''Bidens amplissima'', also known as the Vancouver Island beggarticks, is a

wetland A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially ...

annual

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

in the sunflower family,

Asteraceae Asteraceae () is a large family (biology), family of flowering plants that consists of over 32,000 known species in over 1,900 genera within the Order (biology), order Asterales. The number of species in Asteraceae is rivaled only by the Orchi ...

that is listed as Special Concern in

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

and has a limited global range. More than 85% of known populations occur in southwestern

British Columbia British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...

, with the remainder in northwestern

Washington Washington most commonly refers to: * George Washington (1732–1799), the first president of the United States * Washington (state), a state in the Pacific Northwest of the United States * Washington, D.C., the capital of the United States ** A ...

.Bryant, S. B. (2013). 2013 Surveys for Vancouver Island Beggarticks (''Bidens amplissima'') in the Little Campbell River Watershed. A Rocha Canada Conservation Science Series. A Rocha Canada, Surrey, B.C., Canada. ''Bidens amplissima'' occurs across a remarkable range of environmental conditions, both along the edges of freshwater ponds and under saline conditions in

estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environm ...

.Klinkenberg, B., & Klinkenberg, R. (2001). COSEWIC status report on the Vancouver Island beggarticks ''Bidens amplissima'' in Canada, in COSEWIC assessment and status report on the Vancouver Island beggarticks ''Bidens amplissima'' in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. 1-25 pp. ''Bidens amplissima'' displays a broad range of morphological variation and overlaps in morphological characteristics with two closely related and occurring species, '' B. cernua'' and '' B. tripartita''.Buchanan, J., Currie, C., Stewart, D. (2015). Habitat associations dormancy, and germination of Vancouver Island beggarticks (Bidens amplissima): restoring populations in British Columbia. Prepared for British Columbia Institute of Technology, Burnaby, BC. 62 pp.Ganders, F. R., Klinkenberg, R., & Klinkenberg, B. (2003). Taxonomy in Conservation Biology: The Enigmatic Vancouver Island Beggarticks. Davidsonia vol 14(3), 63-70.

Description

''Bidens amplissima'' resembles small

sunflowers ''Helianthus'' () is a genus comprising around 70 species of annual and perennial flowering plants in the daisy family Asteraceae commonly known as sunflowers. Except for three South American species, the species of ''Helianthus'' are native to ...

, with many small disk florets in the center and 6-11 yellow ray florets around the margin of the head. Stems and

inflorescences In botany, an inflorescence is a group or cluster of flowers arranged on a plant's stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a main axis ( pe ...

are often hairy,

achenes An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and indehiscent (they do not open ...

are wedge-shaped with 2-4 retrorsed barbed awns. Leaves are coarsely toothed along the margin, often widest at the base and becoming narrow toward the tip and the petiole, when present, is often winged-margined. The leaves of ''B. amplissima'' display considerable variation in shape.Vancouver Island Beggarticks Working Group. 2014. Management plan for the Vancouver Island beggarticks (Bidens amplissima) in British Columbia. Prepared for the B.C. Ministry of Environment, Victoria, BC. 24 pp. Most published descriptions of ''B. amplissima'' suggest that plants have at least some three-lobed, or tripartite, leaves. However, un-lobed or two-lobed individuals have often been observed. Authors have noted that individuals of ''B. amplissima'' often lack the tripartite leaves that have generally been used to identify the species.Ganders, F. R., Berbee, M., & Perseyedi, M. 2000. ITS base sequence phylogeny in ''Bidens'' (Asteraceae): Evidence for the continental relatives of Hawaiian and Marquesan ''Bidens''. ''Systematic Botany,'' ''25''(1), 122-133. Many

botanists This is a list of botanists who have Wikipedia articles, in alphabetical order by surname. The List of botanists by author abbreviation is mostly a list of plant taxonomists because an author receives a standard abbreviation only when that aut ...

have misidentified these unlobed individuals as the common species ''B. cernua,'' which is widespread across most of

North America North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...

and

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

. Following this observation, an examination of

herbarium A herbarium (plural: herbaria) is a collection of preserved plant biological specimen, specimens and associated data used for scientific study. The specimens may be whole plants or plant parts; these will usually be in dried form mounted on a sh ...

material was undertaken to investigate the possibility of misidentified specimens. This investigation resulted in the discovery of 5 specimens from WA that were previously named ''B. cernua'' and were later determined to be ''B. amplissima.'' These included historic collections from as far south as

Seattle Seattle ( ) is the most populous city in the U.S. state of Washington and in the Pacific Northwest region of North America. With a population of 780,995 in 2024, it is the 18th-most populous city in the United States. The city is the cou ...

, and more recent collections near Bellingham, WA. Prior to this discovery, ''B. amplissima'' was thought to be

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to southwestern BC.

Distribution and abundance

''Bidens amplissima'' has a limited global range. More than 85% of known populations occur in southwestern British Columbia, with the remainder in northwestern Washington. The number of previously documented populations that are currently extant is uncertain. When populations were last systematically surveyed in 2012, 21 of 59 previously documented populations in British Columbia were confirmed as extirpated. Between 2022 and 2024, 21 extant populations of ''B. amplissima'' were confirmed, including 6 newly discovered populations not previously documented in British Columbia.Pawluk, M.A. (2024) Unpublished observations.

Habitat

''Bidens amplissima'' is a wetland annual occurring across a remarkable range of environmental conditions, both along the edges of freshwater ponds and under saline conditions in

.Ganders, F. R., Klinkenberg, R., & Klinkenberg, B. (2002). British Columbia loses an endemic species: Bidens amplissima (Asteraceae) also occurs in Washington state. Botanical Electronic News (BEN) No. 293. http://www.ou.edu/cas/botany-micro/ben/ben293.html The species is generally limited to a narrow band of habitat around

pond A pond is a small, still, land-based body of water formed by pooling inside a depression (geology), depression, either naturally or artificiality, artificially. A pond is smaller than a lake and there are no official criteria distinguishing ...

lake A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from ...

and

stream A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a strea ...

margins. ''Bidens amplissima'' often occurs in sites where

waterfowl Anseriformes is an order of birds also known as waterfowl that comprises about 180 living species of birds in three families: Anhimidae (three species of screamers), Anseranatidae (the magpie goose), and Anatidae, the largest family, which i ...

are common, and shows a distinct preference for silty alluvial soils.

Taxonomy

''Bidens amplissima'' is often confused with two closely related and o-coccurring species, ''B. cernua'' and ''B. tripartita''. ''Bidens cernua'' has yellow rays, achenes are wedge-shaped with retrorsed barbed awns, and simple unlobed leaves that are often roughly the same width along the entire length and lack a petiole. In contrast, ''B. tripartita'' is characterized by small rayless heads, achenes are wedge-shaped with retrorsed barbed awns, and leaves that are tripartite. However, un-lobed or two-lobed individuals have often been observed.

Mating system

The mating system of ''B. amplissima'' is not well known. However, the species is known to be capable of

self-pollination Self-pollination is a form of pollination in which pollen arrives at the stigma of a flower (in flowering plants) or at the ovule (in gymnosperms) of the same plant. The term cross-pollination is used for the opposite case, where pollen from ...

Conservation status

''Bidens amplissima'' is Federally listed as a species of Special Concern under Canada's Species at Risk Act. Given that most of its geographic range is in southwestern British Columbia, conservation and management within the province is crucial to the longevity of the species.

References

External links

South Coast Conservation Program, Vancouver Island Beggarticks, ''Bidens amplissima''
*''

Angiosperms Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (). The term angiosperm is derived from the Greek words (; 'container, vessel') and (; 'seed'), meaning that the seeds are enclosed within a fruit. T ...

'' *''

Bidens ''Bidens'' is a genus of flowering plants in the aster family, Asteraceae.''Bidens''.
...

'' *'' Bidens cernua'' *'' Bidens tripartita'' *

Pacific northwest The Pacific Northwest (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. Though no official boundary exists, the most common ...

Species at Risk Act The ''Species at Risk Act'' (, SARA) is a piece of Canadian federal legislation which became law in Canada on December 12, 2002. It is designed to meet one of Canada's key commitments under the International Convention on Biological Diversity. T ...

{{Authority control amplissima Flora of British Columbia Plants described in 1901