Variation In Floral Morphology Research Articles

A phylogeny of the evening primrose family (Onagraceae) using a target enrichment approach with 303 nuclear loci

BackgroundThe evening primrose family (Onagraceae) includes 664 species (803 taxa) with a center of diversity in the Americas, especially western North America. Ongoing research in Onagraceae includes exploring striking variation in floral morphology, scent composition, and breeding system, as well as the role of these traits in driving diversity among plants and their interacting pollinators and herbivores. However, these efforts are limited by the lack of a comprehensive, well-resolved phylogeny. Previous phylogenetic studies based on a few loci strongly support the monophyly of the family and the sister relationship of the two largest tribes but fail to resolve several key relationships.ResultsWe used a target enrichment approach to reconstruct the phylogeny of Onagraceae using 303 highly conserved, low-copy nuclear loci. We present a phylogeny for Onagraceae with 169 individuals representing 152 taxa sampled across the family, including extensive sampling within the largest tribe, Onagreae. Deep splits within the family are strongly supported, whereas relationships among closely related genera and species are characterized by extensive conflict among individual gene trees.ConclusionsThis phylogenetic resource will augment current research projects focused throughout the family in genomics, ecology, coevolutionary dynamics, biogeography, and the evolution of characters driving diversification in the family.

3D pollination biology using micro-computed tomography and geometric morphometrics in Theobroma cacao.

Imaging technologies that capture three-dimensional (3D) variation in floral morphology at micro- and nano-resolutions are increasingly accessible. In herkogamous flowers, such as those of Theobroma cacao, structural barriers between anthers and stigmas represent bottlenecks that restrict pollinator size and access to reproductive organs. To study the unresolved pollination biology of cacao, we present a novel application of micro-computed tomography (micro-CT) using floral dimensions to quantify pollinator functional size limits. We generated micro-CT data sets from field-collected flowers and museum specimens of potential pollinators. To compare floral variation, we used 3D Slicer to place landmarks on the surface models and performed a geometric morphometric (GMM) analysis using geomorph R. We identified the petal side door (an opening between the petal hoods and filament) as the main bottleneck for pollinator access. We compared its mean dimensions with proposed pollinators to identify viable candidates. We identified three levels of likelihood for putative pollinators based on the number of morphological (body) dimensions that fit through the petal side door. We also found floral reward microstructures whose presence and location were previously unclear. Using micro-CT and GMM to study the 3D pollination biology of cacao provides new evidence for predicting unknown pollinators. Incorporating geometry and floral rewards will strengthen plant-pollinator trait matching models for cacao and other species.

The novel developed microsatellite markers revealed potential hybridization among Cymbidium species and the interspecies sub-division of C. goeringii and C. ensifolium

BackgroundOrchids (Cymbidium spp.) exhibit significant variations in floral morphology, pollinator relations, and ecological habitats. Due to their exceptional economic and ornamental value, Cymbidium spp. have been commercially cultivated for centuries. SSR markers are extensively used genetic tools for biology identification and population genetics analysis.ResultIn this study, nine polymorphic EST-SSR loci were isolated from Cymbidium goeringii using RNA-Seq technology. All nine SSR loci showed transferability in seven other congeneric species, including 51 cultivars. The novel SSR markers detected inter-species gene flow among the Cymbidium species and intra-species sub-division of C. goeringii and C. ensifolium, as revealed by neighborhood-joining and Structure clustering analyses.ConclusionIn this study, we developed nine microsatellites using RNA-Seq technology. These SSR markers aided in detecting potential gene flow among Cymbidium species and identified the intra-species sub-division of C. goeringii and C. ensifolium.

Convergence without divergence in North American red-flowering Silene.

Combinations of correlated floral traits have arisen repeatedly across angiosperms through convergent evolution in response to pollinator selection to optimize reproduction. While some plant groups exhibit very distinct combinations of traits adapted to specific pollinators (so-called pollination syndromes), others do not. Determining how floral traits diverge across clades and whether floral traits show predictable correlations in diverse groups of flowering plants is key to determining the extent to which pollinator-mediated selection drives diversification. The North American Silene section Physolychnis is an ideal group to investigate patterns of floral evolution because it is characterized by the evolution of novel red floral color, extensive floral morphological variation, polyploidy, and exposure to a novel group of pollinators (hummingbirds). We test for correlated patterns of trait evolution that would be consistent with convergent responses to selection in the key floral traits of color and morphology. We also consider both the role of phylogenic distance and geographic overlap in explaining patterns of floral trait variation. Inconsistent with phenotypically divergent pollination syndromes, we find very little clustering of North American Silene into distinct floral morphospace. We also find little evidence that phylogenetic history or geographic overlap explains patterns of floral diversity in this group. White- and pink-flowering species show extensive phenotypic diversity but are entirely overlapping in morphological variation. However, red-flowering species have much less phenotypic disparity and cluster tightly in floral morphospace. We find that red-flowering species have evolved floral traits that align with a traditional hummingbird syndrome, but that these trait values overlap with several white and pink species as well. Our findings support the hypothesis that convergent evolution does not always proceed through comparative phenotypic divergence, but possibly through sorting of standing ancestral variation.

Taxonomic analysis of certain taxa of Epipactis in Slovenia

The predominantly allogamous Broad-leaved Helleborines (Epipactis helleborine) and the predominantly autogamous Narrow-lipped Helleborines (Epipactis leptochila) represent two taxonomically complex groups with great morphological diversity and close genetic relationships at the subspecies level. They are influenced by environment, clinal variability, hybridization between allogamous taxa, and in particularly by speciation through transitions from allogamy to autogamy. We analysed floral traits, genome size and performed molecular analyses (Internal transcribed spacer region, ITS; Amplified Fragment Length Polymorphism, AFLP) of several individuals of E. helleborine and E. leptochila aggregate from different geographical regions in Slovenia, focusing on intermediate traits of E. helleborine subsp. moratoria, E. helleborine subsp. leutei and E. leptochila subsp. neglecta. In order to successfully distinguish studied taxa, the main attention should be paid to the shape of the epichil and the ovary, as well as to the size ratio of sepals and petals. Among the microfloral characters, the shape and size of the lower margin of the stigma and staminodes are found to be supportive. E. neglecta clearly shows intermediate floral characteristics between E. leptochila and E. leutei, suggesting that the transition to autogamy evolved E. neglecta as an intermediate stage in the speciation process, coinciding with the colonisation of forest sites with lower light intensity. Analysis of genome size revealed significant differences, with E. neglecta having the greatest value. Using molecular markers, we were able to determine two main ribotype clusters within the E. helleborine group, which were also determined by AFLP analyses. E. leutei and E. neglecta formed two clearly defined subclusters within the E. leptochila lineage. The results of the presented study suggest that combining molecular markers and genome size with information on how variation in floral morphology is distributed, using multivariate analyses, is the most reliable way to gain improved insight into the relationships among the taxa analysed.

Elucidating the Evolutionary History ofOenotheraSect.Pachylophus(Onagraceae): A Phylogenomic Approach

Abstract—Oenotherasect.Pachylophushas proven to be a valuable system in which to study plant-insect coevolution and the drivers of variation in floral morphology and scent. Current species circumscriptions based on morphological characteristics suggest that the section consists of five species, one of which is subdivided into five subspecies. Previous attempts to understand species (and subspecies) relationships at a molecular level have been largely unsuccessful due to high levels of incomplete lineage sorting and limited phylogenetic signal from slowly evolving gene regions. In the present study, target enrichment was used to sequence 322 conserved protein-coding nuclear genes from 50 individuals spanning the geographic range ofOenotherasect.Pachylophus, with species trees inferred using concatenation and coalescent-based methods. Our findings concur with previous research in suggesting thatO. psammophilaandO. harringtoniiare nested within a paraphyleticOenothera cespitosa. By contrast, our results show clearly that the two annual species (O. cavernaeandO. brandegeei) did not arise from theO. cespitosalineage, but rather from a common ancestor ofOenotherasect.Pachylophus. Budding speciation as a result of edaphic specialization appears to best explain the evolution of the narrow endemic speciesO. harringtoniiandO. psammophila. Complete understanding of possible introgression among subspecies ofO. cespitosawill require broader sampling across the full geographical and ecological ranges of these taxa.

DISTYLY IN OREOCARYA CRASSIPES (BORAGINACEAE), AN ENDANGERED PLANT SPECIES

Oreocarya crassipes, an endangered angiosperm native to the Trans-Pecos region in southern Brewster County, Texas, exhibits distyly, a breeding system that includes two floral morphs with reciprocal positioning of the anthers and stigmas. The long-style (LS) morph has stigmas above the anthers, and the short-style (SS) morph produces anthers above the stigmas. In the present study, multiple aspects of distyly were examined across four populations of O. crassipes including morph ratios, variation in floral morphology, and patterns of macroscopic and microscopic floral development of the morphs. Morph ratios vary among populations, but for all of the samples pooled the ratio was 1 LS:1 SS. Distyly was observed to be well established in the species, with stigma height, anther height, and stigma-anther separation significantly different between the two morphs. Floral developmental patterns are similar to those in related species, suggesting a conserved and similarly co-opted developmental pathway for the origin of distyly in the genus and relatives.

Characterization of 30 microsatellite markers for distylous Primula denticulata (Primulaceae) using HiSeq sequencing.

Primula denticulata exhibits considerable variation in floral morphology and flowering phenology along elevational gradients in SW China. We isolated 30 microsatellite markers from P. denticulata to facilitate further investigation of population genetics and floral evolution in this species. We used the HiSeq X-Ten sequencing system to develop a set of markers, and measured polymorphism and genetic diversity in a sample of 72 individuals from three natural populations of P. denticulata subsp. denticulata. The markers displayed relatively high polymorphism, with the number of alleles ranging from two to seven (mean = 3.567). The observed and expected heterozygosity ranged from 0 to 1.000 and 0.041 to 0.702, respectively. Twenty-eight of the loci were also successfully amplified in P. denticulata subsp. sinodenticulata. The microsatellite markers we have identified will provide valuable tools for investigations of the population genetic structure, mating systems and phylogeography of the P. denticulata complex, and will help to address questions concerning the ecological and genetic mechanisms responsible for the evolution of reproductive traits in the species.

Relationship between interspecific pollen transfer and pistil length in sympatric congeners, Clerodendrum trichotomum and C. izuinsulare

AbstractInterspecific pollen transfer (IPT) often leads to reproductive interference. Although character displacement of reproductive traits in plants is often considered a consequence of reproductive interference, few studies have tested whether intraspecific variation in floral morphology changes the intensity of reproductive interference among pollinator‐sharing plants. We investigated whether intraspecific variation in pistil length changes the proportion of IPT (interspecific pollen transfer) in sympatric populations of Clerodendrum trichotomum and C. izuinsulare on the two islands. On Toshima Island, C. izuinsulare flowers with shorter pistils were significantly less likely to receive C. trichotomum pollen, and there was a slight tendency for longer pistiles of C. trichotomum flowers to receive less C. izuinsulare pollen, suggesting that IPT has caused character displacement in pistil length in these congeneric plants. In contrast, we did not detect any relationship between pistil length and the proportion of IPT for the two species on Niijima Island. The discrepancy between the islands may reflect differences in pollinator assemblages.

Taxonomic significance of vegetative and reproductive morphology in southern Africa Rhynchosia sect. Rhynchosia (Fabaceae: Papilionoideae, Phaseoleae)

Rhynchosia is the largest genus in the subtribe Cajaninae, tribe Phaseoleae. Due to the lack of a recent taxonomic revision in the genus, the species are poorly known and as a result, are difficult to identify. As part of our ongoing taxonomic studies on the genus in southern Africa, this paper presents a comparative study of vegetative and floral morphological variation in the 47 species currently recognised in the type section Rhynchosia in the region. This is with a view to provide useful diagnostic morphological characters that can be used to correctly identify species in the type section and in other sections. The study used morphological data from field observation, herbarium specimens, and literature. Stems, leaves, and floral structures were examined with a dissecting microscope. A stereoscope with a camera lucida attachment was used to draw the reproductive morphology. Although morphological characters seem to overlap between the sections, characters such as leaflets size, type of indumentum on leaflet surfaces, stipules shape, type and length of inflorescences, presence or absence of indumentum on standard petals, presence and absence of sculpturing on wing petals, as well as length of upper lobes of the calyx are useful in identifying species.

Patterns of floral morphology in relation to climate and floral visitors.

The diversity of floral morphology among plant species has long captured the interest of biologists and led to the development of a number of explanatory theories. Floral morphology varies substantially within species, and the mechanisms maintaining this diversity are diverse. One possibility is that spatial variation in the pollinator fauna drives the evolution of spatially divergent floral ecotypes adapted to the local suite of pollinators. Another possibility is that geographic variation in the abiotic environment and local climatic conditions favours different floral morphologies in different regions. Although both possibilities have been shown to explain floral variation in some cases, they have rarely been competed against one another using data collected from large spatial scales. In this study, we assess floral variation in relation to climate and floral visitors in four oil-reward-specialized pollination interactions. We used a combination of large-scale plant and pollinator samplings, morphological measures and climatic data. We analysed the data using spatial approaches, as well as traditional multivariate and structural equation modelling approaches. Our results indicate that the four species have different levels of specialization, and that this can be explained by their climatic niche breadth. In addition, our results show that, at least for some species, floral morphology can be explained by the identity of floral visitors, with climate having only an indirect effect. Our results demonstrate that, even in very specialized interactions, both biotic and abiotic variables can explain a substantial amount of intraspecific variation in floral morphology.

Comparative morphometry as a diagnostic tool applied to species delimitation in the genus Gastridium P. Beauv. (Poaceae)

Based on critical examination of both fresh and dried specimens and a morphometric analysis of herbarium specimens we performed a comparative study of the three closely related Gastridium (Poaceae, Tribe: Poeae, Subtribe: Agrostidinae) species G. ventricosum, G. phleoides and G. scabrum collected in Italy. The study aimed to provide new diagnostic tools to improve the taxonomy of the genus and confirm species delimitation. Variation in floral morphology in the three species was explored using seven quantitative and ten qualitative characters measured on 318 spikelets, both awned and unawned. Statistical methods, including principal components analysis (PCA) and non‐metric multidimensional scaling (NMDS), were used. Numerical analyses showed a general distinctness of spikelets and florets, consistent with the three studied species, and revealed among and within species variation patterns in both spikelet types. Accordingly, the most informative quantitative characters appeared to be the width and length of glumes and the length of awns, useful to distinguish G. phleoides which has the narrowest glumes and longer awns than the other species, while G. scabrum has the widest glumes. The most informative qualitative characters appeared to be the presence/absence of thick hairs or minute tubercles on the upper side of the lemma. The autonomy of the three studied species was confirmed. The taxonomic significance of the results is briefly discussed, and notes on the species distribution are included. Some nomenclatural and taxonomic notes on G. scabrum, of which literature still showed evidence of a general unawareness, are provided.

Variation in floral morphology in a hybrid complex of Cyclamen in Sardinia

ABSTRACTBackground: Hybridization is a key driver of plant speciation, and understanding ongoing hybridization provides insights into the underlying process. We studied a hybrid complex in Mediterranean Cyclamen between common C. repandum and rare C. balearicum on Sardinia.Aims: We analyzed variation in the frequency and morphology of different floral types to assess the degree of hybridization and analyze the ecological niche to better understand factors that influence the maintenance of hybrid populations.Methods: We recorded the frequency of the different flower color-types in 45 populations and measured floral traits in 10 of them. We characterized the spatial extent and climatic niche of this hybrid complex. We analyzed floral type variation in four traits (flower size, style and anther length, herkogamy).Results: Hybrid populations occupy a wide area on the NW coast of the island (~1000km2). Sites dominated by hybrid floral types are ecologically marginal for the common parent. The C. repandum-like type is present in all populations and shows a decrease in style and anther length and herkogamy in populations containing a greater proportion of hybrids.Conclusions: This hybrid complex provides an ideal situation to examine reproductive isolation due to variation in the ecological niche of different floral types.

Floral uniformity through evolutionary time in a species-rich tree lineage.

Changes in floral morphology are expected across evolutionary time and are often promoted as important drivers in angiosperm diversification. Such a statement, however, is in contrast to empirical observations of species-rich lineages that show apparent conservative floral morphologies even under strong selective pressure to change from their environments. Here, we provide quantitative evidence for prolific speciation despite uniform floral morphology in a tropical species-rich tree lineage. We analyse floral disparity in the environmental and phylogenetic context of Myrcia (Myrtaceae), one of the most diverse and abundant tree genera in Neotropical biomes. Variation in floral morphology among Myrcia clades is exceptionally low, even among distantly related species. Discrete floral specialisations do occur, but these are few, present low phylogenetic signal, have no strong correlation with abiotic factors, and do not affect overall macroevolutionary dynamics in the lineage. Results show that floral form and function may be conserved over large evolutionary time scales even in environments full of opportunities for ecological interactions and niche specialisation. Species accumulation in diverse lineages with uniform flowers apparently does not result from shifts in pollination strategies, but from speciation mechanisms that involve other, nonfloral plant traits.

The impact of floral morphology on genetic differentiation in two closely related biennial plant species.

The genetic diversity and structure of plant populations are determined by the interaction of three distinct processes: gene flow, genetic drift and natural selection. These processes are to some extent dependent on the mating system of plants, which in turn is largely determined by floral morphology and the level of herkogamy in particular. In this study, we used molecular markers to investigate the impact of floral morphology on genetic differentiation and structure in two closely related Centaurium species that display large variation in floral morphology across two distinct geographic regions in Europe (mainland Europe and the UK). Our results showed that genetic differences between regions and populations within regions were similar for both species, but that patterns of genetic structure largely depended on the observed variation in floral morphology. Populations of Centaurium erythraea showed higher genetic differentiation and clear isolation by distance (IBD) in mainland Europe, but limited IBD in the UK. Opposite patterns were found in Centaurium littorale, with higher genetic differentiation and significant IBD in populations sampled in the UK and lower genetic differentiation in Continental populations with no pattern of IBD. Overall, these results indicate that variation in floral morphology has a profound impact on structuring of genetic diversity, with populations displaying low levels of herkogamy showing the strongest patterns of genetic structuring and the reverse pattern in populations showing high levels of herkogamy.

Floral Morphology Differs Among New Northern Highbush Blueberry Cultivars

Variation in floral morphology and timing of bloom are common among cultivars of northern highbush blueberry (Vaccinium corymbosum L.). These differences can affect the ability of commercial pollinators to effectively pollinate and fertilize ovules, which can impact fruit set, berry size, and ultimate yields. New northern highbush blueberry cultivars may exhibit differences in flower morphology, which could impact pollination and fruit set. Evaluation of new cultivars compared to standard industry cultivars is of specific importance in predicting potential pollination constraints by honey bee (Apis mellifera), one of the primary pollinators in North America, and in developing optimal hive stocking densities. Three new cultivars (‘Blue Ribbon’, ‘Top Shelf’, and ‘Cargo’) were compared to an industry standard (‘Duke’) for floral morphology and relative bloom phenology. All new cultivars had significantly smaller flowers as compared to ‘Duke’; however, ‘Top Shelf’ flowers exhibited a unique characteristic whereby many flowers (81%) had partially fused petals. Reduced flower size of new cultivars suggests floral morphology may be a constraint to effective pollination by honey bees and/or these cultivars will require higher honey bee stocking densities for effective pollination. However, the partially unfused petals in ‘Top Shelf’ may provide improved exposure to the stamen and pistil, which could increase accessibility to pollinators like honey bee and promote pollination and fruit set.

Beyond pollinators: evolution of floral architecture with environment across the wild sunflowers (Helianthus, Asteraceae)

Background – There is a growing appreciation that the evolution of floral traits is shaped by selection not only from pollinators, but also factors like abiotic stress, florivory, and disease. Many such pressures impose counter-selection for smaller, less attractive flowers. In self-incompatible taxa, floral investment in attraction is required to ensure cross-pollination, setting up a potential energetic trade-off with investment in fecundity through pollen and seeds.Methods – This study assesses ecological and evolutionary causes of variation in floral morphology across the diverse genus Helianthus (Asteraceae), focusing on floral size, colour, water content, and relative investment in attractive but sterile ray florets versus non-showy but fertile disc florets.Key results – All floral traits were found to be highly evolutionarily labile, and the trade-off in relative investment between ray and disc florets was found to evolve independently of floral size. Both floral size and disc water content were strongly correlated with source site climate and soil characteristics, with larger heads and higher water content repeatedly evolving in more fertile and drier habitats consistent with aspects of the resource-cost and enemy-escape hypotheses of floral trait evolution, respectively. The evolution of disc colour and relative ray-disc investment was not explained by life history, flowering period, or source site environmental characteristics, suggesting that the evolution of these traits may instead be driven by other selective pressures, including perhaps pollinators.Conclusions – Together the results of this study suggest that the macroevolution of sunflower floral architecture is likely driven by selective pressures from multiple biotic and abiotic factors, with habitat environmental conditions influencing some but not all aspects of floral morphology.

Variation in floral morphology and plant reproductive success in four Ipomoea species (Convolvulaceae) with contrasting breeding systems.

This study tested the hypothesis that self-compatibility would be associated with floral traits that facilitate autonomous self-pollination to ensure reproduction under low pollinator visitation. In a comparison of two pairs of Ipomoea species with contrasting breeding systems, we predicted that self-compatible (SC) species would have smaller, less variable flowers, reduced herkogamy, lower pollinator visitation and higher reproductive success than their self-incompatible (SI) congeners. We studied sympatric species pairs, I. hederacea (SC)- I. mitchellae (SI) and I. purpurea (SC)-I. indica (SI), in Mexico, over two years. We quantified variation in floral traits and nectar production, documented pollinator visitation, and determined natural fruit and seed set. Hand-pollination and bagging experiments were conducted to determine potential for autonomous self-pollination and apomixis. Self-compatible Ipomoea species had smaller flowers and lower nectar production than SI species; however, floral variation and integration did not vary according to breeding system. Bees were primary pollinators of all species, but visitation rates were seven times lower in SC than SI species. SC species had a high capacity for autonomous self-pollination due to reduced herkogamy at the highest anther levels. Self-compatible species had two to six times higher fruit set than SI species. Results generally support the hypothesis that self-compatibility and autonomous self-pollination ensure reproduction under low pollinator visitation. However, high variation in morphological traits of SC Ipomoea species suggests they maintain variation through outcrossing. Furthermore, reduced herkogamy was associated with high potential for autonomous self-pollination, providing a reproductive advantage that possibly underlies transitions to self-compatibility in Ipomoea.

Genetic Diversity and Phylogenetic Behavior of Some Minor Legumes

Twenty-four accessions of twelve species minor legumes collected from the germplasm unit of the International Institute of Tropical Agriculture Ibadan, Nigeria were evaluated for their genetic diversities and phylogenetic relatedness. The accessions were planted into plots of 5 ridges of 5 meters long, spaced 1 meter apart and replicated three times at the Federal University Oye-Ekiti Teaching and Research Farm. The diversity and the relative phylogeny of the accessions were assessed through their floral morphological differences and the mean values between two accessions were evaluated by descriptive statistics. Principal component analysis was employed to identify the most discriminatory floral morphological traits and the similarities among the 24 accessions were assessed by cluster analysis (CA). Descriptive statistics through Duncan multiple range test adopted revealed genetic diversity and phylogenetic relatedness among the accessions. The first two principal component axes explained 64.66% of the total floral morphological variation. Standard petal length, calyx lobe length and stipule length contributed most of the variations in the legume accession. CA grouped the 24 accessions into six clusters. The study revealed intra-specific similarities and inter-specific floral morphological differences among the studied accessions.

Characterizing Floral Symmetry in the Core Goodeniaceae with Geometric Morphometrics.

Core Goodeniaceae is a clade of ~330 species primarily distributed in Australia. Considerable variation in flower morphology exists within this group and we aim to use geometric morphometrics to characterize this variation across the two major subclades: Scaevola sensu lato (s.l.) and Goodenia s.l., the latter of which was hypothesized to exhibit greater variability in floral symmetry form. We test the hypothesis that floral morphological variation can be adequately characterized by our morphometric approach, and that discrete groups of floral symmetry morphologies exist, which broadly correlate with subjectively determined groups. From 335 images of 44 species in the Core Goodeniaceae, two principal components were computed that describe >98% of variation in all datasets. Increasing values of PC1 ventralize the dorsal petals (increasing the angle between them), whereas increasing values of PC2 primarily ventralize the lateral petals (decreasing the angle between them). Manipulation of these two morphological “axes” alone was sufficient to recreate any of the general floral symmetry patterns in the Core Goodeniaceae. Goodenia s.l. exhibits greater variance than Scaevola s.l. in PC1 and PC2, and has a significantly lower mean value for PC1. Clustering clearly separates fan-flowers (with dorsal petals at least 120° separated) from the others, whereas the distinction between pseudo-radial and bilabiate clusters is less clear and may form a continuum rather than two distinct groups. Transitioning from the average fan-flower to the average non-fan-flower is described almost exclusively by PC1, whereas PC2 partially describes the transition between bilabiate and pseudo-radial morphologies. Our geometric morphometric method accurately models Core Goodeniaceae floral symmetry diversity.