Ultrastructure and Carbon Isotope Ratios of Leaves in C<sub>4</sub> Species of <i>Rhynchospora</i> (Cyperaceae) That Differ in the Location of Kranz Cells
Bibliographic record
Abstract
The genus Rhynchospora in the Cyperaceae includes both C3 and C4 species. The C4 species shows two distinct Kranz anatomies: the rhynchosporoid and the fimbristyloid–chlorocyperoid intermediate. This study reports the use of herbarium specimens to obtain the leaf ultrastructure in eight Rhynchospora C4 species in relation to their C4 biochemical subtypes, together with carbon isotope ratios. Despite the use of dried materials, electron microscopic observation revealed the structures of chloroplasts and cell walls. In C4 species with the fimbristyloid–chlorocyperoid intermediate anatomy, Kranz cell chloroplasts had reduced grana and convoluted thylakoids, and suberized lamellae occurred in the mestome sheath cell walls. In C4 species with the rhynchosporoid anatomy, the Kranz cell chloroplasts also had reduced grana and convoluted thylakoids but with less convolution; suberized lamellae occurred in the Kranz cell walls. These data show that the Rhynchospora C4 species have ultrastructural features present in the NADP–malic enzyme–type C4 sedges. The Kranz species had δ13C values typical of C4 plants, as expected, and the values did not differ significantly between the two Kranz anatomies. This study demonstrates that dried herbarium specimens can be used for ultrastructural observation of C4 leaves and provide valuable information for understanding of the photosynthetic diversity.
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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".