Diversity Of Flowering Plants Research Articles

Repeated shifts out of tropical climates preceded by whole genome duplication.

While flowering plants have diversified in virtually every terrestrial clime, climate constrains the distribution of individual lineages. Overcoming climatic constraints may be associated with diverse evolutionary phenomena including whole genome duplication (WGD), gene-tree conflict, and life-history changes. Climatic shifts may also have facilitated increases in flowering plant diversification rates. We investigate climatic shifts in the flowering plant order Ericales, which consists of c. 14 000 species with diverse climatic tolerances. We estimate phylogenetic trees from transcriptomic data, 64 chloroplast loci, and Angiosperms353 nuclear loci that, respectively, incorporate 147, 4508, and 2870 Ericales species. We use these phylogenetic trees to analyse how climatic shifts are associated with WGD, gene-tree conflict, life-history, and diversification rates. Early branches in the phylogenetic trees are extremely short, and have high levels of gene-tree conflict and at least one WGD. On lineages descended from these early branches, there is a significant association between climatic shifts (primarily out of tropical climates), further WGDs, and life-history. Extremely short early branches, and their associated gene-tree conflict and WGDs, appear to underpin the explosive origin of numerous species rich Ericales clades. The evolution of diverse climatic tolerances in these species rich clades is tightly associated with WGD and life-history.

A massive community-science dataset reveals convergent evolution of delayed flowering phenology in North American red-flowering plants.

The radiation of angiosperms is marked by a phenomenal diversity of floral size, shape, color, scent, and reward. Through hundreds of years of documentation and quantification, scientists have sought to make sense of this variation by defining pollination syndromes. These syndromes are the convergent evolution of common suits of floral traits across distantly related species that have evolved by selection to optimize pollination strategies. The availability of community-science datasets provides an opportunity to develop new tools and to examine new traits that may help further characterize broad patterns of flowering plant diversity. Here we test the hypothesis that flowering phenology can also be a pollination syndrome trait. We generate a novel flower color dataset by using GPT-4 with Vision (GPT-4V) to assign flower color to 11,729 North American species. We map these colors to 1,674,908 community-scientist observations of flowering plants to investigate patterns of phenology. We demonstrate constrained flowering time in the eastern United States for plants with red or orange flowers relative to plants with flowers of other colors. Red-and orange-colored flowers are often characteristic of the "hummingbird" pollination syndrome; importantly, the onset of red and orange flowers corresponds to the arrival of migratory hummingbirds. Our results suggest that the hummingbird pollination syndrome can include flowering phenology and reveal an opportunity to expand the suite of traits included in pollination syndromes. Our methods demonstrate an effective pipeline for leveraging enormous amounts of community science data by using artificial intelligence to extract information about patterns of trait variation.

Integrated vegetation management within electrical transmission landscapes promotes floral resource and flower-visiting insect diversity.

Electrical transmission rights-of-way are ubiquitous and critical infrastructure across the landscape. Active vegetation management of these rights-of-way, a necessity to deliver electricity more safely, maintains these landscape features as stages of early successional habitat, a rarity in many regions, making these areas viable movement corridors for many taxa. The goals of this study were to (i) evaluate the effects of different electrical transmission landscape management practices on flowering plant and flower-visiting insect diversity parameters and (ii) generate conservation management inferences for these landscapes. In this study we tested the impact of three vegetation management levels across 18 electrical transmission sites. We evaluated the effects of treatment on bloom abundance and species richness as well as flower-visiting insect abundance and family richness. We identified 76541 flowers/inflorescences across 456 transects, including 188 species in 56 plant families. Additionally, we obtained data on 11361 flower-visitoring insects representing 33 families from 2376 pan trap sets. High vegetation management favored the reduction of coarse woody debris in the sites and harbored the highest level of abundance and richness of both floral resources and flower-visiting insects. We discuss that we can align social and ecological values of rights-of-way, ensuring their sustainability by applying regular and targeted integrated vegetation management. Thus, we can use rights-of-way landscapes not only as an effective management strategy for the delivery of essential human services, but also to provide conservation benefits for wild pollinators.

Bee diversity and pollination services improve with revegetation effort

AbstractHabitat loss is causing declines in native bees and reducing pollination services. Revegetation can be used to reverse these declines, and this restoration technique attracts growing efforts and resources. However, how the quality of revegetation affects native bee abundance, diversity and their pollination services is not well understood, and this limits opportunities to improve revegetation outcomes. To assess this gap, we surveyed floral and bee diversity in revegetated landscapes ranging in habitat quality, and compared these among each other and to remnant habitat and cleared areas. We also measured pollination services using two native phytometer species, which can be pollinated by native bees only, or by both native and introduced honey bees (Apis mellifera). We found that bee diversity and richness were higher within treatments that were higher in floral diversity. In addition, while pollination services provided by honey bees were uniform across treatments, remnant vegetation supported greater pollination services to the plant species pollinated by native bees only. These results indicate that higher quality revegetation characterized by the establishment of a more diverse set of plant species, has the potential to restore native bee diversity and associated pollination services. However, for the plant species investigated, restoration of pollination services had not occurred and might require more time. These results suggest preserving remnant vegetation should be the highest priority conservation action, and that restoration practitioners and landowners wishing to support landscape‐level bee diversity and pollination services, should aim for revegetation using high flowering plant diversity.

Flowering Plant Diversity of Differentially Disturbed Region of Terai Sal (Shorea robusta) Forest in Eastern Nepal

Terai Sal (Shorea robusta C.F.Gaertn.) forest, characteristic forest of lowland of Nepal, faces direct and indirect impacts from various anthropogenic activities. The present work aimed to study and document the flowering plant diversity within differentially disturbed sites of Charali Sal forest. Additionally, we accessed the habitat condition, analyzed the invasion status and prioritize the threats faced by the plant communities and recommended ways to mitigate the prevalent threats. We employed purposive sampling technique to sample the forest areas and nested plot design for vegetation sampling. Thirty sample plots, each measuring 10 m × 10 m, were established on two differentially disturbed sites (disturbed and undisturbed) of Charali Sal forest. A total of 111 flowering plant species belonging to 39 families were documented in the sampling sites, with 90 total species (89 identified) in disturbed sites and 86 species (80 identified) in undisturbed sites. Although the disturbed sites contained higher number of flowering plants, the diversity indices (Simpson and Shannon-wiener’s) indicated higher diversity on undisturbed site. Disturbed site exhibited higher human encroachment and higher invasion of alien species compared to undisturbed site. Specific habitat management plans should be devised for the control and eradication of invasive species from the Charali Sal forest. We highly recommend to delimit a buffer zone all around the forest perimeter to regulate local access inside the forest. Collecting and harvesting various forest products should be restricted to the buffer zone, while the inner forest areas should be under careful and strict management. Implementing these strict managemental strategies would be challenging, but it is crucial for preserving the natural integrity of the forest.

Holistic wild bee management in urban spaces

Projects promoting bees in urban areas are initiated in cities around the world but evidence-based conservation concepts at a city-wide scale are scarce. We developed a holistic approach for assessment of bee and flowering plant diversity in a medium-sized city. In addition to standard mapping approaches in bee hotspots, we initiated citizen science projects for participative urban bee research to be able to collect comprehensive bee data across the entire city. We identified 22 hotspots of bee diversity, analyzed connectivity between those hotspots and evaluated the impact of flower patches planted in collaboration with the municipal gardens department as stepping stones for oligolectic bee species throughout the city. Participation by urban citizens in bee identification trainings was high (c. 630 persons) but their subsequent contribution through observation reports was relatively low (1,165 records by 140 observers). However, we identified a total of 139 bee taxa, seven of them only discovered by citizen scientists. Total species richness was higher in extensively managed orchards than in semi-natural and wasteland areas. Half of the stepping stone flower patches were occupied by the target oligolectic bee species in the year of planting. After 3 years, all but two species could be confirmed. We suggest a 5-step concept for bee management in cities: (1) identification of bee hotspots combined with standardized surveys, especially of rare species; (2) training of citizen scientists at two different levels for comprehensive surveys in all parts of the city: (a) half-day introductions to wild bee diversity, ecology and conservation in order to create more awareness and (b) 2-weeks workshops for in-depth training of a small number of dedicated citizen scientists; (3) extensive management of existing habitats and special conservation programs for very rare species; (4) creation of high-value habitats which take into account the varied resource needs of bees within flight ranges of only a few hundred meters; (5) creation of stepping stone habitats as floral and nesting resources, integrating educative and participative aspects.

Diversification of flowering plants in space and time

The rapid diversification and high species richness of flowering plants is regarded as ‘Darwin’s second abominable mystery’. Today the global spatiotemporal pattern of plant diversification remains elusive. Using a newly generated genus-level phylogeny and global distribution data for 14,244 flowering plant genera, we describe the diversification dynamics of angiosperms through space and time. Our analyses show that diversification rates increased throughout the early Cretaceous and then slightly decreased or remained mostly stable until the end of the Cretaceous–Paleogene mass extinction event 66 million years ago. After that, diversification rates increased again towards the present. Younger genera with high diversification rates dominate temperate and dryland regions, whereas old genera with low diversification dominate the tropics. This leads to a negative correlation between spatial patterns of diversification and genus diversity. Our findings suggest that global changes since the Cenozoic shaped the patterns of flowering plant diversity and support an emerging consensus that diversification rates are higher outside the tropics.

The Remarkable Diversity of Parasitic Flowering Plants in Colombia

Parasitic plants have evolved independently in 12 Angiosperm orders. Nine of them (Boraginales, Cucurbitales, Ericales, Lamiales, Laurales, Malvales, Santalales, Solanales, and Zygophyllales) are represented in Colombia by 17 families, 44 genera and 246 species, including facultative (37) and obligate (187) hemiparasites, holoexoparasites (19) and holoendoparasites (3). Cladocolea coriacea (Loranthaceae) is reported for the first time in Colombia. One genus (Sanguisuga, Cytinaceae) and 69 species (28.04%) are endemic to the country. Endemism decreases with elevation, ranging from 26 species (37.68%) below 1000 m, to one species (1.44%) above 4000 m. Speciation in Aetanthus, Psittacanthus and Tristerix (Loranthaceae), Dendrophthora and Phoradendron (Viscaceae), and Castilleja and Neobartsia (Orobanchaceae) was likely prompted by the Andean uplift. The highest number of species (169) are found in the Andean Region, whereas the Orinoco Region contains the lowest number (29). Dry forests and thickets, and coastal vegetation of the Caribbean Region are the preferred ecosystems for Krameria (Krameriaceae), Sanguisuga, Acanthosyris (Cervantesiaceae), Maracanthus (Loranthaceae), Ximenia (Ximeniaceae), Lennoa (Ehretiaceae), and Anisantherina (Orobanchaceae). Orobanche minor, recently introduced to the country, is the only potential weed for crops between 2500 and 3200 m in the Eastern Cordillera. Convergent lifeforms include: the obligate, twining stem holoparasitic Cassytha (Lauraceae) and Cuscuta (Convolvulaceae); the root holoexoparasitic Sanguisuga, Mitrastemon (Mitrastemonaceae), all Balanophoraceae, and Lennoa; and the root obligate hemiparasitic Krameria, Gaiadendron (Loranthaceae), and all Cervantesiaceae, Opiliaceae, Schoepfiaceae, Strombosiaceae and Ximeniaceae. Holoendoparasitism occurs only in Apodanthaceae, whereas root facultative hemiparasitism is restricted to the Orobanchaceae.

Forest habitats and plant communities strongly predicts Megachilidae bee biodiversity.

Megachilidae is one of the United States' most diverse bee families, with 667 described species in 19 genera. Unlike other bee families, which are primarily ground nesters, most megachilid bees require biotic cavities for nesting (i.e., wood, pithy stems, etc.). For this group, the availability of woody-plant species may be as important as nectar/pollen resources in maintaining populations. We studied Megachilidae biodiversity in the continental United States. We confirmed that the highest species richness of Megachilidae was in the southwestern United States. We examined the relationship between species richness and climate, land cover, tree species richness, and flowering plant diversity. When examining environmental predictors across the conterminous United States, we found that forested habitats, but not tree diversity, strongly predicted Megachilidae richness. Additionally, Megachilidae richness was highest in areas with high temperature and low precipitation, however this was not linearly correlated and strongly positively correlated with flowering plant diversity. Our research suggests that the availability of nesting substrate (forested habitats), and not only flowering plants, is particularly important for these cavity-nesting species. Since trees and forested areas are particularly susceptible to climate change, including effects of drought, fire, and infestations, nesting substrates could become a potential limiting resource for Megachilidae populations.

Arthropods discovered on refugio flowering plants in Mangifera indica plantation

Abstract. Windriyanti W, Rahmadhini N, Fernando I, Kusuma RM. 2023. Arthropods discovered on refugio flowering plants in Mangifera indica plantation. Biodiversitas 24: 4747-4754. The diversity of Refugio flowering plants with different ways of flowering phenology provides alternative food sources for arthropods. Insects are the largest class of arthropods, most of which are ecological services that function as natural enemies and pollinators. Insects require an energy source over a long-term period to promote a stable and healthy population. The use of flowering plants as refugia can maximize the role of insects as ecological services in agroecosystems by providing natural enemies and pollinators with a source of food and shelter. The refugia plants used in this study were sunflowers (Helianthus annuus), king’s salad (Cosmos caudatus), Peruvian zinnia (Zinnia peruviana), Tridax procumbens (Asteraceae), and Alternanthera sessilis (Amaranthaceae) with hedgerow and insectary bank planting patterns. Data collection and periodic direct observation (scan sampling) were conducted by transects. Observed parameters included species composition and population of arthropods in two different agro-systems, monoculture and polyculture. Identification results showed 8 orders, including 44 morphospecies, belonging to 25 families. Arthropod abundance in the on-season of the refugia was found in 1422 individuals. Ecological engineering is a habitat manipulation technology using refugia plants that has increased the composition and population of natural enemy insects and pollinators.

Diversity of early flowering plants of the Ulytau mountains (Central Kazakhstan)

Early flowering plants (ephemers and ephemeroids) are an important component of the biosystem of steppes and deserts. These species form perennial pasture communities, for early grazing. The present work was conducted to evaluate the floristic checklist and ecological uniqueness of early flowering plants of Central Kazakhstan, in the forest-steppe regions of Em-Bulak region and Edige mountains, during 2021 and 2022. A total of 26 species of ephemers and ephemeroids were recorded, which belong to 16 families: Liliaceae – 3 species, Asteraceae – 3 species, Ranunculaceae – 3 species, Rosaceae – 3 species, Brassicaceae – 2 species, Boraginaceae – 2 species, the other families are represented by one species. According to ecomorphological characteristics: 8 species (31%) belong to the xerophyte group, 6 (23%) to the xeromesophyte group, 7 (27%) to the mesoxerophyte group and 5 (19%) to the mesophyte group. Also, as a result of our research we found two species of plants which are included in the Red Book of the Republic of Kazakhstan – Pulsatilla patens (L.) Mill. and Tulipa patens Agardh. ex Schult. f. The data obtained can be used for environmental monitoring and issues of rational nature management of wild plants of Central Kazakhstan.

Genomic asymmetry of the Brassica napus seed: epigenetic contributions of DNA methylation and small RNAs to subgenome bias.

Polyploidy is a persistent phenomenon in angiosperm genome evolution that is hypothesized to have contributed to the diversity of extant flowering plants. Brassica napus, one of the world's most important angiosperm oilseed species, originated from the interspecific hybridization of Brassica rapa (An ) and Brassica oleracea (Cn ). While the trends of genome dominance in transcriptomics are beginning to emerge, less is known about the epigenetic and small RNA landscapes in polyploids during reproductive development. The seed is the pivotal developmental transition into the new sporophytic generation, and experiences substantial epigenetic modifications over time. Here, we investigated the prevalence of bias in the contexts of DNA methylation and small interfering (si)RNA profiles in both subgenomes (An and Cn ), as well as the ancestral fractionated genomes across B. napus seed development. We report ubiquitous Cn subgenome bias of siRNA expression and cytosine methylation, with DNA methylation being particularly abundant on gene promoters in the Cn subgenome. Further, we provide evidence that siRNA transcriptional patterns were conserved within the ancestral triplicated subgenomes of B. napus, but not across the An and Cn subgenomes. We discuss how methylation patterns in the B. napus seed relate to genes, promoter regions, siRNA loci and transposable elements through the lens of genome fractionation and polyploidization. Taken together we provide evidence for epigenetic regulation selectively silencing the Cn subgenome during seed development, and explore the impact of genome fractionation on the epigenetic components of the B. napus seed.

High species turnover and unique plant-pollinator interactions make a hyperdiverse mountain.

We studied α- and β-diversity of pollinators, flowering plants and plant-pollinator interactions along the altitudinal gradient of Mt. Olympus, a legendary mountain and biodiversity hotspot in Central Greece. We explored 10 study sites located on the north-eastern slope of the mountain, from 327 to 2596 m a.s.l. Insect surveys were conducted once a month using hand netting (years 2013, 2014 and 2016), and they were combined with recordings of flowering plant diversity (species richness and flower cover). We then calculated α- and β-diversity of pollinators, plants in flower and plant-pollinator interactions, and explored their demographic response along the altitudinal gradient. Alpha diversity of pollinators, plants and plant-pollinator interactions were altitude dependent; α-diversity of all pollinators, bees, non-bumblebee bees, bee flies and butterflies showed linear declines with altitude, whereas those of hoverflies and bumblebees showed unimodal patterns. Beta diversity and its turnover component of all pollinators, hoverflies, bees, bumblebees, non-bumblebee bees, butterflies and plants showed linear increases, whereas those of bee flies and of plant-pollinator interactions varied independently from the pairwise altitudinal difference. The high dissimilarity and uniqueness of pollination networks, which is probably a result of the high biodiversity and endemism of Mt. Olympus, is driven by species turnover and the formation of new interactions between new species. Contrasting to the monotonic decline of the remaining groups, the unimodal patterns of hoverfly and bumblebee α-diversity are probably the effect of a higher tolerance of these groups to high-altitude environmental conditions. Our findings highlight that the high turnover of species and of pollination interactions along the altitudinal gradient are the mainstay of hyperdiverse mountains, a fact that conveys important historical, ecological and conservational implications.

Analysis of Citizen Science-Based Flowering Plant Diversity Worksheet Development to Improve Students’ Critical Thinking Ability

The purpose of this study was to assess the feasibility of the developed Citizen Science-Based Flowering Plant Diversity Worksheet as well as the enhancement of students' critical thinking abilities. This was a pre-experiment with a pretest-posttest design with one group. Validator employed a four-scale validation sheet to assess the feasibility of the Citizen Science-Based Flowering Plant Diversity Worksheet based on competency, practical, knowledge construction, and the appearance of critical thinking ability. Five critical thinking ability indicators were tested: interpretation, analysis, explanation, evaluation, and inference. These indications were tested in 104 10th grade students through a critical thinking ability test before and after studying with the Citizen Science-Based Flowering Plant Diversity worksheet. Descriptive statistics were used to analyze the data. The Citizen Science-Based Flowering Plant Diversity Worksheet was found feasible (95.12%) and students' critical thinking abilities increased moderately (N-Gain = 0.56). The most notable development in critical thinking ability was in interpretation ability, while inference ability improved the least. As a result, the Citizen Science-Based Flowering Plant Diversity Worksheet may be inferred to be quite effective in improving students' critical thinking abilities.

Indian rock outcrops: review of flowering plant diversity, adaptations, floristic composition and endemism

Indian rock outcrops: review of flowering plant diversity, adaptations, floristic composition and endemism

A comprehensive evaluation of flowering plant diversity and conservation priority for national park planning in China

Establishment of a national park protection system in China, including the latest target proposed to protect at least 30% of the land area, calls for a comprehensive exploration of conservation priorities incorporating multiple diversity facets. We herein evaluate the spatial distribution of Chinese flowering plants from the perspectives of richness, uniqueness, vulnerability, and evolutionary history, by integrating three mega-phylogenies and comprehensive distribution data. We detect significantly high consistency among hotspots of different diversity measures for Chinese flowering plants, suggesting that multiple facets of evolutionary diversity are concentrically distributed in China. Affording legal protection to these areas is expected to maximize positive conservation outcomes. We propose two integrative diversity indices by incorporating three richness-based and three phylogeny-based measures, respectively. Both methods identify areas with high species richness, but the integrative phylogeny-based index also locates key areas with ancient and unique evolutionary histories (e.g., Ailao-Wuliang Mts, Dabie Mts, Hainan rainforest, Karst area of Yunnan-Guizhou-Guangxi, Nanling Mts, and southeast coastal regions). Of all the diversity indices explored, phylogenetic endemism maximizes the incidental protection of other indices in most cases, emphasizing its significance for conservation planning. Finally, 42 priority areas are identified by combining the 5%-criterion hotspots of two integrative indices and the minimum area to protect all threatened species analyzed. These priorities cover only 13.3% of China's land area, but host 97.1% of species richness (23,394/24,095), 96.5% of endemic species (11,841/12,274), 100% of threatened species (2,613/2,613), and 99.3% of phylogenetic diversity for flowering plants involved in this study. These frameworks provide a solid scientific basis for national park planning in China.

An Annotated Checklist to the Alpine and Sub Alpine Flowering Plant Diversity of Dzongri-Goecha La Area, West Sikkim, India

A total of 254 plant species belonging to 151 genera and 47 families were collected from alpine and subalpine regions of Dzongri Goecha La area. Of the total species collected, the first ten dominating family contributed more than 52.75% while the first ten dominating genera contributed 37.74 % of total genera of the studied area. 22 taxa have been reported new to region during the study.

Kentsel Arıcılık Kuralları ve Zorlukları

Honey bee (Apis mellifera L.) is the most widely grown insect species in the world and is very important both economically and ecologically. Recently, keeping honey bees in urban areas is becoming also increasingly pop-ular around the world due to many reasons such as the presence of more flowering plant diversity in parks, gardens and other green areas of urban areas compared to rural areas, and the lower risk of both pesticides and parasites in urban areas. Today, honey bee colonies are found everywhere, from the roofs and terraces of buildings in city cores to suburban backyards. While urban beekeeping practices are similar to those in suburban and rural areas, in densely populated urban environment, urban beekeepers face many challenges such as hive placement, colony management, preventing of swarming and robbing, provision of water source, human/bee interaction and bee poo. Urban beekeeping creates new concerns. Increased honey bee colony densities in cities might have negative effects on wild bee species by transmitting parasites and pathogens and by competing for nectar and pollen resources in addition to honey bee colony productivity. There is, therefore, a need for good urban beekeeping regulations to maximize the benefits while minimizing the risks. In this review, current regulations regarding urban beekeeping were addressed and some suggestions were presented to reduce complaints from city dwellers.

The effects of changes in flowering plant composition caused by nitrogen and phosphorus enrichment on plant-pollinator interactions in a Tibetan alpine grassland.

Soil eutrophication from atmospheric deposition and fertilization threatens biodiversity and the functioning of terrestrial ecosystems worldwide. Increases in soil nitrogen (N) and phosphorus (P) content can alter the biomass and structure of plant communities in grassland ecosystems; however, the impact of these changes on plant–pollinator interactions is not yet clear. In this study, we tested how changes in flowering plant diversity and composition due to N and P enrichment affected pollinator communities and pollination interactions. Our experiments, conducted in a Tibetan alpine grassland, included four fertilization treatments: N (10 g N m–2 year–1), P (5 g P m–2 year–1), a combination of N and P (N + P), and control. We found that changes in flowering plant composition and diversity under the N and P treatments did not alter the pollinator richness or abundance. The N and P treatments also had limited effects on the plant–pollinator interactions, including the interaction numbers, visit numbers, plant and pollinator species dissimilarity, plant–pollinator interaction dissimilarity, average number of pollinator species attracted by each plant species (vulnerability), and average number of plant species visited by each pollinator species (generality). However, the N + P treatment increased the species and interaction dissimilarity in flowering plant and pollinator communities and decreased the generality in plant–pollinator interactions. These data highlight that changes in flowering plants caused by N + P enrichment alter pollination interactions between flowering plants and pollinators. Owing to changes in flowering plant communities, the plant–pollinator interactions could be sensitive to the changing environment in alpine regions.

Small genetic steps lead to mechanical isolation in hummingbird-pollinated gingers.

Interactions with pollinators are a potent source of natural selection driving the spectacular array of flowering plant diversity on Earth (Kay & Sargent, 2009; Van der Niet et al., 2014). Floral traits play a central role in this process: reliable and effective pollination by animal pollinators depends on complex floral features, including traits that determine pollinator attraction and reward, as well as the mechanics of pollen transfer. Pollinators specify mating events between individuals, and thus differences in flowers have the potential to generate reproductive isolating barriers (floral isolation). A compelling case of floral isolation comes from spiral gingers (Costus), where hummingbird-adapted species have evolved distinct pollen placement strategies (on the bills vs. foreheads of pollinators) due to differences in flower shape and the arrangements of flower parts. This difference in pollen placement causes a mechanical barrier to cross-pollination. In this issue of Molecular Ecology, Kay and Surget-Groba (2022) dissect the genetic basis of these floral differences using a quantitative trait locus (QTL) mapping approach. They find small-effect QTLs that influence multiple correlated traits and allelic effects that suggest a history of directional selection. Their results indicate mechanical isolation reflects adaptive divergence that has built up piecemeal over time.