BC Conservation Data Centre: Species Summary
Bidens amplissima
Vancouver Island beggarticks
| Scientific Name: | Bidens amplissima Greene | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| English Name: | Vancouver Island beggarticks | ||||||||||
| Classification / Taxonomy | |||||||||||
| Scientific Name - Concept Reference: | Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR. | ||||||||||
| Classification Level: | Species | ||||||||||
| Taxonomy Comments: | Status report (Klinkenberg and Klinkenberg 2001) provides evidence for delineation of this species contrary to the Illustrated Flora of BC. Douglas, Straley, Meidinger and Pojar (1998), Douglas, Straley and Meidinger (1998), Hitchcock et al. (1955), Douglas et al. (1989) and Greene (1901) describe it as having three-lobed lower or middle leaves. However, Ganders et al. (2000) have indicated that simple-leaved forms frequently occur. When reproductive features (rays and achenes) are used to delineate the species, the range of Bidens amplissima is expanded from Vancouver Island to other parts of BC and WA (and possibly MB and OR). In their work on the flora of the Fraser Valley, Ganders et al. (in prep.) have provided a key that separates the species of Bidens using the reproductive features. | ||||||||||
| Species Group: | Vascular Plant | ||||||||||
| Species Code: | BIDEAMP | ||||||||||
|
|||||||||||
| Conservation Status / Legal Designation | |||||||||||
| Global Status: | G3 (May 2016) | ||||||||||
| Provincial Status: | S3 (Apr 2019) | ||||||||||
| BC List: | Blue | ||||||||||
| Provincial FRPA list: | |||||||||||
| Provincial Wildlife Act: | |||||||||||
| COSEWIC Status: | Special Concern (Nov 2001) | ||||||||||
| SARA Schedule: | 1 - Special Concern (Jun 2003) | ||||||||||
| General Status Canada: | 3 - Sensitive (2010) | ||||||||||
| Ecology & Life History | |||||||||||
| General Description: | |||||||||||
| Technical Description: | |||||||||||
| Subspecies Comments: | None. | ||||||||||
| Identification Comments: | Bidens amplissima is a glabrous to slightly hairy annual wetland species that can have either simple or tri-lobed leaves (and often something in between), and 2-10 large, hemispherical, flower heads sporting 6-11 yellow ray petals. Achenes are trigonous, usually with 4 awns, sometimes of varying length, and broadest below the summit. Summits of the achenes are concave and are not cartilaginous. | ||||||||||
| Similar Species: | This species can be confused with Bidens cernua and Bidens tripartita. B. amplissima is readily separated from B. cernua, which has cartilaginous and concave achene summits (achenes broadest at the summits), globular flower heads, and more numerous petals than B. amplissima. While B. amplissima grows on pond margins, B. cernua is frequently found in deeper standing water. B. amplissima is also readily separated from B. tripartita, which can be very similar in appearance. B. tripartita; however, lacks the ray petals that are typical of B. amplissima. Hybrids do occur, and often populations are a mix of species and hybrids. | ||||||||||
| Provincial Reproduction Comments: | Like most Bidens species, this plant reproduces sexually and produces large numbers of seeds that can latch on to animals and thus become widely dispersed (Klinkenberg and Klinkenberg 2001). | ||||||||||
| Provincial Ecology Comments: | Bidens amplissima is a wetland and shoreline species that is tied to fluctuating water levels that result from annual climatic variation. Like most shoreline species, it is influenced by siltation and light levels (Klinkenberg and Klinkenberg 2001). It often occurs in areas frequented by waterfowl (e.g., preening areas), and is dispersed easily by them (Klinkenberg and Klinkenberg 2001). | ||||||||||
| Habitats: (Type / Subtype / Dependence) |
Other Unique Habitats / Beach / Facultative - occasional use
Other Unique Habitats / Estuary / Facultative - frequent use Other Unique Habitats / Mudflats - Intertidal / Facultative - frequent use Wetland / Marsh / Facultative - frequent use |
||||||||||
| Global Habitat Comments: | Ditches, wet fields, salt marshes. | ||||||||||
| Provincial Habitat Comments: | This species is frequent in wetlands in the lower Fraser Delta and on Vancouver Island. It occupies a variety of wetland habitats including ditches, willow wetlands, old riverbeds, pond margins, streamsides, and tidal or non-tidal river edges (Klinkenberg and Klinkenberg 2001). | ||||||||||
| Provincial Phenology: (1st half of month/ 2nd half of month) |
|||||||||||
| Provincial Phenology Comments: | This is a warm season plant that flowers in late summer. | ||||||||||
| Elevation (m) (min / max): | Provincial: 0 / 100 | ||||||||||
| Known Pests: | |||||||||||
| Pollen Vector: | |||||||||||
| Pollinator: | |||||||||||
| Dispersal: | |||||||||||
| Provincial Inventory | |||||||||||
| Inventory Priority: | |||||||||||
| Ownership of occurrences (Known locations): | Mixed private/government | ||||||||||
| Inventory Need: | Detailed inventory was conducted during the preparation of the COSEWIC status report (Klinkenberg and Klinkenberg 2001) and is not a priority. | ||||||||||
| Inventory Comments: | New populations of this species continue to be found through undirected inventory. The species is frequently dispersed by waterfowl and often occurs in small populations; therefore, it has the potential to be widespread in the region. If inventory is carried out, however, it should target large sustaining populations as they may be key to long-term survival of the species. | ||||||||||
| Economic Attributes | |||||||||||
| Provincial Economic Comments: | Bidens are a common food source for waterfowl and some Bidens are sold as ornamental plants, but no known uses in BC. | ||||||||||
| Distribution | |||||||||||
| Endemic: | N | ||||||||||
| Global Range Comment: | Known from British Columbia and Washington (FNA vol. 21, 2006). | ||||||||||
| Disjunct, more common elsewhere: | N | ||||||||||
| Peripheral, major distribution elsewhere: | N | ||||||||||
| Authors / Contributors | |||||||||||
| Global Information Author: | |||||||||||
| Last Updated: | |||||||||||
| Provincial Information Author: | Brian Klinkenberg | ||||||||||
| Last Updated: | Mar 30, 2005 | ||||||||||
| Last Literature Search: | |||||||||||
| References and Related Literature | |||||||||||
B.C. Ministry of Environment. Recovery Planning in BC. B.C. Minist. Environ. Victoria, BC. |
|||||||||||
Douglas, G.W. 1996. Endemic Vascular Plants of British Columbia and Immediately Adjacent Regions. Can. Field-Nat. 110(3):387-391. |
|||||||||||
Douglas, G.W., D. Meidinger, and J. Penny. 2002. Rare Native Vascular Plants of British Columbia, 2nd ed. B.C. Conserv. Data Centre, Terrestrial Inf. Branch, Victoria. 358pp. |
|||||||||||
Douglas, G.W., G.D. Straley, and D. Meidinger, eds. 1998b. Illustrated Flora of British Columbia, Vol. 1, Gymnosperms and Dicotyledons (Aceraceae through Asteraceae). B.C. Minist. Environ., Lands and Parks, Wildl. Branch, and B.C. Minist. For. Res. Program. 436pp. |
|||||||||||
Flora of North America Editorial Committee (FNA). 2006c. Flora of North America north of Mexico. Vol. 21. Magnoliophyta: Asteridae, part 8: Asteraceae, part 3. Oxford Univ. Press, New York. xxii + 616 pp. |
|||||||||||
Klinkenberg, B., and R. Klinkenberg. 2001. Status Report on Vancouver Island Beggarticks, Bidens amplissima, in Canada. Unpubl. rep. submitted to the Comm. on the Status of Endangered Wildl. in Can. Ottawa. 25pp. |
|||||||||||
Roemer, H., and M. Fairbarns. 2003. Red and Blue Listed Plants of the Somenos Garry Oak Protected Area. Rep. prepared for the Garry Oak Ecosystem Recovery Team. |
|||||||||||
Please visit the website Conservation Status Ranks for definitions of the data fields used in this summary report.
Suggested Citation:
B.C. Conservation Data Centre. Species Summary: Bidens amplissima. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 7, 2026).