Bidens cernua
species of plant
Bidens cernua is a species of flowering plant in the aster family, Asteraceae. It is commonly called nodding beggarticks or nodding bur-marigold. Bidens cernua is distributed throughout much of Eurasia and North America.
Description
Bidens cernua is an annual species growing roughly 1m tall, with a fibrous root. Stems are rigid and often either simple or beached. Stem leaves are simple, unstalked, and opposite with saw-toothed to almost smooth margins.
It has yellow flowers with 6–8 ray narrowly lance shaped petals around a central disk. The hemispheric heads are solitary at the ends of branches and nod with age.
The achenes are narrowly wedge-shaped and 4-sided, flattened and ribbed. The pappus has 3–4 barbed bristles.
Begin with the source’s own compact description: “Bidens cernua” is species of plant. The dossier treats that line as a proposition to test through Bidens, cernua and species, not as a finished interpretation.
Why this record matters
The phrase “species of plant” supplies a clear boundary for inquiry. It also exposes the unanswered questions: who defined that boundary, when it became stable and which sources sit outside it.
Datasets, specimens, observations and peer-reviewed methods provide the appropriate test for the technical claims summarized here. The source revision retrieved here is dated Aug 21, 2026. The linked authority identifier is Q27501. None of the 0 selected statements returned an explicit reference.
Scientific names, classifications and consensus can change while older terminology persists in catalogues and historical literature. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Check terminology, classification and the date of the cited evidence. Scientific names and technical consensus can change while older records retain historical value.
- Current terminology
- Classification context
- Finding cited technical literature
Primary datasets, specimen catalogues, standards bodies and the most recent peer-reviewed literature.
Three-step research path
- Establish the record: confirm the title “Bidens cernua”, its source revision and the description used here.
- Expand the search: follow Bidens cernua primary sources, Bidens cernua archive and Bidens research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Bidens cernua”?
- Has classification or technical consensus changed since the cited source?
- Is the terminology current, historical or disputed?
Search terms from this dossier
This entry incorporates text from “Bidens cernua” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.