbrush, listed under the Endangered Species Act in 1997. It is native to

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

and

Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...

, where it is known from eleven remaining populations.USFWS
''Castilleja levisecta'' Five-year Review.
September 27, 2007. It occurred in

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 Idaho. T ...

but all natural occurrences there have been

extirpated Local extinction, also known as extirpation, refers to a species (or other taxon) of plant or animal that ceases to exist in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinct ...

.Center for Plant Conservation
It has been reintroduced to a few areas in Oregon, but it remains to be seen if the plants will survive.The Nature Conservancy
/ref> The plant is a federally listed endangered species of Canada and was listed as threatened in the United States in 1997.COSEWIC
''Castilleja levisecta'' Species Assessment.
November 2007.USFWS
Determination of threatened status for ''Castilleja levisecta'' (Golden Paintbrush).
''Federal Register'' June 11, 1997. On June 30, 2021, the plant was proposed for delisting due to recovery.

Description

''Castilleja levisecta'' (golden paintbrush) was first collected as a modern botanical specimen near Mill Plain, Washington, by Thomas Jefferson Howell in 1880 and was described by Jesse More Greenman in 1898 (Greenman 1898). This is a perennial herb growing in clumps of up to fifteen stems. The leaves are green, containing chlorophyll to undergo

photosynthesis Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored i ...

, but like other ''

Castilleja ''Castilleja'', commonly known as paintbrush, Indian paintbrush, or prairie-fire, is a genus of about 200 species of annual and perennial herbaceous plants native to the west of the Americas from Alaska south to the Andes, northern Asia, and on ...

'' it is a

hemiparasite A parasitic plant is a plant that derives some or all of its nutritional requirements from another living plant. They make up about 1% of angiosperms and are found in almost every biome. All parasitic plants develop a specialized organ called the ...

, capable of tapping the roots of other plants via haustorial connections to obtain nutrients and water. Castilleja levisecta bracts

The

inflorescence An inflorescence is a group or cluster of flowers arranged on a Plant stem, stem that is composed of a main branch or a complicated arrangement of branches. Morphology (biology), Morphologically, it is the modified part of the shoot of sperma ...

contains bright golden yellow bracts with small green flowers tucked between them. It is the only ''Castilleja'' with yellow bracts within its range in the

Pacific Northwest The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Tho ...

. The plant is thought to be

pollinated Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents can be animals such as insects, birds, a ...

bumblebee A bumblebee (or bumble bee, bumble-bee, or humble-bee) is any of over 250 species in the genus ''Bombus'', part of Apidae, one of the bee families. This genus is the only extant group in the tribe Bombini, though a few extinct related genera ...

s, including '' Bombus californicus''. The species is nearly

self-incompatible Self-incompatibility (SI) is a general name for several genetic mechanisms that prevent self-fertilization in sexually reproducing organisms, and thus encourage outcrossing and allogamy. It is contrasted with separation of sexes among individuals ...

, and a plant produces many more seeds when crossed with a less closely related individual, such as a plant from a separate population.Caplow, F
Reintroduction Plan for Golden Paintbrush.
USFWS. 2004. It is known to hybridize and produce viable seed with '' Castilleja hispida'' (harsh paintbrush) in laboratory and experimental grassland settings. Golden paintbrush grows in

prairie Prairies are ecosystems considered part of the temperate grasslands, savannas, and shrublands biome by ecologists, based on similar temperate climates, moderate rainfall, and a composition of grasses, herbs, and shrubs, rather than trees, as the ...

habitat at low

elevation The elevation of a geographic location is its height above or below a fixed reference point, most commonly a reference geoid, a mathematical model of the Earth's sea level as an equipotential gravitational surface (see Geodetic datum § Ver ...

s, generally in soils of gravelly, glacier-carved

sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sa ...

. It often occurs alongside

Idaho fescue ''Festuca idahoensis'' is a species of grass known by the common names Idaho fescue and blue bunchgrass. It is native to western North America, where it is widespread and common. It can be found in many ecosystems, from shady forests to open plai ...

(''Festuca idahoensis'') and

red fescue ''Festuca rubra'' is a species of grass known by the common name red fescue or creeping red fescue. It is widespread across much of the Northern Hemisphere and can tolerate many habitats and climates. It is best adapted to well-drained soils in ...

(''F. rubra''), and it is a member of the

Garry Oak ''Quercus garryana'' is an oak tree species of the Pacific Northwest, with a range stretching from southern California to southwestern British Columbia. It is commonly known as the Oregon white oak or Oregon oak or, in Canada, the Garry oak. ...

ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...

. The remaining Canadian occurrences of the species are on Trial Island and Alpha Islet off of

Vancouver Island Vancouver Island is an island in the northeastern Pacific Ocean and part of the Canadian province of British Columbia. The island is in length, in width at its widest point, and in total area, while are of land. The island is the largest by ...

. There are nine populations in Washington in maritime grasslands and bluffs around the

Puget Sound Puget Sound ( ) is a sound of the Pacific Northwest, an inlet of the Pacific Ocean, and part of the Salish Sea. It is located along the northwestern coast of the U.S. state of Washington. It is a complex estuarine system of interconnected ma ...

. Most of these are on islands, including several on

Whidbey Island Whidbey Island (historical spellings Whidby, Whitbey, or Whitby) is the largest of the islands composing Island County, Washington, in the United States, and the largest island in Washington State. (The other large island is Camano Island, ...

and one on

San Juan Island San Juan Island is the second-largest and most populous of the San Juan Islands in northwestern Washington, United States. It has a land area of 142.59 km2 (55.053 sq mi) and a population of 6,822 as of the 2000 census. Washington State Fe ...

. The species is diploid and has very high genetic diversity for a rare plant, a condition that makes it less likely to experience rapid

extinction Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

. Conservation efforts are underway, especially attempts to increase populations by introducing and reintroducing plants to appropriate habitat, and carefully augmenting extant populations by planting more individuals. The plant has been reintroduced to its former range in the

Willamette Valley The Willamette Valley ( ) is a long valley in Oregon, in the Pacific Northwest region of the United States. The Willamette River flows the entire length of the valley and is surrounded by mountains on three sides: the Cascade Range to the eas ...

in Oregon. These populations will be monitored for the long term, hopefully over twenty years, to assess their health and status.

Ecology and conservation

Golden paintbrush plays an important role in grassland community dynamics and multitrophic interactions. For example, its hemiparasitic reliance on other plant species in its habitat is thought to affect competition and dominance among other plant species in its community. Additionally, its foliage naturally contains defensive compounds called

iridoid glycosides Iridoids are a type of monoterpenoids in the general form of cyclopentanopyran, found in a wide variety of plants and some animals. They are biosynthetically derived from 8-oxogeranial. Iridoids are typically found in plants as glycosides, mo ...

that are sequestered in the tissues of the endangered Taylor's checkerspot butterfly larvae, which have developed a tolerance for these compounds and are able to consume golden paintbrush foliage. These sequestered iridoid glycosides then confer chemical protection against bird predators to the butterfly larvae. Seeds of putative Castilleja levisecta × C

Seeds of putative Castilleja levisecta × C

The grassland habitats in which golden paintbrush grows have traditionally undergone periodic

wildfire A wildfire, forest fire, bushfire, wildland fire or rural fire is an unplanned, uncontrolled and unpredictable fire in an area of combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identi ...

s, and the golden paintbrush appears to thrive in this

fire regime A fire regime is the pattern, frequency, and intensity of the bushfires and wildfires that prevail in an area over long periods of time. It is an integral part of fire ecology, and renewal for certain types of ecosystems. A fire regime describes th ...

, possibly because fires clear out taller vegetation that would otherwise compete with it, or provide it nutrients in the

ash Ash or ashes are the solid remnants of fires. Specifically, ''ash'' refers to all non-aqueous, non- gaseous residues that remain after something burns. In analytical chemistry, to analyse the mineral and metal content of chemical samples, ash ...

. Fire frequency may also have effects on golden paintbrush's defensive phytochemistry. If the paintbrush is fire-adapted, it would experience negative effects from

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 ...

efforts. Other threats to the species include

habitat destruction Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ...

during residential or other development, and encroachment from introduced plant species such as

mouse-ear hawkweed ''Pilosella officinarum'' ( synonym ''Hieracium pilosella''), known as mouse-ear hawkweed, is a yellow-flowered species of flowering plant in the daisy family Asteraceae, native to Europe and northern Asia. It produces single, lemon-coloured infl ...

(''Hieracium pilosella''),

Scotch broom ''Cytisus scoparius'' ( syn. ''Sarothamnus scoparius''), the common broom or Scotch broom, is a deciduous leguminous shrub native to western and central Europe. In Britain and Ireland, the standard name is broom; this name is also used for other ...

(''Cytisus scoparius''), and

oxeye daisy ''Leucanthemum vulgare'', commonly known as the ox-eye daisy, oxeye daisy, dog daisy, marguerite (french: Marguerite commune, "common marguerite") and other common names, is a widespread flowering plant native to Europe and the temperate regions ...

(''Leucanthemum vulgare''). Plants experience

herbivory A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...

by wild animals, trampling by

hikers Hiking is a long, vigorous walk, usually on trails or footpaths in the countryside. Walking for pleasure developed in Europe during the eighteenth century.AMATO, JOSEPH A. "Mind over Foot: Romantic Walking and Rambling." In ''On Foot: A Hist ...

, and losses when they are picked by wildflower enthusiasts. The hybridization potential between golden and harsh paintbrush has been identified as a threat to the genetic integrity of golden paintbrush, requiring land managers to develop strategies for balancing the ecological needs of these two ''

'' species and endangered insects that rely on them.

References

External links

Cascadia Prairie Oak Partnership technical library items on ''Castilleja levisecta''Photo gallery
{{Authority control levisecta Flora of British Columbia Flora of Washington (state)