Floral Structure Research Articles

Revealing Physiological Basis for Floret Opening Difference Between Indica and Japonica Rice: Based on Floral Structure, Transcriptome, and Endogenous Floret Opening Regulator

Background: The differing floret opening times between subsp. indica and subsp. japonica in rice limit the potential for increased hybrid seed production. Objectives: To elucidate the physiological basis underlying the differences in floret opening time between indica and japonica rice. Materials: A comparative analysis involved nine indica and ten japonica rice varieties. Methods: Using paraffin sectioning, transcriptome sequencing, RT-PCR, and endogenous substance quantification, we investigated the structural variations in floral organs, the differences in the initiation timing of floret opening regulatory pathways, and endogenous regulators. Results: The results indicated insignificant differences in lemma thickness, lodicule thickness, lodicule area, and the coupling-lodicule length between indica and japonica rice. However, japonica rice exhibited larger lodicule-lemma gaps and more vascular bundles compared to indica rice. Within the 9:00 a.m. to 10:00 a.m. interval, the expression of OsAOS1 in α-linolenic acid metabolism and OsISA3 in starch and sucrose metabolism notably increased in indica rice, with no significant change in japonica rice. Additionally, the endogenous JA and α-amylase surged more significantly in indica rice than in japonica rice. The increase in soluble carbohydrate in indica rice is greater than in japonica rice, but the difference is not significant. Conclusions: These findings suggest that in the process of the floret opening, the α-linolenic acid metabolism and starch and sucrose metabolism are initiated earlier in indica rice, accompanied by a more pronounced elevation in endogenous JA and α-amylase. Furthermore, the smaller lodicule-lemma gap in indica rice contributes to earlier floret opening compared to japonica rice.

Yam (Rhizoma Dioscoreae) polysaccharide affects growth performance, immunity, and intestinal microbial community in Bulatmai barbel (LucioBarbus capito)

Polysaccharides from yam (Rhizoma Dioscoreae) can be used as immunopotentiators in aquaculture; however, the protective mechanism of adding them to feed for Bulatmai barbel (LucioBarbus capito) remains unclear. This study aimed to investigate the effects of adding yam polysaccharide (YP) to feed for 8 weeks on the growth performance, antioxidant capacity, gene expression, and intestinal flora of the Bulatmai barbel. The experimental groups were fed a diet including 0.1 %, 0.2 %, 0.4 %, and 0.8 % YP, whereas the diet of the control group contained no added YP, with three replicates per group. The results showed that the addition of YP significantly increased the weight gain rate and specific growth rate of the Bulatmai barbel, which were significantly higher than those of the control group (P < 0.05). The growth effect of the 0.4 % YP (279.77 ± 17.43 g) experimental group was significantly better than that of the other experimental groups, and the feed coefficient (49.35 ± 4.67 g) was significantly lower than that of the control group (P < 0.05). The addition of YP significantly improved immune activity and antioxidant capacity of the liver; HSP70 expression decreased and AKP and SOD expression levels significantly increased in the 0.40 % YP group (P < 0.05). In addition, the relative abundance of intestinal bacteria increased for Fusobacteriota and Firmicutes but decreased in Proteobacteria in the experimental groups compared with the control group. At the genus level, Cetobacterium was the dominant bacterium. With an increase in YP concentration, the relative abundance of Cetobacterium increased, whereas that of Pseudomonas and Phreatobacter decreased. In conclusion, dietary supplementation with 0.4 % YP significantly improved growth performance, antioxidant capacity, and gene expression; and regulated intestinal microbial diversity and floral structure in the Bulatmai barbel.

Floral morphology and pollen placement strategies of bat-pollinated flowers: a comparative analysis within a guild of chiropterophilous plants in a neotropical dry forest

BackgroundSynchronopatric plant species, coexisting and flowering simultaneously, often engage in intense competition for pollen deposition on shared pollinators. This study focuses on the intricate dynamics of chiropterophilous flowers within the neotropical bat-pollination plant guild, specifically investigating the mechanical fit of reproductive structures to pollinating bats at the community level.MethodsUtilizing a diverse guild of bat-pollinated plant species from the Caatinga, the largest dry forest in the Neotropics, our research integrates various key components. Initially, we identified specific contact sites for floral reproductive structures on the bat's body, exploring diverse pollen placement strategies. Subsequent efforts involved characterizing floral traits within the guild and examining their associations with different pollen placement strategies. Precision in the contact of floral reproductive structures was estimated, and findings were integrated by associating pollen placement strategies and precision with the investment in pollen production.ResultsWe found that certain bat body parts, particularly the face and neck, were more frequently contacted by reproductive structures. The three identified categories of pollen placement strategies were evenly distributed among plant species, each linked to specific floral traits. Notably, the absence of oriented herkogamy prevailed in 70% of the species. Morphometric analyses unveiled significant variations in operative distances among species, emphasizing exceptional variability in certain outliers. While precision in pollen transfer was influenced by key factors, surprisingly, investment in pollen production did not differ among plants with distinct pollen placement strategies. Furthermore, it showed no correlation with fundamental accuracy.ConclusionsThe subsequent exploration delves into the intricate associations between distinct floral characteristics and various pollen placement strategies, shaping the complex pollen landscape on bat bodies. This research provides valuable insights into the community-level dynamics of chiropterophilous flowers in the Caatinga Dry Forest, emphasizing the role of different pollen deposition strategies in facilitating the coexistence of multiple plant species within the chiropterophilous guild.

A A new species of Graffenrieda (Melastomataceae) from the northern Andes, Caquetá, Colombia, and a key for the Graffenrieda group with calyptrate flowers

Background and Aims: Graffenrieda is a Neotropical genus with more than 70 species, mainly distributed in the Guiana Shield and the Andes. This work describes a new species of Graffenrieda and provides a key to identify all species with calyptrate flowers in the genus.Methods: The description of this new species was made from collections deposited in the Colombian herbaria JBB and COAH. Measurements of vegetative parts and inflorescence were made from dried material, while floral structures and fruits were measured from fresh material preserved in alcohol. Their conservation status was assessed according to IUCN guidelines. A key for the recognition of all species of the genus with calyptrate flowers, including the new species and Centronia species to be transferred to Graffenrieda is also provided here, for which lists of species in Neotropical countries, collection databases, and literature on both genera were consulted.Key results: Graffenrieda cardenasii sp. nov. is endemic to the southern Cordillera Oriental of Colombia and is characterized by its indumentum of irregular lepidote trichomes on the vegetative parts, leaves with incomplete lateral anisophylly, leafy bracteoles as large as the flower buds, 5-merous flowers, calyptrate calyx and 2-locular ovary. It is categorized as Endangered in view of its endemicity and habitat specificity. A key is provided for 30 species of the genus Graffenrieda that share the character of calyptrate flowers.Conclusions: This species is named in honor of the Colombian botanist Dairon Cárdenas López, a great collector and connoisseur of the Colombian Amazonian flora. It is so far known only from the type localities. The key to the species with calyptrate flowers included in this article allows 43% of the species in the genus Graffenrieda to be recognized, including four Centronia species.

Pollination ecology of Dracula erythrochaete (Orchidaceae): brood-site imitation or food deception?

Abstract Pleurothallidinae is the most diverse Neotropical subtribe in Orchidaceae and is almost exclusively pollinated by insects of the order Diptera. Dracula, a genus of 138 species in the Pleurothallidinae, is known to attract Zygothrica (Drosophilidae) flies, common macrofungi visitors, by imitating fungal volatile compounds and lamellae. Interestingly, Dracula orchids do not appear to offer any rewards to their floral visitors. While brood-site imitation of macrofungi has been suggested as their pollination system, the exact behaviour of flies during their extended visits to the orchid flowers has yet to be confirmed. In this study, we document the pollination mechanism of Dracula erythrochaete. We characterize the floral structures involved in the mechanism using anatomical and morphological evidence. Additionally, through in situ observations and camera recordings, we describe the insect behaviour. We show that flowers of D. erythrochaete share the same group of visitors as nearby macrofungi, including different Zygothrica species, seven of which were determined as effective pollinators. Male and female flies were attracted to the flowers and displayed feeding behaviour. Accordingly, proteins were detected in high concentrations on the papillae at the base of the movable lip and in papillary trichomes of the sepals, near the column. The concept of brood-site imitation is debated, as no oviposition events were observed and no eggs were found on the flowers. Therefore, a mixed strategy of congregation/brood-site imitation and food reward is proposed for pollination.

Fabrication of a novel microflower BiOCl composite incorporated with rosemary powder for enhanced oxygen vacancies and visible-light photocatalytic efficiency

Incorporating metallic or nonmetallic compounds is a promising method for enhancing the oxygen vacancies (OVs), charge transport, and visible light absorption of a bismuth oxychloride (BiOCl) semiconductor. This research aims to improve the properties of BiOCl by incorporating rosemary powder (RPC). BiOCl photocatalysts with enhanced OVs were synthesized through the addition of 1–4 wt% of RPC using a one-pot solvothermal process. The addition of 3 % RPC resulted in the formation of very small particles on the BiOCl lamellar structures, which were aligned with the (002) plane of carbon quantum dots (CQDs). The uniformly distributed CQDs transformed the BiOCl microstructure from a two-dimensional lamellar structure to a three-dimensional floral structure, leading to an increased surface area and pore volume. The incorporation of RPC enhanced the visible light absorption capacity of BiOCl. The carbon atoms in RPC readily attach to oxygen atoms in the Bi-O bond, disrupting the Bi-O lattice bond and forming OVs. The addition of RPC contributed to a higher number of OVs, which impacted both the energy difference between the valence and conduction bands and their locations. This resulted in better charge transfer and enhanced active species formation. The 3 %-RPC-BOC photocatalyst had the highest efficiency, achieving a 98 % degradation of rhodamine B (RhB) and a 45 % removal of organic carbon within 48 min under visible light. This composite also had excellent stability and reusability, as its crystal structure remained unaltered even after conducting 7 cycles. The primary active species of 3 %-RPC-BOC system is the superoxide radical (·O2-), while the hydroxyl radical (·OH) and hole (h+) operate as minor active species. Additionally, the 3 %-RPC-BOC achieved a high tetracycline (TC) removal rate of 82.1 %, which is 2.21 times higher than that of pure BiOCl.

Floral resource availability declines and florivory increases along an elevation gradient in a highly biodiverse community.

Flower-visitor interactions comprise a continuum of behaviors, from mutualistic partners to antagonistic visitors. Despite being relatively frequent in natural communities, florivory remains unexplored, especially when comprising abiotic factors, spatio-temporal variations and global environmental changes. Here, we addressed the variation of florivory driven by changes in elevation and temporal flower availability. We expect decreased floral resources as elevation increases -due to environmental constraints- which may affect plant-florivore interactions. Yet, if floral resources decrease but florivores remain constant, then we may expect an increase in florivory with increasing elevation in the community. The flowering phenology of plant individuals was recorded in the Neotropical campo rupestre vegetation, in southeastern Brazil. Damages by florivores were recorded in plots at elevations ranging from 823 to 1411 m using two response variables as a proxy for florivory: the proportion of attacked flowers per plant and the proportion of petal removal on single flowers. Flower attack increased with elevation and damages were intensified in species with longer flowering periods. Conversely, longer flowering periods resulted in higher levels of petal removal when decreasing elevation. The temporal availability of flowers affected florivory, with the proportion of attacked flowers being more intense when there are less flowered individuals in the community. Petal removal on single flowers was intensified in plots with a larger number of individuals flowering, and with more species co-flowering. This study brings one of the broadest records of a commonly neglected interaction of insects feeding on floral structures, quantifying the combined effect of floral display and availability along an elevation gradient in a highly biodiverse mountaintop community. These findings contribute to filling in the gap in the understanding of florivory dynamics, focusing on a tropical mountaintop scenario facing imminent environmental changes and excessive natural resource exploitation.

Trades-offs between pollinator attraction and florivore defense maximize reproductive success in the self-incompatible Rivea ornata (Convolvulaceae)

BackgroundRivea ornata, a rare species from the morning glory family, exhibits uncommon characteristics compared to other typical morning glories, including nocturnal flowers that fit the classic moth pollination syndrome. However, the accuracy of its predicted pollination syndrome and its mating system have never been assessed. Additionally, R. ornata flowers attract not only pollinators but also florivores, potentially reducing plant reproductive success. Therefore, this study examined two populations of R. ornata in Thailand and assessed traits related to pollinator attraction and reward, determined its mating system, identified floral visitors and effective pollinators, and investigated the effect of florivory on reproductive success.ResultsRivea ornata is highly fertile but self-incompatible and an obligate outcrosser, rendering it highly dependent on pollinators. Lepidopterans, particularly nocturnal hawk moths, were found to account for a significant proportion of all visits and were the sole effective pollinators of this plant species, in correspondence with its predicted pollination syndrome. Surprisingly, florivory did not significantly reduce reproductive success. This phenomenon may be explained by the strategies employed by R. ornata, which align with the optimal defense hypothesis and functional trade-offs. Specifically, R. ornata appears to invest resources in defending key floral structures while, simultaneously, guard ants are conspicuously absent from flowers, resulting in some florivore damage to non-vital floral organs but ensuring that pollinators are not deterred by ants and thus maintaining high pollinator visitation rates.ConclusionsOur findings indicate that reproduction-related traits in R. ornata, including those involved in pollinator attraction and reward and florivore defense, are highly effective and work in concert to maximize plant reproductive success. Therefore, a main risk that R. ornata faces is the decline or disappearance of hawk moths and other lepidopterans given its extreme specialization and high dependence on pollinators, and conservation efforts should include habitat protection for both R. ornata and its pollinators.

Floral structure and nectary anatomy of Bertholletia excelsa (Lecythidaceae)

ABSTRACT The floral nectary of Bertholletia excelsa was studied through permanent, histological cross-sections. The flower showed two rings of androecial vascular bundles, the inner for the fertile stamens and the outer for the androecial hood. The androecial hood, originating from the abaxial side of the androecium, is a well-developed, curved, and highly unilateral structure that covers the fertile stamens and stigma. At the apex and on the inner surface of this structure, several finger-like appendages. Histological cross-sections of the androecial hood, from the distal part towards the centre of the flower, reveal that the secretory parenchyma originates in the medium of the inner-distal part of the hood. The secretory tissue is surrounded by vascular bundles that more distally supply the finger-like appendages of the androecial hood. The nectariferous parenchyma lacks internal vascular bundles and consists of small cells, starch-rich, with large vacuoles and a prominent nucleus. The nectariferous epidermis is striated. No stomata or glandular hairs were observed associated with the nectariferous epidermis. The nectary is located within the distal part of the androecial hood and can be classified as a structured, non-vascularized, androecial type. This specialization in the location of the nectar secreting tissue is linked with a complex pollination mechanism, allowing access to the reward only for large bees with long proboscis.

Nature’s Precision: The Intricate Pollen Dispersal Mechanisms of Papilionaceous Crops

Pollination, a fascinating natural process, is crucial for the reproduction of flowering plants. It involves the transfer of pollen from the male reproductive part to the female reproductive part, enabling successful fertilization. Papilionaceous crops, belonging to the Fabaceae family, exhibit highly specialized pollen dispersal mechanisms that ensure effective pollination and genetic diversity. These mechanisms involve intricate interactions between floral structures and pollinators, primarily bees. By integrating findings from various studies, this review provides a comprehensive understanding of the intricate pollen dispersal mechanisms in papilionaceous crops such as piston/pump mechanism, explosive type mechanism, brush type mechanism and valvular mechanism. It also provides information about the role of different floral parts in pollen dispersal among the flowers. This review will be helpful in gaining insights about pollen dispersal mechanism and it contribution in improving crop yields and breeding programs.

What's that smell? The putrid scent of Rafflesia consueloae, its origin and developmental regulation

We report the floral scent composition of the endophytic holoparasite Rafflesia consueloae for the first time. Using a non-destructive in situ method that we developed, we identified 13 volatile compounds present in the scent of R. consuelaoe. Among the compounds detected were several benzenoids, organosilicons, an oligosulfide, a monoterpenoid, and a fatty acid-derived compound. Comparing the scent profiles of different reproductive stages, we found that all stages produced a similar set of volatiles, except for the flowers in bloom. The sulfur-containing dimethyl disulfide (DMDS), which is mainly responsible for the rotten smell of the flower, was only detected in the scent of full-bloom flowers indicating that its synthesis only takes place when the aperture is fully open and the flies are able to access the sex organs. Moreover, an analysis of the scent components of different floral parts from full-bloom flowers revealed that the different floral structures had varying scent profiles. The diaphragm and chamber floor produced the most volatiles. Notably, DMDS was only detected from the diaphragm and the central disk. Emission of putrid-smelling volatiles in these tissues may lure the flies into entering the floral chamber where the reproductive structures are located, thus increasing pollination success. Overall, this pioneering study of the R. consueloae floral scent composition provides valuable insights into the pollination mechanisms of the enigmatic Rafflesia genus and parasitic floral ecology in general.

Biometric variability of inflorescence and flower traits among ex situ accessions of the neotropical oilseed palm Acrocomia Mart.

The oilseed palm genus Acrocomia is suitable for sustainable oil production in South America. The high phenotypic diversity of wild populations poses a challenge for the delimitation of the genus. Comparing the inflorescence architecture, a first-order panicle, and staminate and pistillate flower traits could be a valuable tool in resolving the taxonomic disarray. Thus, this study aims to characterize the differences in the inflorescence architecture and floral structures of three common and economically significant Acrocomia species: A. aculeata, A. totai, and A. intumescens. Biometric traits of the inflorescence architecture and floral structures of various Acrocomia accessions in an ex situ germplasm collection in Brazil were assessed. The unweighted pair group method with arithmetic mean (UPGMA) cluster analysis based on the Gower distance was used to measure dissimilarities between the individual plants of the accessions. To our best knowledge, this study provides the first evidence of the presence of second-order rachillae in the genus Acrocomia. Evaluated traits showed a high level of variation within and between accessions, emphasizing the phenotypic diversity of the genus. The accessions of A. totai were distinguishable from those of the other two species by their inflorescence architecture and flower traits. The dissimilarities between A. aculeata and A. intumescens were not sufficient to differentiate both. In conclusion, the quantitative assessment of inflorescence and floral traits is a valuable tool for taxonomic resolution of the genus.

Variations of floral temperature in changing weather conditions.

Floral temperature is a flower characteristic that has the potential to impact the fitness of flowering plants and their pollinators. Likewise, the presence of floral temperature patterns, areas of contrasting temperature across the flower, can have similar impacts on the fitness of both mutualists. It is currently poorly understood how floral temperature changes under the influence of different weather conditions, and how floral traits may moderate these changes. The way that floral temperature changes with weather conditions will impact how stable floral temperatures are over time and their utility to plants and pollinators. The stability of floral temperature cues is likely to facilitate effective plant-pollinator interactions and play a role in the plant's reproductive success. We use thermal imaging to monitor how floral temperatures and temperature patterns of four plant species (Cistus 'snow fire' and 'snow white', Coreopsis verticillata and Geranium psilostemon) change with several weather variables (illumination, temperature; windspeed; cloud cover; humidity and pressure) during times that pollinators are active. All weather variables influenced floral temperature in one or more species. The directionality of these relationships was similar across species. In all species, light conditions (illumination) had the greatest influence on floral temperatures overall. Floral temperature and the extent to which flowers showed contrasting temperature patterns were influenced predominantly by light conditions. However, several weather variables had additional, lesser, influences. Furthermore, differences in floral traits, pigmentation and structure, likely resulted in differences in temperature responses to given conditions between species and different parts of the same flower. However, floral temperatures and contrasting temperature patterns that are sufficiently elevated for detection by pollinators were maintained across most conditions if flowers received moderate illumination. This suggests the presence of elevated floral temperature and contrasting temperature patterns are fairly constant and may have potential to influence plant-pollinator interactions across weather conditions.

Selection of Stable Reference Genes for QRT-PCR in Tree Peony 'Doulv' and Functional Analysis of PsCUC3.

(1) Background: Tree peonies display extensive cultivar diversity due to widespread hybridization, resulting in a complex genetic architecture. This complexity complicates the selection of universal reference genes across different cultivars for qRT-PCR analyses. Paeonia suffruticosa 'Doulv', notable for its unique green blooms in China, exhibits chlorosis post-flowering and features petaloid stamens and pistils. (2) Methods: Based on published literature and RNA-seq data from 'Doulv', nine candidate reference genes-ACT (Actin), TUB (β-Tubulin), UBC (Ubiquitin Conjugating Enzyme), UBQ (Ubiquitin), UPL (Ubiquitin Protein Ligase), PP2A (Protein Phosphatase 2A), PP2C (Protein Phosphatase 2C), MBF1A (Multiprotein Bridging Factor 1A), and GAPDH (Glyceraldehyde-3-Phosphate Dehydrogenase)-were selected. Their expression stability was assessed across various tissues and developmental stages of 'Doulv' flowers using qRT-PCR, with evaluations conducted via GeNorm_v3.5, NormFinder_v20, and BestKeeper_v1.0. Gene cloning and expression analyses of PsCUC3, including its subcellular localization, were performed. (3) Results: GAPDH and ACT were identified as the most stable reference genes in petaloid stamens across various developmental stages of 'Doulv', whereas UBC and MBF1A were optimal across different tissues. Notably, specific conserved amino acids in PsCUC3 from 'Doulv' diverged from those in NAM/CUC3 proteins of other species, impacting its protein structure. PsCUC3 expression analysis revealed no correlation with chlorophyll content in petaloid stamens but an association with petaloid organ development. Furthermore, PsCUC3 was predominantly localized in the nucleus. (4) Conclusions: This study comprehensively evaluated suitable reference genes using GeNorm_v3.5, NormFinder_v20, and BestKeeper_v1.0 software, establishing a robust qRT-PCR detection system for 'Doulv' peony. These results provide a solid experimental foundation for further research on 'Doulv' peony. Building on this experimental foundation, the functional analysis of the PsCUC3 gene was conducted. The findings suggest a potential association between the PsCUC3 gene and floral morphology alterations in 'Doulv', identifying PsCUC3 as crucial for understanding the molecular mechanisms influencing floral structure in tree peonies.

The seed morphospace, a new contribution towards the multidimensional study of angiosperm sexual reproductive biology.

The evolutionary success of flowering plants is associated with the vast diversity of their reproductive structures. Despite recent progress in understanding angiosperm-wide trends of floral structure and evolution, a synthetic view of the diversity in seed form and function across angiosperms is lacking. Here we present a roadmap to synthesise the diversity of seed forms in extant angiosperms, relying on the morphospace concept, i.e. a mathematical representation which relates multiple traits and describes the realised morphologies. We provide recommendations on how to broaden the range of measurable traits beyond mass, by using key morphological traits representative of the embryo, endosperm, and seed coat but also fruit attributes (e.g., dehiscence, fleshiness). These key traits were used to construct and analyse a morphospace to detect evolutionary trends and gain insight into how morphological traits relate to seed functions. Finally, we outline challenges and future research directions, combining the morphospace with macroevolutionary comparative methods to underline the drivers that gave rise to the diversity of observed seed forms. We conclude that this multidimensional approach has the potential, although still untapped, to improve our understanding of covariation among reproductive traits, and further elucidate angiosperm reproductive biology as a whole.

Untangling the Taxonomy of Rorida (Cleomaceae) in Iran

This work presents the first comprehensive revision of Iranian Rorida J. F. Gmel. based on extensive field surveys, herbarium visits, literature review, and micromorphological investigations. Our taxonomic assessment shows that these taxa can be delimited from each other by a combination of habit, leaf size and morphology, indumentum type, details of floral structure, fruit shape and size, and seed color. We recognize five species of Rorida for the flora of Iran and propose two new combinations: R. dolichostyla (Jafri) Khorasani &amp; Naqinezhad and R. fimbriata (Vicary) Khorasani &amp; Naqinezhad. Moreover, two new records of Rorida for the flora are reported, R. tomentella (Popov) Thulin &amp; Roalson and R. droserifolia (Forssk.) Thulin &amp; Roalson. An identification key to all Iranian Rorida, nomenclature, and comprehensive descriptions are provided for each species, along with notes on taxonomy and ecology (phytogeography, habitat, and conservation status), illustrations, and distribution maps.

'Organ'ising Floral Organ Development.

Flowers are plant structures characteristic of the phylum Angiosperms composed of organs thought to have emerged from homologous structures to leaves in order to specialize in a distinctive function: reproduction. Symmetric shapes, colours, and scents all play important functional roles in flower biology. The evolution of flower symmetry and the morphology of individual flower parts (sepals, petals, stamens, and carpels) has significantly contributed to the diversity of reproductive strategies across flowering plant species. This diversity facilitates attractiveness for pollination, protection of gametes, efficient fertilization, and seed production. Symmetry, the establishment of body axes, and fate determination are tightly linked. The complex genetic networks underlying the establishment of organ, tissue, and cellular identity, as well as the growth regulators acting across the body axes, are steadily being elucidated in the field. In this review, we summarise the wealth of research already at our fingertips to begin weaving together how separate processes involved in specifying organ identity within the flower may interact, providing a functional perspective on how identity determination and axial regulation may be coordinated to inform symmetrical floral organ structures.

The ontogeny of flowers and inflorescences in the andromonoecious annual Iranian endemic Dicyclophora persica (Apiaceae)

Species of Apiaceae, despite uniform floral structure, show great variation in floral morphs and sexual distribution. In the present study, the ontogeny of the diclinous flowers within the cage‐shaped inflorescences of the andromonoecious Dicyclophora persica Boiss. was studied using scanning electron microscopy (SEM), to determine if they follow the same ontogenetic processes. The development of an interesting, unusual club‐like organ in the center of the umbel was also studied. Our findings show that the floral organs in diclinous flowers follow the same pattern. Petals initiate in a clockwise direction, while stamens form in a helical pattern. The perfect central sessile flower in the umbellet, despite sepal suppression, was synchronized with inner staminate flowers in the initiation of petals, stamens, and carpels. In staminate flowers, two prominent sepals initiate after the inception of the stamens. Ovules only get aborted in the late stages. The club‐like organ initiates from a naked receptacle that has no resemblances to umbellets or flowers. In perfect flowers, the delayed initiation and prolonged spatial constraints are caused by bracts and massive staminate flowers which suppress the sepals and make them sessile. Considering the ovule suppression, staminate flowers may be adapted to prevent the perfect flowers from being exposed to extreme environmental conditions.

Eugenia (Myrtaceae) from Reserva Natural Vale, Espírito Santo, a center of plant endemism in the Brazilian Atlantic Rainforest

Eugenia includes ca. 1,100 species worldwide and is the richest angiosperm genus of Brazilian flora with a remarkable biodiversity in the Atlantic Rainforest. In Espírito Santo state, the central-north region conserves the biggest forest fragment and is composed by the lowland coastal forests known as Tabuleiro. Considering the scarcity of studies approaching this vegetation and the high diversity of Eugenia species, this work presents a taxonomic treatment of Eugenia species from Reserva Natural Vale. The study area is located at the municipalities of Linhares and Sooretama, in the northern part of the coastal mesoregion of the state. For the taxonomic treatment, fieldwork was carried out between August 2015 and March 2019 and herbarium collections of BHCB, CVRD, CEPEC, ESA, HRCB, HPL, HUFSJ, ICN, K, MBM, MBML, RB, RBR, SORO, SP, SPF, SPSF, UB, UEC, and VIES were consulted, as well as images of nomenclatural types available online. This work points out the occurrence of 48 species of Eugenia within Reserva Natural Vale, encompassing 48% of the Eugenia species recorded in the Espírito Santo state. Six of them are presented as new occurrences for the reserve (Eugenia arenaria, E. disperma, E. florida, E. handroi, E. pachnantha and E. schottiana); two (E. pachnantha and E. schottiana) are first recorded for the state; E. adenophylla and E. infuscata are described as new. Eugenia adenophylla, E. atlantica, Eugenia cataphyllea, E. flavicarpa, E. hispidiflora, E. ochracea, E. penduliflora, and E. soteriana are endemic to Tabuleiro coastal forest, and E. handroi is the only record for Espírito Santo state. The most useful characters to distinguish the species are hair colours, especially in the floral structures, midvein on the adaxial surface of leaf blades, inflorescence type, connation and persistence of bracteoles, and the presence or absence of indumentum on the flowers’ hypanthia. Furthermore, morphological descriptions, distribution and phenology data, taxonomic comments, species illustrations, and an identification key for the species in the reserve are presented.

Asclepiadaceae of Maharashtra

Family Asclepiadaceae is represented by 250 genera and ca 3000 species mainly distributed in tropical and subtropical regions of the world. It is represented by 43 genera and ca 243 species in India, of which, 31 genera, 82 species, 2 subspecies and 7 varieties are known from the State of Maharashtra. The family is well known for endemism, most elaborate complicated flower of all the dicots and contrivances for pollination. Most of the members of the family are restricted in distribution and many of them fall under some IUCN categories of rare plants. Many of the species are not available for taxonomic studies due to rarity of plant materials. Similarly fleshy nature of flowers makes it difficult to study floral structure in dried herbarium specimens. During last decade, deliberate attempts were made to collect asclepiads of Maharashtra and study their characters in fresh and prickled liquid preserved materials. During 10 years intensive survey of asclepiads of Maharashtra, about 63 species of the total 82 species reported for the State have been collected, documented, photographed, studied and reported in the present paper. The genus Ceropegia alone accounts for 24 species and 2 varieties for the state. Photographs of asclepiad flowers are found to be of paramount value in easy identifications than their descriptions. The paper gives an account of Asclepiads of Maharashtra, their distribution and present field status.