Angiosperm Diversification Research Articles

Widespread Whole Genome Duplications Contribute to Genome Complexity and Species Diversity in Angiosperms

Gene duplications provide evolutionary potentials for generating novel functions, while polyploidization or whole genome duplication (WGD) doubles the chromosomes initially and results in hundreds to thousands of retained duplicates. WGDs are strongly supported by evidence commonly found in many species-rich lineages of eukaryotes, and thus are considered as a major driving force in species diversification. We performed comparative genomic and phylogenomic analyses of 59 public genomes/transcriptomes and 46 newly sequenced transcriptomes covering major lineages of angiosperms to detect large-scale gene duplication events by surveying tens of thousands of gene family trees. These analyses confirmed most of the previously reported WGDs and provided strong evidence for novel ones in many lineages. The detected WGDs supported a model of exponential gene loss during evolution with an estimated half-life of approximately 21.6 million years, and were correlated with both the emergence of lineages with high degrees of diversification and periods of global climate changes. The new datasets and analyses detected many novel WGDs widely spread during angiosperm evolution, uncovered preferential retention of gene functions in essential cellular metabolisms, and provided clues for the roles of WGD in promoting angiosperm radiation and enhancing their adaptation to environmental changes.

Tracking the Initial Diversification of Asterids: Anatomically Preserved Cornalean Fruits from the Early Coniacian (Late Cretaceous) of Western North America

Premise of research. The initial radiation of core eudicots (>70% angiosperm diversity) occurred during the Late Cretaceous (100.5–66 Ma). While there is strong fossil evidence for this diversification occurring throughout the Cenomanian (100.5–93.9 Ma) and Turonian (93.9–89.8 Ma), there are no unambiguous reports of the largest core eudicot clade, the asterids, from pre-Coniacian deposits (89.8–86.3 Ma). This study provides new insights into the early evolution of asterids by characterizing anatomically preserved fruits from the early Coniacian (∼89 Ma) of North America that represent three new taxa assignable to the earliest-diverging asterid order, Cornales.Methodology. Three fossil fruit types were identified within calcareous concretions from the Upper Cretaceous Eden Main locality on Vancouver Island, British Columbia. Specimens were prepared using the cellulose acetate peel technique.Pivotal results. These fruits have a thick-walled woody endocarp with germination valves, one apically attached seed...

Diversity of Angiosperm Flora of Kuakata National Park, Patuakhali District, Bangladesh

The article mainly highlights the angiosperm diversity of Kuakata National Park (KNP) of Patuakhali district. Angiosperm diversity assessment in the park was conducted in between 2015 and 2016. A total of 265 plant species belonging to 75 families and 204 genera was identified from this National Park. Tree species of the park are represented by 89, shrubs by 45, herbs by 94, climbers by 31 and epiphytes by 6 species. In Magnoliopsida (dicots), Fabaceae is the largest family represented by 14 species, whereas in Liliopsida (monocots), Poaceae is the largest family represented by 13 species. The plant species recorded from the National Park were distributed in different habitats and maximum species were recorded in plantation areas(108) followed by homesteads (61), cultivated land(38), roadsides (35) and mangrove areas (23).The study has reported the presence of medicinal plants, wildlife supporting plants, exotics and invasive plants and rare plants in park. The presence of edible species in the National Park is very rare. The introduction of exotics species into the National Park has been accepted. As the presence of exotics in park, local flora will be faced great challenges in future for their existence. This article also focused conservation values, management concerns and some actions for conservation of angiosperm diversity in the National Park. The present angiosperm diversity assessment in the park is very preliminary and based on this sound conclusion cannot be made yet.
 Asiat. Soc. Bangladesh, Sci. 43(2): 143-159, December 2017

Who is the most stressed? Morphological disparity and mechanical behavior of the feeding apparatus of ceratopsian dinosaurs (Ornithischia, Marginocephalia)

Ceratopsians were herbivorous dinosaurs that dominated many of the terrestrial ecosystems in Asia and North America during the Cretaceous. The bizarre variety of skulls and lower jaw morphologies as well as the inferred ecological abundance of many species in this clade indicate that Ceratopsia was a successful group. Here we analyzed 126 lower jaws from 50 ceratopsian species, using two-dimensional geometric morphometrics and finite element analysis to investigate differences in shape and structural performance of this part of the feeding apparatus across Ceratopsia. Morphological differences in lower jaws across ceratopsian clades are said to originate from feeding adaptation.Our results show that the stress (physical loadings modeled in response to biting) in lower jaws was quite similar between “basal” and “derived” taxa, whereas major differences among clades occur for stress values associated with the coronoid process. The basal ceratopsians Hualianceratops and Yinlong had a highly stressed and primitive lower jaw, indicating that those animals may have fed on relatively soft foliage and fruits. A similar condition was found for basal neoceratopsians and protoceratopsids. Psittacosaurids possessed a well-integrated and compact lower jaw able to withstand high stress, at the cost of having a highly stressed coronoid process. Leptoceratopsids were characterized by the opposite condition. Taxa such as Leptoceratops, Prenoceratops, Zhuchengceratops and Cerasinops appear to have had a comparatively efficient feeding apparatus. Ceratopsidae represents the clade with the most efficient masticatory apparatus within Ceratopsia, even if the horizontal ramus of the lower jaw appears less able to withstand high levels of stress as compared with other ceratopsians. Additionally, we found the dentary and surangular–angular complex co-evolved to generate a masticatory apparatus able to withstand high stress, particularly in Protoceratopsidae and Triceratopsini. The major phenotypic evolutionary rate and morphological changes occurred during the mid- to Late Cretaceous, when intense climate change and angiosperm diversification could have affected the evolution of ecological diversity and feeding biomechanics in Ceratopsia.

Style morphology and pollen tube pathway.

The style morphology and anatomy vary among different species. Three basic types are: open, closed, and semi-closed. Cells involved in the pollen tube pathway in the different types of styles present abundant endoplasmic reticulum, dictyosomes, mitochondria, and ribosomes. These secretory characteristics are related to the secretion where pollen tube grows. This secretion can be represented by the substances either in the canal or in the intercellular matrix or in the cell wall. Most studies suggest that pollen tubes only grow through the secretion of the canal in open styles. However, some species present pollen tubes that penetrate the epithelial cells of the canal, or grow through the middle lamella between these cells and subepithelial cells. In species with a closed style, a pathway is provided by the presence of an extracellular matrix, or by the thickened cell walls of the stylar transmitting tissue. There are reports in some species where pollen tubes can also penetrate the transmitting tissue cells and continue their growth through the cell lumen. In this review, we define subtypes of styles according to the path of the pollen tube. Style types were mapped on an angiosperm phylogenetic tree following the maximum parsimony principle. In line with this, it could be hypothesized that: the open style appeared in the early divergent angiosperms; the closed type of style originated in Asparagales, Poales, and Eudicots; and the semi-closed style appeared in Rosids, Ericales, and Gentianales. The open style seems to have been lost in core Eudicots, with reversions in some Rosids and Asterids.

Evolution, development, and genetics of floral display—form, size, and arrangement

The flower, frequently arranged in clusters known as inflorescences, is one of the most fascinating outcomes through evolution (Endress, 2010). The dimensions of floral diversity in angiosperms are enormous through variations, such as, in floral size, color, shape, scent, and flowering time.

The genetic breakdown of sporophytic self-incompatibility in Tolpis coronopifolia (Asteraceae).

Angiosperm diversity has been shaped by mating system evolution, with the most common transition from outcrossing to self-fertilizing. To investigate the genetic basis of this transition, we performed crosses between two species endemic to the Canary Islands, the self-compatible (SC) species Tolpis coronopifolia and its self-incompatible (SI) relative Tolpis santosii. We scored self-compatibility as self-seed set of recombinant plants within two F2 populations. To map and genetically characterize the breakdown of SI, we built a draft genome sequence of T.coronopifolia, genotyped F2 plants using multiplexed shotgun genotyping (MSG), and located MSG markers to the genome sequence. We identified a single quantitative trait locus (QTL) that explains nearly all variation in self-seed set in both F2 populations. To identify putative causal genetic variants within the QTL, we performed transcriptome sequencing on mature floral tissue from both SI and SC species, constructed a transcriptome for each species, and then located each predicted transcript to the T.coronopifolia genome sequence. We annotated each predicted gene within the QTL and found two strong candidates for SI breakdown. Each gene has a coding sequence insertion/deletion mutation within the SC species that produces a truncated protein. Homologs of each gene have been implicated in pollen development, pollen germination, and pollen tube growth in other species.

<b>Angiosperm diversity in Doaba region of Punjab, India</b>

The angiosperms diversity was studied in Doaba region of Punjab, India. A total of 464 species belonging to 337 genera and 99 families were recorded during this study. Of these, 88% are dicots and the remaining (12%) are monocots. The data contain wild, cultivated and ornamental species. Fabaceae is the most dominant family with 60 species followed by Asteraceae (33), Poaceae (29), Euphorbiaceae (20), Amaranthaceae (18), Cucurbitaceae and Solanaceae (17 each). Amongst all the recorded species, 255 were herbs, 65 shrubs, 85 trees and 59 climbers. Six species have been added to the flora of Punjab. Present investigation has indicated that, Doaba region of Punjab has rich angiosperm diversity and need of the hour is its documentation and conservation.

Diversity and composition of herbaceous angiosperms along gradients of elevation and forest-use intensity.

Terrestrial herbs are important elements of tropical forests; however, there is a lack of research on their diversity patterns and how they respond to different intensities of forest-use. The aim of this study was to analyze the diversity of herbaceous angiosperms along gradients of elevation (50 m to 3500 m) and forest-use intensity on the eastern slopes of the Cofre de Perote, Veracruz, Mexico. We recorded the occurrence of all herbaceous angiosperm species within 120 plots of 20 m x 20 m each. The plots were located at eight study locations separated by ~500 m in elevation and within three different habitats that differ in forest-use intensity: old-growth, degraded, and secondary forest. We analyzed species richness and floristic composition of herb communities among different elevations and habitats. Of the 264 plant species recorded, 31 are endemic to Mexico. Both α- and γ-diversity display a hump-shaped relation to elevation peaking at 2500 m and 3000 m, respectively. The relative contribution of between-habitat β-diversity to γ-diversity also showed a unimodal hump whereas within-habitat β-diversity declined with elevation. Forest-use intensity did not affect α-diversity, but β-diversity was high between old-growth and secondary forests. Overall, γ-diversity peaked at 2500 m (72 species), driven mainly by high within- and among-habitat β-diversity. We infer that this belt is highly sensitive to anthropogenic disturbance and forest-use intensification. At 3100 m, high γ-diversity (50 species) was driven by high α- and within-habitat β-diversity. There, losing a specific forest area might be compensated if similar assemblages occur in nearby areas. The high β-diversity and endemism suggest that mixes of different habitats are needed to sustain high γ-richness of terrestrial herbs along this elevational gradient.

Wood functional disparity lags behind taxonomic diversification in angiosperms

Early angiosperm fossil record shows a remarkably low wood structural diversity relative to that exhibited by reproductive structures. As wood anatomical traits are related to plant function, paucity of early wood structural differentiation suggests a delay of functional diversification relative to the explosive taxonomic accumulation of the group. We assembled a wood anatomy dataset of over 1000 extant species from Argentina, Brazil, China, Mexico, USA and Suriname to determine the disparification patterns of the cell types associated with the three main wood functional axes: conduction, support and storage. We found that most traits had a temporal shift in their evolutionary patterns, with early conservatism followed by high lability towards the present. Our results indicate that a surge in functional wood traits lability took place after the initial taxonomic diversification in the early Cretaceous and support the observed low wood structural diversity observed in the early angiosperm fossil record. Increased trait lability likely allowed evolutionary flexibility by lifting developmental constraints and boosted the evolution of different cell types involved in multiple wood functions and their associated ecological role. The diversification in wood function coincides with the escalation of angiosperm tree size and leaf hydraulic capacity and likely contributed to the subsequent ecological expansion of the angiosperms.

The ancestral flower of angiosperms and its early diversification

Recent advances in molecular phylogenetics and a series of important palaeobotanical discoveries have revolutionized our understanding of angiosperm diversification. Yet, the origin and early evolution of their most characteristic feature, the flower, remains poorly understood. In particular, the structure of the ancestral flower of all living angiosperms is still uncertain. Here we report model-based reconstructions for ancestral flowers at the deepest nodes in the phylogeny of angiosperms, using the largest data set of floral traits ever assembled. We reconstruct the ancestral angiosperm flower as bisexual and radially symmetric, with more than two whorls of three separate perianth organs each (undifferentiated tepals), more than two whorls of three separate stamens each, and more than five spirally arranged separate carpels. Although uncertainty remains for some of the characters, our reconstruction allows us to propose a new plausible scenario for the early diversification of flowers, leading to new testable hypotheses for future research on angiosperms.

Evolution and developmental genetics of floral display—A review of progress

AbstractAngiosperms evolved a great diversity of ways to display their flowers for reproductive success by variation in floral color, size, shape, scent, arrangements, and flowering time. The various innovations in floral forms and the aggregation of flowers into different kinds of inflorescences can drive new ecological adaptations, speciation, and angiosperm diversification. Evolutionary developmental biology (evo‐devo) seeks to uncover the developmental and genetic basis underlying morphological diversification. Advances in the developmental genetics of floral display have provided a foundation for insights into the genetic basis of floral and inflorescence evolution. A number of regulatory genes controlling floral and inflorescence development have been identified in model plants (e.g., Arabidopsis thaliana, Antirrhinum majus) using forward genetics and conserved functions of many of these genes across diverse non‐model species have been revealed by reverse genetics. Gene‐regulatory networks that mediated the developmental progresses of floral and inflorescence development have also been established in some plant species. Meanwhile, phylogeny‐based comparative analysis of morphological and genetic character has enabled the identification of key evolutionary events that lead to morphological complexity and diversification. Here we review the recent progress on evo‐devo studies of floral display including floral symmetry, petal fusion, floral color, floral scent, and inflorescences. We also review the molecular genetic approaches applied to plant evo‐devo studies and highlight the future directions of evo‐devo.

Polyploidy and interspecific hybridization: partners for adaptation, speciation and evolution in plants.

Polyploidy or whole-genome duplication is now recognized as being present in almost all lineages of higher plants, with multiple rounds of polyploidy occurring in most extant species. The ancient evolutionary events have been identified through genome sequence analysis, while recent hybridization events are found in about half of the world's crops and wild species. Building from this new paradigm for understanding plant evolution, the papers in this Special Issue address questions about polyploidy in ecology, adaptation, reproduction and speciation of wild and cultivated plants from diverse ecosystems. Other papers, including this review, consider genomic aspects of polyploidy. Discovery of the evolutionary consequences of new, evolutionarily recent and ancient polyploidy requires a range of approaches. Large-scale studies of both single species and whole ecosystems, with hundreds to tens of thousands of individuals, sometimes involving 'garden' or transplant experiments, are important for studying adaptation. Molecular studies of genomes are needed to measure diversity in genotypes, showing ancestors, the nature and number of polyploidy and backcross events that have occurred, and allowing analysis of gene expression and transposable element activation. Speciation events and the impact of reticulate evolution require comprehensive phylogenetic analyses and can be assisted by resynthesis of hybrids. In this Special Issue, we include studies ranging in scope from experimental and genomic, through ecological to more theoretical. The success of polyploidy, displacing the diploid ancestors of almost all plants, is well illustrated by the huge angiosperm diversity that is assumed to originate from recurrent polyploidization events. Strikingly, polyploidization often occurred prior to or simultaneously with major evolutionary transitions and adaptive radiation of species, supporting the concept that polyploidy plays a predominant role in bursts of adaptive speciation. Polyploidy results in immediate genetic redundancy and represents, with the emergence of new gene functions, an important source of novelty. Along with recombination, gene mutation, transposon activity and chromosomal rearrangement, polyploidy and whole-genome duplication act as drivers of evolution and divergence in plant behaviour and gene function, enabling diversification, speciation and hence plant evolution.

Uncertain pollination environment promotes the evolution of a stable mixed reproductive system in the self-incompatible Hypochaeris salzmanniana (Asteraceae).

The transition from outcrossing to selfing is a repeated pattern in angiosperm diversification and according to general theory this transition should occur quickly and mixed reproductive systems should be infrequent. However, a large proportion of flowering plants have mixed reproductive systems, even showing inbreeding depression. Recently, several theoretical studies have shown that mixed mating systems can be stable, but empirical studies supporting these assumptions are still scarce. Hypochaeris salzmanniana, an annual species with populations differing in their self-incompatibility expression, was used as a study case to assess the stability of its mixed reproductive system. Here a descriptive study of the pollination environment was combined with measurements of the stability of the self-incompatibility system, outcrossing rate, reproductive assurance and inbreeding depression in four populations for two consecutive years. The reproductive system of populations exhibited a geographical pattern: the proportion of plants decreased from west to east. Pollinator environment also varied geographically, being less favourable from west to east. The self-incompatibility expression of some populations changed markedly in only one year. After selfing, progeny was mainly self-compatible, while after outcrossing both self-incompatible and self-compatible plants were produced. In general, both reproductive assurance and high inbreeding depression were found in all populations and years. The lowest values of inbreeding depression were found in 2014 in the easternmost populations, which experienced a marked increase in self-compatibility in 2015. The mixed reproductive system of H. salzmanniana seems to be an evolutionarily stable strategy, with selfing conferring reproductive assurance when pollinator attendance is low, but strongly limited by inbreeding depression. The fact that the highest frequencies of self-compatible plants appeared in the environments most unfavourable to pollination suggests that these plants are selected in these sites, although high rates of inbreeding depression should impede the complete loss of self-incompatibility. In H. salzmanniana, year-to-year changes in the frequency of self-incompatible individuals are directly derived from the balance between reproductive assurance and inbreeding depression.

How did the flower originate?

The flower is a characteristic feature of angiosperms. The innovation and diversification of the flower significantly improve the reproductive efficiency and environmental adaptation of angiosperms, and thus contribute to the great success of angiosperms in terrestrial ecosystem. How the flower originated is a major aspect of Darwin’s “abominable mystery” of the origin and rapid diversification of angiosperms, and has long been a basic question of evolutionary biology and botany with intense investigations. Over the past two centuries, many theories and hypotheses have been proposed to explain the origin of the flower based on a broad spectrum of multidisciplinary research involving comparative morphology, paleontology, anatomy, and developmental biology. However, the answer to how the flower originated has remained controversial because the phylogeny of the seed plants was poorly resolved and the molecular basis of flower development was not unraveled. In 2005, Science posed this question as one of the 125 most challenging scientific questions in a special issue to commemorate the 125th anniversary of the journal, implying that the study of the process and mechanisms of the origin of the flower is still a hot topic of current evolutionary biology and botany. In recent years, thanks to the rise and rapid progress in molecular phylogenetics, evolutionary developmental biology (evo-devo), and genomics, new ideas have been brought and our knowledge on the origin of the flower has been updated. Now, it is generally believed that (i) the flower is a determinate, compressed, and bisexual reproductive axis, which consists of perianth, androecium, and gynoecium from the outer to the inner; (ii) the flower did not originate abruptly but evolved gradually, with bisexuality being the first step, followed by the compression of reproductive axis and the evolution of the floral determinacy, and the floral structural elements originated at different evolutionary stages; and (iii) the floral MADS-box genes that specify the identities of floral organs have experienced duplication events prior to the origin of the angiosperms and the changes in their expression patterns, functions, and modes of protein-protein interaction have contributed to the origin of the flower. The new advances have not only corrected some mistakes in previous theories and models, stimulated the proposal of new and testable hypotheses, but also revealed the contribution of the evolution of floral MADS-box genes to the origin of the flower. However, previous studies can only provide general explanations for how the flower as a whole originated, but are insufficient for a complete understanding of the underlying mechanisms of the origins of different floral organs. In this review, we summarize the theories and hypotheses explaining the origin of the flower and floral organs. On the basis of this framework, we provide the current understanding of the flower itself and its origin. In our opinion, changes of many “small” key characters have been involved in the origin of the flower and the establishment of its basic structure. We propose that elucidation of the mechanisms underlying the evolution of these characters is the prerequisite for understanding the intrinsic basis for the origin of the flower.

Fire biases the production of charred flowers: Implications for the Cretaceous fossil record

The radiation of angiosperm lineages during the Cretaceous Period (145.5–65.5 Ma) initiated one of the greatest floral turnovers to have occurred on our planet. Much of our understanding of the floral biology and diversity of these early angiosperms derives from exceptionally preserved charcoalified and coalified Cretaceous fossil floras. Although fire played an integral role in the production of charred early angiosperm flowers, research has not considered whether the fire is capable of creating a bias in the nature of the charcoalified flowers that are produced. Here we use calorimetry to experimentally produce morphologically variable charcoalified flowers. Our findings indicate that combustion behavior, floral structure, the number of flowers, and their arrangement (inflorescence) all affect the number of charred flowers that are produced. These observations suggest that charred flowers are not equally likely to be represented in Cretaceous charcoal assemblages, and some species may be missing from the fossil record entirely. This may in turn alter our understanding of early angiosperm evolution and the fossil record of fire.

Updated angiosperm family tree for analyzing phylogenetic diversity and community structure

ABSTRACT The computation of phylogenetic diversity and phylogenetic community structure demands an accurately calibrated, high-resolution phylogeny, which reflects current knowledge regarding diversification within the group of interest. Herein we present the angiosperm phylogeny R20160415.new, which is based on the topology proposed by the Angiosperm Phylogeny Group IV, a recently released compilation of angiosperm diversification. R20160415.new is calibratable by different sets of recently published estimates of mean node ages. Its application for the computation of phylogenetic diversity and/or phylogenetic community structure is straightforward and ensures the inclusion of up-to-date information in user specific applications, as long as users are familiar with the pitfalls of such hand-made supertrees.

Diversification rates in Antirrhineae (Plantaginaceae): The contribution of range shifts and pollination modes

The relationship between range and diversification is an enduring evolutionary question. The rich angiosperm diversity stems from several factors including variations in geographical distribution and floral morphology, which tend to correlate with different pollinator preference in many taxa. Pollinator diversity varies among different regions, thus range shifts can play an important role in increasing divergence by predisposing clades to floral shifts. Antirrhineae is an ideal model to examine the effect of range shifts and pollination modes on diversification, because the tribe is distributed in the Old World and the New World with representatives exhibiting hummingbird pollination in the New World, and bee pollination in the Old World and the New World. Using ancestral reconstructions and phylogenetic modeling, this study investigated the effects of geographic distribution and pollination modes on the macroevolution of the tribe Antirrhineae. Our age-range correlation analysis showed young nodes had more range overlap than older nodes in the phylogeny, suggesting sympatric speciation as a contributing factor to the diversification of the tribe. We observed similar rates of diversification throughout time with no evident rate shifts within the tribe. Old World and New World lineages have similar speciation rates in Antirrhineae, and pollination mode did not have a significant effect on the diversification of the tribe. However, we found evidence for increased diversification rates through long-distance dispersal events, which occurred between the Old World and the New World four times throughout the evolutionary history of Antirrhineae. Therefore, we conclude that long-distance dispersal was a strong contributor to the diversity within Antirrhineae.

Hummingbird pollination and the diversification of angiosperms: an old and successful association in Gesneriaceae.

The effects of specific functional groups of pollinators in the diversification of angiosperms are still to be elucidated. We investigated whether the pollination shifts or the specific association with hummingbirds affected the diversification of a highly diverse angiosperm lineage in the Neotropics. We reconstructed a phylogeny of 583 species from the Gesneriaceae family and detected diversification shifts through time, inferred the timing and amount of transitions among pollinator functional groups, and tested the association between hummingbird pollination and speciation and extinction rates. We identified a high frequency of pollinator transitions, including reversals to insect pollination. Diversification rates of the group increased through time since 25 Ma, coinciding with the evolution of hummingbird-adapted flowers and the arrival of hummingbirds in South America. We showed that plants pollinated by hummingbirds have a twofold higher speciation rate compared with plants pollinated by insects, and that transitions among functional groups of pollinators had little impact on the diversification process. We demonstrated that floral specialization on hummingbirds for pollination has triggered rapid diversification in the Gesneriaceae family since the Early Miocene, and that it represents one of the oldest identified plant-hummingbird associations. Biotic drivers of plant diversification in the Neotropics could be more related to this specific type of pollinator (hummingbirds) than to shifts among different functional groups of pollinators.

How (much) do flowers vary? Unbalanced disparity among flower functional modules and a mosaic pattern of morphospace occupation in the order Ericales.

The staggering diversity of angiosperms and their flowers has fascinated scientists for centuries. However, the quantitative distribution of floral morphological diversity (disparity) among lineages and the relative contribution of functional modules (perianth, androecium and gynoecium) to total floral disparity have rarely been addressed. Focusing on a major angiosperm order (Ericales), we compiled a dataset of 37 floral traits scored for 381 extant species and nine fossils. We conducted morphospace analyses to explore phylogenetic, temporal and functional patterns of disparity. We found that the floral morphospace is organized as a continuous cloud in which most clades occupy distinct regions in a mosaic pattern, that disparity increases with clade size rather than age, and that fossils fall in a narrow portion of the space. Surprisingly, our study also revealed that among functional modules, it is the androecium that contributes most to total floral disparity in Ericales. We discuss our findings in the light of clade history, selective regimes as well as developmental and functional constraints acting on the evolution of the flower and thereby demonstrate that quantitative analyses such as the ones used here are a powerful tool to gain novel insights into the evolution and diversity of flowers.