Structural diversity of extrafloral nectaries in <i>Chamaecrista</i> sect. <i>Apoucouita</i>
Bibliographic record
Abstract
Section Apoucouita (Chamaecrista (L.) Moench – Caesalpinioideae) is an arboreal group that is most diverse in the Amazon and Brazilian Atlantic forests. These species typically bear petiolar and (or) rachis glands called extrafloral nectaries (EFNs). However, no detailed anatomical studies or histochemical analyses have been conducted to confirm nectar secretion. We aimed at describing the structure of such EFNs, as well as determining the chemical nature of the secretion. Eighteen species (23 taxa) were studied using standard light microscopy techniques. We describe 13 types of EFNs with variable morphology. Such EFNs may be impressed, sessile, or stalked; with concave, flat or truncate, or convex secretory surfaces. Cupuliform EFNs (stalked or not) were the most common type observed and patelliform the least common. Despite the morphological variation, differences in the anatomical structure of the EFNs and the chemical composition of the secretion were not observed. EFNs with concave secretory surfaces appear to be more effective as nectar may become accumulated in the concavity, increasing the volume of available nectar. Our results show that despite the variable morphology of the EFNs, such structures share similarities on the anatomy and composition of the secretion and development of a wound-healing periderm in older EFNs. We also indicate the importance of including the morphological variation observed in the EFNs in species of sect. Apoucouita in future taxonomic evaluations.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| 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) | 0.000 | 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 teacher head, 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".