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Climate change could significantly affect the geographic distribution of plant species. Hedeoma multiflora is a vulnerable medicinal and aromatic herb that distributes in the Pampa, Espinal and Chaco biogeographic provinces in austral South America. This integrated approach combines ecological models and cytogenetic evidence to assess the effects of climate change on this species. Species distribution modelling using the Maxent model was implemented under current climatic conditions and three future climate change scenarios, integrating data from three Global Climate Models. The most suitable areas span 68,557 km², encompassing the Sierras Pampeanas in San Luis and Córdoba provinces, and the Tandilia and Ventania systems in Buenos Aires, Argentina. The primary variables influencing the models include elevation (500 to 2000 m.a.s.l.), annual mean temperature (10 to 17 °C), annual precipitation (500 to 900 mm) and precipitation seasonality (50 to 75%). While the results project an expansion in the potential distribution of the species, heterogeneous patterns of range shifts are predicted across the three mountain systems: expansion in Sierras Pampeanas, march in Ventania and retraction in the Tandilia system. Variations in chromosome numbers within four distinct localities were reported, indicating the presence of polyploidy. This could potentially provide adaptive advantages in response to changing climates. This plant lives in habitats that face human-induced alterations and insufficient area protected coverage, then we propose strategies for both in situ and ex situ conservation of this medicinal species in each area.

The scaling relationships between leaf dry mass (LDM) and surface area (LA) can reflect the efficiency of light harvesting and photosynthesis, as well as the ability of plants to withstand biotic and abiotic stress. However, it remains little unknown whether plants alter the scaling relationships of LDM and LA, as along with leaf mass investment per unit area in common species growing in different habitats with high temperature and contrasting water availability. This study involved measuring LA, LDM, and leaf morphological traits (e.g., leaf thickness, dry mass per unit area, and density) in 14 woody species (10 tree species, 2 shrub species, and 2 liana species) that co-occur in wet-hot (WH) and dry-hot (DH) habitats in southwest China. Our results showed that the scaling exponents (α) of LDM vs. LA were consistently greater than 1.0 (indicating the increase in LA fails to keep pace with increasing LDM) for all 14 common species at both sites, irrespective of their growth forms. Furthermore, species exhibited a higher leaf mass investment per unit area and leaf density at the DH site compared to the WH site. These results suggest that the law of “diminishing returns” applies to the scaling relationships of LDM and LA in common species inhabiting both types of habitats. Additionally, plants at the DH site increased leaf mass and density investments, potentially reflecting an essential adaptation to strong selective pressure experienced by plant species in that habitat. This study provides new insights into the scaling relationships of LDM and LA in contrasting habitats, enriching our understanding of the plant life-history strategies and adaptations in response to climate change.

Climate change impact on species can be heterogeneous depending on their environments, exposure, and intrinsic characteristics. Likewise, global warming may have an uneven effect on lineages, depending on whether phylogenetic conservatism or divergence of ecological niches predominates during clade diversification, imposing a higher risk to species groups from certain regions, habitats and lineages. This study evaluates the impact of future climate change on Menonvillea, a genus with 24 species distributed along the Andes and contiguous regions of the Southern Cone. The impact on the main phylogenetic, ecological and biogeographic groups is evaluated, also analyzing the effect on its richness and phylogenetic diversity. Results show a strongly negative impact on most species of the genus. However, the greatest pressure seems to be recovered for high Andean species, mainly from the southern portion of the Southern Andes (between 34°S–53S°), and mostly included in Menonvillea sect. Cuneata. Richness appears to be more impacted in high Andean regions, and the loss of phylogenetic diversity is greater than expected at random. These results highlight the strong negative impact that climate change can induce on lineages distributed in the Andean-Patagonian region, and that show patterns of phylogenetic niche conservatism.

Pollination biology is anchored in natural history studies, defined broadly as the practice of observing and describing an organism's behaviour, interactions, and association with the environment in detail. Remarkable or unexpected observations of natural phenomena involving organisms are then interpreted in the light of prior knowledge. Valuing a variety of approaches to natural history studies from around the world, this Special Issue (SI) in FLORA brings together 29 articles to celebrate the career of Professor Marlies Sazima, who pioneered and influenced a generation of pollination biologists in Brazil. This collection puts together a mix of different studies, from detailed descriptions of the function of floral traits, pollinator foraging behaviour, and their effects on plant fecundity, to studies that scale up natural history information to untangle complex ecological patterns at the level of populations, communities or entire ecosystems. The SI also includes studies that make use of people's fascination with documenting natural phenomena, by using citizen science data as well as compiling data from the literature to produce comprehensive global reviews. We included studies with broad scopes and approaches on purpose, taking liberty with the definition of natural history, to highlight the fundamental practice of observing actual interactions between plants and pollinators in pollination biology studies, as well as to celebrate the diverse contribution made by Prof. Marlies throughout her career. We hope to continue mirroring her fascination with natural history and foster the next generation of scientists to carry on her legacy.

Cucurbita pepo L. is popularly known as pumpkin or zucchini. Compared to the others of the genus, it presents the greatest genetic variability. Thus, given its nutritional and medicinal benefits, it results in many widely cultivated and economically important specimens. Due to this, differentiation between specimens becomes necessary, mainly pumpkin and zucchini which have different characteristics, however they receive the same scientific nomenclature (C. pepo). It is noteworthy that the anatomical knowledge of the specimens helps with taxonomy. Furthermore, due to the economic value, when it comes to vegetative propagation, the identification of structural aspects is important for the success of propagation, which depends on the regeneration of plant tissues. This study aimed to characterize and differentiate two specimens of C. pepo through morphoanatomy and histochemistry. For anatomical study, usual methods in plant anatomy were used to prepare and analyze, under an optical microscope, semi-permanent slides containing transverse sections of the roots, stems, leaves, and paradermic sections of the leaf blades of C. pepo specimens. Histochemical tests were performed on cross-sections of the specimens' leaf blades to locate chemical compounds. The optical microscopic evaluation enabled the anatomical characterization, revealing distinct characters among the specimens. For example, the zucchini shows crystals in the root. Meanwhile, the pumpkin shows sclerenchymatic pericycle in the stem and secretory ducts in the stem and leaves. Histochemical techniques showed the presence of different compounds, differentiating in the presence of starch in the zucchini and triterpenes and steroids in the pumpkin. Correct characterization provides important information for quality control of the plant drug and taxonomic differentiation of the specimens since diagnostic characters vary.

The subfamily Dialioideae comprises 17 genera and 83 species, having a pantropical distribution. Dialium L., the typical and most diverse genus of the subfamily, contains 34 accepted species, of which five are Neotropical. The other genera of Dialioideae are restricted to specific continents. Noteworthy, five genera are exclusively Neotropical, namely Androcalymma Dwyer, Apuleia Mart., Dicorynia Benth., Martiodendron Gleason, and Poeppigia C.Presl. This article presents a palynological study of 21 taxa belonging to six genera of the subfamily Dialioideae, including the above-mentioned five Neotropical genera and the Neotropical species of Dialium. The aim was to characterize pollen grains and thus provide support for the taxonomic circumscription of the group. Pollen grains were acetolysed, measured, described, and illustrated using light microscopy. Surface details and apertures were examined on unacetolysed pollen grains by scanning electron microscopy. The parameters evaluated were shape, size, aperture type, polarity, and exine ornamentation. The analyzed species have medium-sized pollen grains. Pollen shape ranges from isopolar to subprolate, prolate, oblate-spheroidal, prolate-spheroidal, and perprolate. The polar area is small or large, tricolporate, syncolporate, or parasyncolporate in some species, with short, wide, or narrow colpi, ornamented or slightly ornamented membrane, lalongate or lolongate endoaperture, and rugulate, microreticulate, or striate sexine. The sexine is as thick as, thicker than, or less thick than the nexine. Pollen attributes were successfully used to construct a key to distinguish genera and species. The findings show the importance of pollen morphology in the taxonomy of Dialioideae, allowing identification of taxa.

As species are fundamental units of evolutionary biology research, accurate species delimitation plays a crucial role in current biodiversity management. The Qinghai-Tibet Plateau (QTP) comprises one of the global biodiversity hotspots, and plant speciation and its evolutionary history in this region still need much research. Aconitum pendulum and A. flavum (Ranuculaceae) are mainly distributed in the QTP and its adjacent regions. The two species have extremely similar morphological characteristics, and their evolutionary relationship is still controversial. In this study, we collected 244 individuals in 14 populations from the main distribution areas of the two species. Genome-wide single-nucleotide polymorphisms (SNPs) from genotyping-by-sequencing (GBS) of A. pendulum and A. flavum were obtained to decipher the taxonomic delimitation and explore the evolutionary history. We performed neighbor-joining (NJ), PCA, structure, and niche overlap analyses. None of them support that A. pendulum and A. flavum can be considered as two separate species. In addition, the genetic difference between species is less than that among populations. We propose merging the two species into one. We also found that the genetic difference between the two species was not associated with morphological species or geographic distance. Gene flow and genetic drift may play a crucial role in weakening the correlation between genetic distance and geographical distance. A bottleneck effect occurred in the two species during the last glacial maximum. Based on the Maxent and Stairway Plot results, we inferred that A. pendulum and A. flavum still had large survival ranges during the LGM, similar to other cold-tolerant species. Furthermore, human activity, such as overexploitation causing habitat fragmentation, might be one of the factors that threat to the survival of A. pendulum and A. flavum in the current period.

Anatomical investigations aiming to seek alternative characters for the taxonomy of bamboos are almost exclusively restricted to the leaf blade. Little is known about the anatomical structure of other parts of the leaf, such as the leaf sheath and pseudopetiole. The present paper analyzed the complete structure of foliage leaves, including the foliage leaf blade, foliage leaf sheath, and pseudopetiole of species belonging to the tribes Bambuseae (subtribes Guaduinae, Chusqueinae and Arthrostylidiinae) and Olyreae (subtribe Parianinae) to identify useful characters in the taxonomy of bamboos. We used scanning electron microscopy and light microscopy to describe micromorphological and anatomical features. All species sampled share the following features: foliage leaf blades with uniseriate epidermis; adaxial bulliform cells; mesophyll with arm cells, cavities, and collateral vascular bundles. Intercostal sclerenchyma associated to bulliform cells was observed only in Arthrostylidiinae. Micromorphologically, the shape and distribution of silica bodies, presence, type, and distribution of papillae on the long cells and subsidiary cells, and the presence and distribution of trichomes may be taxonomically informative in different taxonomic levels. We highlight the absence of papillae on the surfaces of foliage leaf blade of Guaduinae since the presence of papillae is considered a putative diagnosis feature supporting the sister relationship of this subtribe with Arthrostylidiinae. We describe the anatomical structure of foliage leaf sheath for the first time for Guaduinae, Chusqueinae and Parianinae. In Guaduinae, we found a unique distribution pattern of silica cells on the abaxial surface of the leaf sheath. Anatomical data about the pseudopetiole structure also were described for the first time in bamboos species; the arrangement of vascular bundles may be taxonomically informative, especially in Guaduinae.

A multi-level study was performed on the vegetative and reproductive organs of Phlomis fruticosa L. (Lamiaceae), cultivated at the G.E. Ghirardi Botanical Garden (Toscolano Maderno, Brescia, Northen Italy). This work is part of the project Ghirardi Botanical Garden, factory of molecules…work in progress, intended to preserve and enhance the plant heritage hosted at the study site. The multidisciplinary research combined four approaches: I) micromorphological, to describe the structures responsible for the productivity of secondary metabolites; II) histochemical, to define the chemical nature of the secretory products by Light Microscopy, Fluorescence Microscopy, and Scanning Electron Microscopy; III) phytochemical, to characterize the Essential Oil obtained from the blooming aerial parts by hydrodistillation with a Clevenger-type apparatus, consequently analysed by Gas Chromatography-Mass Spectrometry; IV) biological, to assess the potential biological activity of the most abundant EO components based on literature data. Overall, P. fruticosa presented non-glandular and glandular trichomes. The former were multicellular stellate or simple uniseriate, the latter capitate belonging to three morphotypes: branched stalked with a one-celled head, simple short-stalked with a one(two)-celled head, simple medium-stalked with a four-celled head. For the first time, the histochemical survey reported digital images showing a predominant terpenes secretion by the branched-stalked and simple medium capitates, while the simple short hairs were responsible for the secretion of mucopolysaccharides and acid polysaccharides. The EO profile revealed 50 compounds and was dominated by sesquiterpene hydrocarbons (51.1 %) and oxygenated sesquiterpenes (33.6 %), with ar-curcumene (24.3 %), caryophyllene oxide (22.5 %) and α-cedrene (12.8 %) as most representative compounds. Finally, based on literature data, antimicrobial, antioxidant, and anti-inflammatory properties were hypothesized.

In the context of Open Science, an original iconographic apparatus was drafted based on these results to make them accessible to the visitors of the G.E. Ghirardi BG, as an opportunity to discover the plant heritage from an unusual perspective.

Fagaceae is an iconic plant family with 1000+ species distributed predominantly in the northern hemisphere. The reproductive ecology of the Fagaceae species is highly complex, and in the past three centuries, understanding the fruit masting strategies, dispersal, pathogen pressure, and storage has enjoyed steady research interest. However, the interrelationship between these factors is surprisingly less explored, undermining how acorns survive the post-dispersal period. The ability of fruits (acorns, nuts) to survive post-dispersal conditions starts during the maturation drying stage. Successful fruit production depends on the maternal environment, with a ‘good fruit production year’ occurring every few years. This phenomenon might out-maneuver predators by providing sufficient numbers to be consumed but still leaving enough for germination. Because most Fagaceae species have desiccation-sensitive (DS) fruits, survival after dispersal is challenging due to frequent dry spells. Fruit size is not phylogenetically conserved within the genus, with the average fruit mass of Castanea being 50 times higher than the desiccation-tolerant genus Fagus. Larger fruit size may be an adaptation in dry areas because prolonged drying continuously desiccates large-sized cotyledons before desiccating embryos. For species adapted to dry environments, synchronizing dispersal with the growing season could be beneficial, but exceptions exist. Many consumers, such as rodents, aid in the dispersal of fruits, but some fruits are killed in the process, especially those predated late. Upon settling on a site, the pericarp protects the embryo to a certain extent; if drying occurs, the cotyledons become the first site of water loss. However, under extreme drying, survival depends on sporadic rainfall, i.e., wet-dry cycle, which aids in maintaining the critical moisture content required by the fruits for survival. Nonetheless, these adaptive mechanisms are challenged by climate change, which affects the maturation, persistence, and seedling establishment of numerous Fagaceae species.