Floral Syndromes Research Articles

Unveiling Thrips (Thysanoptera) as Nature's Unsung Pollinators: A Survey From Obligatory Thripophily to Thrips as Supplementary Pollinators

ABSTRACTThrips are minute, paraneopteran insects with diverse ecological histories and plant associations, encompassing herbivory, fungivory, pollination and predation. They are typically not widely adored insects as many species are regarded to be destructive crop pests and vectors of crop diseases. Nevertheless, certain thrips play a significant role in pollination as they traverse from flower to flower with pollen attached to their bodies. However, most studies on relationships between flowering plants and pollinators have overlooked the prevalence and association of thrips with flowers, and the pollination services were often incorrectly attributed to wind, bees or other agents. This is primarily due to the minute size and cryptic behaviour of thrips, their limited range of movement and minimal structural modifications to carry and disperse pollen. In recent times, the involvement of thrips in pollination was investigated by many researchers and their role was established partly or fully in several angiosperm families. Their role in pollination through specialised thripophily, as minor or secondary pollinators, or via ambophily is well‐established now. The present paper reviews the evidence of pollen transfer by thrips, obligate and nonobligate pollination relationships between plants and pollinator thrips, evolutionary aspects of thripophily, morphological and physiological adaptations in thrips and floral syndromes associated with thripophily.

Floral morphology is associated with pollen deposition patterns on moth bodies

AbstractFloral syndromes can be a useful tool for predicting the identity of pollinators from floral morphology. However, the reliability of floral syndromes are still debated in the literature, and can often result in effective pollinators being overlooked. Pollination by moths has historically been associated with a floral syndrome comprising white tubular flowers that are heavily scented at night, but there have been few experimental tests of this association. To test whether moths preferentially land on flowers that are white and tubular, we allowed two moth species (Agrotis ipsilon (Hufnaggel, 1766) and Ichneutica mutans (Walker, 1857)) to choose freely between three plant species (Vaccinium corymbosum, Ericaceae, Pittosporum tenuifolium, Pittosporaceae, and two forms of Leptospermum scoparium, Myrtaceae) which represent four different floral morphologies. Anthers on the flowers were marked with fluorescent powder dye (pollen‐tracker), with the presence of pollen‐tracker on moth bodies after the experiment indicating floral visitation. We detected no floral preferences for any of the plant species by either moth species, suggesting moths will visit flowers that lack features associated with the syndrome even when in the presence of white, tubular flowers which might be predicted to be more attractive to moths. We also examined moth bodies to determine where pollen‐tracker was carried most often and if this varied among the floral types. Our results indicate that some moth body parts may be more important than others for pollen transfer, depending on the morphology of the flowers visited. After visiting tubular flowers (Vaccinium and Pittosporum), pollen‐tracker was most often located on the proboscis, but after visiting open‐access flowers (Leptospermum) pollen‐tracker was most often located on the legs. Future studies looking at the presence of pollen on moth bodies should consider this and ensure the entire moth body is examined for the presence of pollen.

Spatial pattern and ecological adaptation of heterostylous and homostylous species of Primula in China

Abstract Floral syndrome is one of the key components of plant pollination syndromes, affecting variety of evolutionary and ecological processes in angiosperms. The evolutionary transition from self-incompatible heterostyly to self-compatible homostyly occurred repeatedly in angiosperm families. Although the evolution of heterostyly and homostyly has been deeply studied, our understanding on their differences in ecological strategies is still lacking. In this work, using the floral syndrome and distributions of the Primula in China we compared the spatial pattern of floral syndrome frequency and its climatic determinants. Our results reveal that distylous and homostylous Primula have similar primary centers of species diversity in southwest China, while distylous species have larger range size than homostylous ones. Temperature seasonality is the dominant climate factor of these geographic patterns, but its effect is much stronger in distylous than in homostylous Primula. Distylous species have larger flower size and number, and fruit size than homostylous ones. Climate, especially temperature seasonality mainly influenced species range size via its effects on floral syndrome. Our study suggests that homostyly is likely derived from heterostylous ancestors in similar geographical context, and larger reproductive investment in floral phenotype may provide compensatory mechanisms for obligate out-breeding heterostyly. Future investigations regarding the evolutionary history and tolerance or resistance to environmental change between distyly and homostyly may greatly advance our understanding of their spatial pattern and adaptative differences.

An evolutionary disruption of the buzz pollination syndrome in neotropical montane plants.

Under pollinator limitations, specialized pollination syndromes may evolve toward contrasting responses: a generalized syndrome with increased pollinator attraction, pollinator reward, and pollen transfer capacity; or the selfing syndrome with increased self-pollen deposition, but reduced pollinator attraction and pollen transfer capacity. The buzz-pollination syndrome is specialized to explore female vibrating bees as pollinators. However, vibrating bees become less-active pollinators at montane areas of the Atlantic Forest (AF) domain. This study investigated whether the specialized buzz-pollination syndrome would evolve toward an alternative floral syndrome in montane areas of the AF domain, considering a generalized and the selfing syndromes as alternative responses. We utilized a lineage within the buzz-pollinated Miconia as study system, contrasting floral traits between montane AF-endemic and non-endemic species. We measured and validated floral traits that were proxies for pollinator attraction, reward access, pollen transfer capacity, and self-pollen deposition. We inferred the evolution of floral trait via phylogenetic comparative methods. AF-endemic species have selectively evolved greater reward access and more frequently had generalist pollination. Nonetheless, AF-endemic species also have selectively evolved toward lower pollen transfer capacity and greater self pollination. These patterns indicated a complex evolutionary process that has jointly favored a generalized and the selfing syndromes. The buzz pollination syndrome can undergo an evolutionary disruption in montane areas of the AF domain. This floral syndrome is likely more labile than often assumed, allowing buzz-pollinated plants to reproduce in environments where vibrating bees are less-reliable pollinators.

Gradual pollen presentation in Vaccinium corymbosum 'Bluecrop': an adaptive mechanism to improve pollination efficiency and outcrossing.

Gradual pollen presentation is a plant reproductive mechanism to improve pollination efficiency and accuracy and promote outcrossing. Vaccinium corymbosum 'Bluecrop' has a typical gradual pollen presentation mechanism. 'Bluecrop' exhibits an inverted bell-shaped flower with a white coloration. By investigating the flower syndrome, pollination characteristics, pollination efficiency, and breeding system of 'Bluecrop', this study aims to explore the adaptive significance of these traits. The results showed 'Bluecrop' released pollen gradually through anther poricidal dehiscence. Among different pollinators, Apis mellifera and Bombus can pollinate effectively, and the mechanism of gradual pollen presentation significantly improved the efficiency of pollen transfer. This characteristic limits the amount of pollen removed by the pollinators and prolongs pollen presentation, thus attracting more pollinators and thereby increasing male fitness. The nectar secretion of 'Bluecrop' is gradual, with a large nectar production and a long phase of nectar secretion, enhance visitation frequencies and the chances of successful pollination. At the same time, campanulate corolla can protect pollen as well as nectar from waste due to environmental factors and other effects. The breeding system of 'Bluecrop' relies mainly on outcrossing because of its low affinity for self-fertilization and good interaction with pollinating insects. Thus, the special floral syndrome and the mechanism of secondary pollen presentation are significant in improving pollination efficiency and promoting the reproductive success of 'Bluecrop' by outcrossing. It can provide a certain theoretical basis for the future propagation breeding of 'Bluecrop'.

Shades of white: The Petunia long corolla tube clade evolutionary history.

Delimiting species is challenging in recently diverged species, and adaptive radiation is fundamental to understanding the evolutionary processes because it requires multiple ecological opportunities associated with adaptation to biotic and abiotic environments. The young Petunia genus (Solanaceae) is an excellent opportunity to study speciation because of its association with pollinators and unique microenvironments. This study evaluated the phylogenetic relationships among a Petunia clade species with different floral syndromes that inhabit several environments. We based our work on multiple individuals per lineage and employed nuclear and plastid phylogenetic markers and nuclear microsatellites. The phylogenetic tree revealed two main groups regarding the elevation of the distribution range, whereas microsatellites showed high polymorphism-sharing splitting lineages into three clusters. Isolation by distance, migration followed by new environment colonization, and shifts in floral syndrome were the motors for lineage differentiation, including infraspecific structuring, which suggests the need for taxonomic revision in the genus.

A few essential genetic loci distinguish Penstemon species with flowers adapted to pollination by bees or hummingbirds.

In the formation of species, adaptation by natural selection generates distinct combinations of traits that function well together. The maintenance of adaptive trait combinations in the face of gene flow depends on the strength and nature of selection acting on the underlying genetic loci. Floral pollination syndromes exemplify the evolution of trait combinations adaptive for particular pollinators. The North American wildflower genus Penstemon displays remarkable floral syndrome convergence, with at least 20 separate lineages that have evolved from ancestral bee pollination syndrome (wide blue-purple flowers that present a landing platform for bees and small amounts of nectar) to hummingbird pollination syndrome (bright red narrowly tubular flowers offering copious nectar). Related taxa that differ in floral syndrome offer an attractive opportunity to examine the genomic basis of complex trait divergence. In this study, we characterized genomic divergence among 229 individuals from a Penstemon species complex that includes both bee and hummingbird floral syndromes. Field plants are easily classified into species based on phenotypic differences and hybrids displaying intermediate floral syndromes are rare. Despite unambiguous phenotypic differences, genome-wide differentiation between species is minimal. Hummingbird-adapted populations are more genetically similar to nearby bee-adapted populations than to geographically distant hummingbird-adapted populations, in terms of genome-wide dXY. However, a small number of genetic loci are strongly differentiated between species. These approximately 20 "species-diagnostic loci," which appear to have nearly fixed differences between pollination syndromes, are sprinkled throughout the genome in high recombination regions. Several map closely to previously established floral trait quantitative trait loci (QTLs). The striking difference between the diagnostic loci and the genome as whole suggests strong selection to maintain distinct combinations of traits, but with sufficient gene flow to homogenize the genomic background. A surprisingly small number of alleles confer phenotypic differences that form the basis of species identity in this species complex.

Chasmogamy and entomophily in Burmannia disticha (Burmanniaceae).

Burmannia shows a set of floral traits that suggest elaborate mechanisms of animal-mediated pollen transfer. These include flower coloration, septal nectaries and a long and narrow floral chamber. The stamens are synorganized with the common style restricting the entrance to the floral chamber, sometimes forming a gynostegium. Contrary to this apparent zoophilous floral syndrome, several species of Burmannia were reported to perform self-pollination via cleistogamy. Understanding of reproductive systems in Burmannia is complicated by scarcity of available results of direct observations on pollination process. Here we present data on pollination biology of B. disticha obtained during field investigations in Vietnam followed by laboratory analyses of ecologically important floral traits and the captured flower visitors. We found that the anthetic perianth is open, i.e. the flower is chasmogamous. The flowers are visited by various Diptera, Hymenoptera, Lepidoptera and Orthoptera. Of them, the bumblebees (Bombus burmensis), a bee (Coelioxys sp.) and some lepidopterans were revealed to carry pollen of B. disticha. Based on the amount of carried pollen, insect behavior during the visits and general knowledge on biology of these insect taxa, we concluded that the bumblebees act as the principal pollinators of B. disticha, whereas the lepidopterans are considered as its possible pollinators. We compared the lengths of proboscises of the captured insects to the depth of the floral chamber, and found that only the bumblebees and lepidopterans should be able to reach the nectar. Finally, we estimated the pollen-ovule ratio of B. disticha as 6.84, which is comparable to the ratio known in autogamous angiosperms. Based on its flower organization and pollination mechanism, we consider B. disticha an entomophilous and predominantly xenogamous species. Its gynostegium is likely an adaptation for pollen transfer by insects with long proboscises. At the same time, earlier investigations together with pollen-ovule ratio indicate that B. disticha possesses a labile pollination strategy, and autogamy sometimes occurs. Since Burmannia is one of the few angiosperm genera that comprise both mycoheterotrophic (achlorophyllous) and autotrophic (green) species, our study provides important evidence for reconstructions of ecological and morphological evolutionary pathways in relation to the mode of organic nutrition.

Reproductive Biology and Breeding Systems of Two Opisthopappus Endemic and Endangered Species on the Taihang Mountains.

Opisthopappus is a perennial, endemic herb of the Taihang Mountains in China. Two species of this genus (O. longilobus and O. taihangensis) are important wild genetic resources for Asteraceae; however, their reproductive biology has been lacking until now. This study is the first detailed report on the reproductive biology and breeding systems of two Opisthopappus species. Through field observations, the floral syndromes of O. longilobus and O. taihangensis were found to possess a similar pattern, although O. taihangensis has a relatively larger capitulum, more ray ligules, and disc florets. The flowers of both O. longilobus and O. taihangensis are protandrous, a character that can prevent autogamy at the single-flower level, and insects are required for pollination. Further, brightly ligules, brightly bisexual florets, unique fragrance, and amount of nectar suggest that these species propagate via an entomophilous pollination system. Hymenopteran and Diptera species were observed as the effective pollinators for these two species. The outcrossing index, pollen/ovule ratio and the results of hand pollination indicated that these Opisthopappus species might have a mixed mating system that combines cross-fertilization and partial self-fertilization for O. longilobus and O. taihangensis, outcrossing predominated in the breeding system, while self-pollination played an important role in seed production when insect pollination was unavailable, particularly in a harsh environment, such as the Taihang Mountains cliffs. Meanwhile, O. taihangensis might better adapt to severe surroundings with relatively complex floral syndromes, specifically through the attraction of visiting insects and a high seed set rate. The above results not only provide reference information toward a better understanding of the survival strategies of O. longilobus and O. taihangensis in the Taihang Mountains but also lay a solid foundation for further exploring the molecular mechanisms that underly their adaptation under cliff environments.

Characterizing each step of pollination in Phlox drummondii reveals a single butterfly species predominates the pollinator assemblage.

A central goal of pollination biology is to connect plants with the identity of their pollinator(s). While predictions based on floral syndrome traits are extremely useful, direct observation can reveal further details of a species' pollination biology. The wildflower, Phlox drummondii, has a floral syndrome consistent with Lepidoptera pollination. We test this prediction using empirical data. We observe each step of pollination in P. drummondii. First, we observe 55.5 hours of floral visitation across the species range. We use temporal pollinator exclusion to determine the contribution of diurnal and nocturnal pollination to reproductive output. We then quantify P. drummondii pollen transfer by the dominant floral visitor, Battus philenor. Finally, we test the effect of B. philenor visitation on P. drummondii reproduction by quantifying fruit set following single pollinator visits. B. philenor is the primary pollinator of P. drummondii. Pollination is largely diurnal, and we observe a variety of lepidopteran visitors during this period. However, B. philenor is the most frequent visitor, representing 88.5% of all observed visits. We show that B. philenor is an extremely common visitor and also an effective pollinator by demonstrating that individuals transfer pollen between flowers and that a single visit can elicit fruit set. Our data are consistent with the prediction of lepidopteran pollination and further reveal a single butterfly species, B. philenor, as the primary pollinator. Our study demonstrates the importance of empirical pollinator observations, adds to our understanding of pollination mechanics, and offers a specific case study of butterfly pollination. This article is protected by copyright. All rights reserved.

Pollination systems and nectar rewards in four Andean species of Salvia (Lamiaceae)

Adaptation to the most effective pollinator is often conceived as the primary explanation of widespread convergence in flower phenotypes. However, specialization does not exclude the presence of other floral visitors, which may contribute to plant reproduction. Here we combined observations about pollinators’ visitation rates and effectiveness with nectar secretion dynamics and sugar composition in four Andean Salvia species from Bolivia. The study revealed a wider diversity than expected both in pollination systems and in nectar strategies. While Salvia haenkei Benth. and Salvia stachydifolia Benth. were almost exclusively pollinated by either hummingbirds or bees, respectively, mixed pollination was found in Salvia orbignaei Benth., a species previously described as hummingbird-pollinated. Salvia personata Epling. was exclusively pollinated by syrphid flies. Differences in nectar volume and sugar concentration were found between insect-pollinated species and mixed- or hummingbird-pollinated species. However, the four Salvia species displayed different strategies regarding nectar sugar composition, with sucrose-rich nectar in Salvia orbignaei, glucose-rich nectar in Salvia haenkei and Salvia stachydifolia, and glucose-rich nectar lacking fructose in Salvia personata, suggesting an adaptation to syrphid fly pollination. Our results provide a clearer picture of floral trait evolution in Salvia and highlight the contribution of some pollinators different from those expected according to the floral syndromes.

Sources of Variation in Reciprocal Herkogamy in the Distyly Floral Syndrome of Linum tenue (Linaceae)

Premise of research. Distyly is a floral polymorphism involving reciprocal herkogamy shaped by selection for pollen transfer efficiency. The variation of the floral organs involved in pollen transfer can be individually affected by environmental and genetic sources of variance, but the organ development will be canalized to minimize reciprocal inaccuracy between anthers and stigmas, as this is the focus of selection.Methodology. We measured floral organ and cell length of both morphs of distylous Linum tenue (Linaceae) at different developmental stages of field- and glasshouse-grown plants. We analyzed the results to measure reciprocal inaccuracy and identify sources of variance.Pivotal results. Flowers from the field were larger than those from the glasshouse owing to both environmental and genetic (population) factors. Pistil and stamen length in adult flowers correlated with flower size, but reciprocal herkogamy was mostly invariant to the size of individual floral organs. The length of short floral organs showed greater maladaptive bias, while the length of tall organs showed greater imprecision. During development, the pistils of pin flowers grew at a faster rate than those of thrum flowers, mostly owing to cell elongation, while cell division was more important for male organ height.Conclusions. Distyly in L. tenue involves the interaction of multiple coordinated developmental and environmental mechanisms, leading to limited but predictable patterns of variance in the expression of reciprocal herkogamy.

Are the floral morphology and anatomy of Galphimia australis, an atypical neotropical Malpighiaceae, associated to a new pollination syndrome?

The flowers of the species of Malpighiaceae in the Neotropical Region are relatively uniform in their morphology due to their dependence on oil-collecting bees as their main pollinators. However, many species of the genus Galphimia seem to have acquired a different floral syndrome, lacking markedly zygomorphic flowers and developed elaiophores in the calyx. Likewise, these species present anthers with great development, probably in response to the selection of pollinators that collect pollen. Galphimia australis incorporated some of these traits but also retained some residual characteristics typical of species pollinated by oil bees. This leads to many questions on how these flowers ensure their pollination. Inquiring about the reduction or modification of these characteristics allows us to understand how G. australis achieves a different pollination syndrome. In this research, we carry out a detailed morphological and anatomical study of the flowers and pollen grain devolvement of G. australis and floral visitors were observed and captured. Results were analyzed in order to determine how this species changed from the oil-floral syndrome, typical of neotropical Malpighiaceae, to one syndrome with pollen as the main reward.

Phylogenetic Analyses of Some Key Genes Provide Information on Pollinator Attraction in Solanaceae.

Floral syndromes are known by the conserved morphological traits in flowers associated with pollinator attraction, such as corolla shape and color, aroma emission and composition, and rewards, especially the nectar volume and sugar concentration. Here, we employed a phylogenetic approach to investigate sequences of genes enrolled in the biosynthetic pathways responsible for some phenotypes that are attractive to pollinators in Solanaceae genomes. We included genes involved in visible color, UV-light response, scent emission, and nectar production to test the hypothesis that these essential genes have evolved by convergence under pollinator selection. Our results refuted this hypothesis as all four studied genes recovered the species' phylogenetic relationships, even though some sites were positively selected. We found differences in protein motifs among genera in Solanaceae that were not necessarily associated with the same floral syndrome. Although it has had a crucial role in plant diversification, the plant-pollinator interaction is complex and still needs further investigation, with genes evolving not only under the influence of pollinators, but by the sum of several evolutionary forces along the speciation process in Solanaceae.

Genomic evidence supports the genetic convergence of a supergene controlling the distylous floral syndrome.

Heterostyly, a plant sexual polymorphism controlled by the S-locus supergene, has evolved numerous times among angiosperm lineages and represents a classic example of convergent evolution in form and function. Determining whether underlying molecular convergence occurs could provide insights on constraints to floral evolution. Here, we investigated S-locus genes in distylous Gelsemium (Gelsemiaceae) to determine whether there is evidence of molecular convergence with unrelated distylous species. We used several approaches, including anatomical measurements of sex-organ development and transcriptome and whole-genome sequencing, to identify components of the S-locus supergene. We also performed evolutionary analysis with candidate S-locus genes and compared them with those reported in Primula and Turnera. The candidate S-locus supergene of Gelsemium contained four genes, of which three appear to have originated from gene duplication events within Gelsemiaceae. The style-length genes GeCYP in Gelsemium and CYP734A50 in Primula likely arose from duplication of the same gene, CYP734A1. Three out of four S-locus genes in Gelsemium elegans were hemizygous, as previously reported in Primula and Turnera. We provide genomic evidence on the genetic convergence of the supergene underlying distyly among distantly related angiosperm lineages and help to illuminate the genetic architecture involved in the evolution of heterostyly.

Papilio butterfly vs. hawkmoth pollination explains floral syndrome dichotomy in a clade of Lilium

Abstract Pollination niche shifts can drive remarkable floral divergence between closely related plant species. The Leucolirion clade of Lilium contains species with either tepal-recurved or trumpet-shaped flowers. The tepal-recurved flowers are bright orange and might be pollinated by butterflies and/or birds. The trumpet-shaped flowers are mostly pale and strongly fragrant and might permit visitation by a variety of hawkmoths. Lilium leucanthum has trumpet-shaped flowers, and some populations of this species show dark coloration on the floral outer surface, suggesting pollination by mammals. We identified pollinators and examined the dependence of reproduction on pollinators by floral visitor observations, pollen load analysis and pollination experiments. We also analysed floral traits to contrast the two floral syndromes involving different lepidopteran groups. The tepal-recurved lilies are specialized on a group of Papilio butterflies for pollination with pollen predominantly attached to the hindwings. The trumpet-shaped flowers are almost exclusively pollinated by hawkmoths, including diverse species with proboscises of different lengths. No mammal visitation was found to the populations of L. leucanthum with dark outer surfaces of flowers. Self-incompatibility prevails throughout the clade, including the populations in which pollinators were scarce. The butterfly- and hawkmoth-pollinated species display contrasting floral syndromes. Our findings confirmed that the dichotomy in floral syndrome in the Leucolirion clade is associated with Papilio butterfly vs. hawkmoth pollination, whereas intraspecific variation in colour of the floral outer surface of L. leucanthum many need a non-pollinator explanation.

ATLANTIC POLLINATION: a data set of flowers and interaction with nectar-feeding vertebrates from the Atlantic Forest.

Flowering plant species and their nectar-feeding vertebrates exemplify some of the most remarkable biotic interactions in the Neotropics. In the Brazilian Atlantic Forest, several species of birds (especially hummingbirds), bats, and non-flying mammals, as well as one lizard feed on nectar, often act as pollinators and contribute to seed output of flowering plants. We present a dataset containing information on flowering plants visited by nectar-feeding vertebrates and sampled at 166 localities in the Brazilian Atlantic Forest. This dataset provides information on 1902 unique interactions among 515 species of flowering plants and 129 species of potential vertebrate pollinators and the patterns of species diversity across latitudes. All plant-vertebrate interactions compiled were recorded through direct observations of visits, and no inferences of pollinators based on floral syndromes were included. We also provide information on the most common plant traits used to understand the interactions between flowers and nectar-feeding vertebrates: plant growth form, corolla length, rate of nectar production per hour in bagged flowers, nectar concentration, flower color and shape, time of anthesis, presence or absence of perceptible fragrance by human, and flowering phenology as well as the plant's threat status by International Union for Conservation of Nature (IUCN) classification. For the vertebrates, status of threat by IUCN classification, body mass, bill or rostrum size are provided. Information on the frequency of visits and pollen deposition on the vertebrate's body is provided from the original source when available. The highest number of unique interactions is recorded for birds (1771) followed by bats (110). For plants, Bromeliaceae contains the highest number of unique interactions (606), followed by Fabaceae (242) and Gesneriaceae (104). It is evident that there was geographical bias of the studies throughout the southeast of the Brazilian Atlantic Forest and that most effort was directed to flower-hummingbird interactions. However, it reflects a worldwide tendency of more plants interacting with birds compared with other vertebrate species. The lack of similar protocols among studies to collect basic data limits the comparisons among areas and generalizations. Nevertheless, this dataset represents a notable effort to organize and highlight the importance of vertebrate pollinators in this hotspot of biodiversity on Earth and represents the data currently available. No copyright or proprietary restrictions are associated with the use of this data set. Please cite this data paper when the data are used in publications or scientific events.

Pollination biology of Erica aristata: First confirmation of long-proboscid fly-pollination in the Ericaceae

Long-proboscid fly (LPF) pollination has been recorded in multiple plant lineages in South Africa. However in the large and morphologically diverse genus Erica, evidence for LPF pollination is limited to predictions based upon floral syndromes as well as anecdotal observation and limited citizen science records. Here we use breeding system experiments, pollinator exclusion, remote camera traps, spectral analysis and field observation in the Klein River Mountains, Western Cape Province, South Africa, to demonstrate this mode of pollination in the range-restricted taxon Erica aristata. This species has long narrow corolla tubes with narrow opening and contrasting white and crimson pink petals. Flowers were visited and pollinated exclusively by one long-proboscid fly species, Prosoeca rubicunda (Nemestrinidae) over four years at this study site. Breeding experiments showed that E. aristata is not self-compatible and pollinator exclusion experiments indicate that pollinator visits were required for seed-set. Low nectar volume and moderately high nectar sugar concentration were consistent with other long-proboscid fly-pollinated plant species in the Cape. This study represents the first confirmed instance of long-proboscid fly-pollination in the genus Erica.

Complex interactions underlie the correlated evolution of floral traits and their association with pollinators in a clade with diverse pollination systems.

Natural selection by pollinators is an important factor in the morphological diversity and adaptive radiation of flowering plants. Selection by similar pollinators in unrelated plants leads to convergence in floral morphology, or "floral syndromes." Previous investigations into floral syndromes have mostly studied relatively small and/or simple systems, emphasizing vertebrate pollination. Despite the importance of multiple floral traits in plant-pollinator interactions, these studies have examined few quantitative traits, so their co-variation and phenotypic integration have been underexplored. To gain better insights into pollinator-trait dynamics, we investigate the model system of the phlox family (Polemoniaceae), a clade of ∼400 species pollinated by a diversity of vectors. Using a comprehensive phylogeny and large dataset of traits and observations of pollinators, we reconstruct ancestral pollination system, accounting for the temporal history of pollinators. We conduct phylogenetically controlled analyses of trait co-variation and association with pollinators, integrating many analyses over phylogenetic uncertainty. Pollinator shifts are more heterogeneous than previously hypothesized. The evolution of floral traits is partially constrained by phylogenetic history and trait co-variation, but traits are convergent and differences are associated with different pollinators. Trait shifts are usually gradual, rather than rapid, suggesting complex genetic and ecological interactions of flowers at macroevolutionary scales.

Comparing the reproductive biological characteristics of the alien invasive Coreopsis lanceolata to those of the non‐invasive alien congener Coreopsis tinctoria

AbstractIt is important to determine the characteristics associated with the success of alien species. However, there is no universal syndrome of invasion reproductive characteristics to explain the success of invasiveness has not been identified. Comparative studies on congeneric successful or non‐successful alien species are beneficial for revealing the drivers of invasion success and predicting future distributions. Reproductive biological characteristics, including the mating system, phenology of flowering, floral syndrome, pollination biology and seed germination have been investigated in the invasive Coreopsis lanceolata and non‐successful congener alien species Coreopsis tinctoria. The results revealed that C. lanceolata significantly attracted insect visitors by 11.67 times more than its congener, and the corolla density of C. lanceolata was positively correlated with the number of visiting insects. The high attraction of local insect bees Apis cerana guarantees the reproductive success and high seed production of C. lanceolata. Nevertheless, there was no versatile mating system, because its congener non‐successful alien species C. lanceolata still successfully invaded due to the combination strategies of self‐compatibility and presence of rhizomes. Furthermore, the ability of seed germination of C. lanceolata was lower than that of C. tinctoria, especially under drought and Al3+ stress, suggesting that germination performance can serve as a reference indicator. However, this was not an absolute trait for invasiveness. Hence, these germination traits might slow down the invasiveness of C. lanceolata in south China. These present findings highlight that the combination of self‐incompatibility and rhizomes should be given attention in the risk assessment protocols for plant invasiveness.