Polyploidy in phenotypic space and invasion context: a morphometric study of Centraurea stoebe s.l.
Bibliographic record
Abstract
The taxonomy of the Centaurea stoebe complex is controversial. Diploid and tetraploid plants occur in its native European range, but to date only tetraploids have been recorded from its introduced range in North America. We examined morphological differentiation of C. stoebe using multivariate and univariate approaches to clarify the taxonomic status of the known cytotypes. We measured more than 40 morphological traits on plants originating from 78 populations, grown from seed under uniform glasshouse conditions. The ploidy of almost 300 plants from 2 native and 20 introduced populations from Canada was assessed to test for the absence of diploids from North America. Finally, we explored whether postintroduction processes have resulted in phenotypic changes in introduced plants which may have contributed to the invasion success of C. stoebe. Morphometric analyses showed a clear separation of 2x and 4x plants and thus supported recognition of both cytotypes as separate taxa. Differences in the life cycle, the number of florets, the shape of capitula, and the shape of young rosette leaves were the best discriminant characters. Only minor differences were found between native and introduced tetraploids. All plants from the introduced range except for one hexaploid were found to be tetraploid. Rare diploids from Canada were identified as Centaurea diffusa or Centaurea psamogenna.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".