Dorstenia coenanthia are distinctive pseudanthial inflorescences within Moraceae, yet their internal organization and structural integration remain incompletely understood, in part because two-dimensional approaches cannot capture their complex three-dimensional structure. Here, we provide an exploratory three-dimensional anatomical characterization of the pistillate coenanthium of Dorstenia vitifolia using X-ray micro–computed tomography (µCT) combined with conventional anatomical analyses, providing a non-destructive, spatially explicit framework for interpreting vascular patterning and floral deployment within the receptacle. Our results reveal that the coenanthium is organized as a highly conate and structurally integrated reproductive unit. This integration is expressed by a dense, reticulate network of fine-caliber vascular bundles that permeates the entire receptacle, forming a shared vascular scaffold rather than discrete floral traces. In contrast, larger-caliber vascular bundles retain a bifurcating organization consistent with classical hypotheses proposing that this inflorescence derives from condensed branched cymose systems, although this pattern may also reflect the developmental organization of the coenanthium. Descriptive comparison of the two reconstructed coenanthia showed that the larger specimen had greater vascular investment, a higher number of pistils, and fewer empty alveoli than the smaller specimen. Finally, the occurrence of pistils with inward-curved styles alongside enlarged ovaries may reflect post-pollination changes, although pollination-independent fruit development remains a possibility. These findings provide new insights into the three-dimensional organization and vascular architecture of the pistillate coenanthium in D. vitifolia, establish a structural framework for future studies on the development, evolution, and reproductive biology of Dorstenia, and underscore the value of µCT-based approaches for investigating highly integrated pseudanthial systems.
Galls are structures resulting from the interaction between inducing organisms, such as insects, and plant tissues, representing a highly specialized form of parasitism. These structures constitute unique microenvironments with morphological, anatomical, and biochemical changes that are generally beneficial to the gall-inducing organism. The present study aimed to analyze the morphological, anatomical, and histochemical aspects of leaf galls of Erythroxylum daphnites (Erythroxylaceae). Collections were carried out in the municipality of Jataí, Goiás, Brazil, in a fragment of semideciduous seasonal forest. Mature galls were analyzed morphologically using a stereomicroscope and photographed. For anatomical analysis, leaf and gall fragments were fixed, embedded in resin, sectioned, stained, and observed under a light microscope. For histochemistry, tests were applied to hand-cut sections to detect starch, proteins, lipids, phenolics, and alkaloids. The analyzed galls were fusiform, occurred on the adaxial surface of the midrib, and were covered by a dense reddish indumentum composed of non-glandular, uniseriate, multicellular trichomes. Internally, a parenchymatic cortex was observed, with smaller and compact cells near the larval chamber, which contains a single insect belonging to the order Diptera (Cecidomyiidae). Histochemical tests revealed the presence of starch throughout the cortex, indicating a storage function; proteins in the nutritive tissue and vascular bundles, indicating a feeding function for the inducer; and wide labeling of phenolics and alkaloids, especially in the trichomes and near the larval chamber, suggesting a role in chemical defense. The results demonstrate that E. daphnites galls exhibit a highly modified structure, especially with overexpression of newly induced non-glandular trichomes containing secondary metabolites, highlighting the gall inducer’s capacity for tissue manipulation.
Climate change-intensified drought has jeopardized the survival of forest species across the world's forests through hydraulic failure and reduced CO₂ uptake, with stronger effects in dry forests. However, few studies have tested the coordination of hydraulic and CO2 assimilation rate traits under drought conditions in a seasonally dry forest. For six tree species in the Caatinga dry forest, we hypothesized that (1) traits related to hydraulic efficiency through the xylem, such as the potential hydraulic conductivity (Kp), and traits related to photosynthetic rates, i.e. net CO2 assimilation rate (A) and theoretical maximum stomatal conductance (gmax), would be positively correlated; and that (2) wood density would be negatively correlated with the species vulnerability index (V). Contrary to our first hypothesis, we found a strong negative correlation between A and Kp (r = -0.93), revealing a coordination between high foliar photosynthetic capacity and a more conservative anatomical water transport system. Wood density showed a negative correlation with V (r = -0.83), corroborating the existence of an inverse relationship between mechanical reinforcement and anatomical hydraulic efficiency. We also observed a positive relationship between sapwood area and gmax, and between vascular element length and V. Our results suggest an inverse relationship between carbon acquisition and anatomical redundancy, showing that species from the Caatinga biome exhibit complex hydraulic and photosynthetic mechanisms that allow them to survive in environments with recurring droughts.
