Herkogamy in the Plains Pricklypear Cactus Opuntia polyacantha Haw. (Cactaceae: Opuntioideae)
Bibliographic record
Abstract
The spatial separation of anthers and stigmas, also known as herkogamy, is a widespread reproductive strategy in flowering plants. Herkogamy has evolved alongside, or in lieu of, self-incompatibility systems, and functions to limit the rate of self-pollination and autogamy. The prevalence of herkogamy in the cactus family (Cactaceae) is a matter of debate, with no known examples in the subfamily Opuntioideae. In this study, I investigated whether the plains pricklypear cactus Opuntia polyacantha, a member of this subfamily, exhibits herkogamy, and whether it is part of a previously described syndrome. I collected data for 23 floral morphometric traits from 142 hermaphroditic flowers, sampled near Saskatoon, Saskatchewan. I quantified herkogamy in two ways: as a conventional, unidimensional variable (basal herkogamy) and as a novel, two-dimensional variable (triangular herkogamy). Secondary data were collected to document pollen morphology, self-pollination rates, ploidy levels and floral visitor diversity and behaviours. Morphometric analyses showed that triangular herkogamy is more representative than basal herkogamy in O. polyacantha, revealing a continuously variable herkogamous syndrome. Regressions, ANOVAs and principal component analysis revealed few trends between herkogamy and the 23 morphometric traits, demonstrating that the syndrome lacks distinctive floral morphs. The secondary data concurred with the literature, showing uniform pollen morphology, moderate rates of self-incompatibility, variable ploidy levels, and typical floral visitor assemblages. I conclude that O. polyacantha exhibits an unordered, non-categorical form of herkogamy, which has not previously been described, and that a two-dimensional quantification can enhance the study of this floral syndrome in other cacti.
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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 | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| 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".