An estimated 20,000 angiosperm species conceal pollen inside tubular poricidal anthers or within modified petals. A bee releases pollen by vibrating its thorax and transferring the force through its mandibles while biting the flower. While the floral morphology of buzz-pollinated plants is diverse, the behaviors, dimensions and guilds of buzzing bees are limited. Floral modifications should reflect the relative sizes of their co-adapted pollinator species but we do not know what drives these size associations. We show that the optimal excitation point in the vibration system of bumblebee-pollinated louseworts (Pedicularis) occurs precisely where bumblebees bite these flowers. This leads to trait matching between a bumblebee’s individual body length and the beak length of the flowers of each lousewort species. As bumblebees do not visit flowers with beaks (galea) longer than their bodies it guarantees they bite the optimal excitation point for pollen discharge.

Complete plastid genomes have recently been proposed as ”super-barcodes” for genetic identification and delineation in plants, for which standard DNA barcodes may fail. However, relatively few studies have fully considered the genetic mechanisms inherent to the taxonomic complexity of specious genera and how this may affect species resolution via complete plastome barcodes. Pedicularis is a highly diversified group of plants whose floral traits have undergone rapid radiation in the Himalaya-Hengduan Mountains, which can complicate identification and classification within the group based on morphological traits alone. In this study, we analyzed 292 plastomes representing 96 species of Pedicularis to compare species discrimination rates with those based on standard DNA barcodes. The results show that the traditional standard barcode (nrITS+matK+rbcL+trnH-psbA) and the large single copy (LSC) region of the plastid genome share the highest discrimination rates (80.21%), followed by the plastid genome, the supermatrixes of protein-coding genes and high variable regions (79.17%), and the matK gene and ycf1 gene alone could discriminate 78.13% of species. Further, we found that the sequence length and percentage of parsimony-informative sites significantly influence species discrimination rates, and genes with higher species discrimination rates are more likely to be conservative in selection. Given the extra costs and time required for generating such “super-barcodes” to try to discern species in taxonomically complex genera, this study questions their use and calls for more efforts to explore nuclear markers that may improve discrimination rates in future studies with relatively low-cost and effort.

Polyploidy, or whole genome duplication (WGD) is widely regarded as key innovation promoting species diversification in plants. However, the hypothesis still remains controversial. Here, we tested the hypothesis by analyzing the association between polyploidy and the diversification of Araceae. Using 1081 single/low copy orthologous clusters from 90 transcriptome datasets, we generated a new time-calibrated phylogeny of Araceae. Based on Ks and gene tree methods, the special WGD event (abbreviation: ψ) was shared by the True Araceae clade, and not shared by Proto-Araceae and the lemnoids clade. By Analyses of time-dependent and trait-dependent diversification models, our results verified that the ψ WGD event was strongly associated with increases of net diversification rates of the True Araceae clade, but did not promote the diversification rates of Proto-Araceae and the lemnoids clade. Finally, functional enrichments analyses revealed that some genes in related to various binding, receptor and channel activity, DNA repair and cellular response to stress, such as heat shock protein, ABC transporter, Glycosyl hydrolase, RING finger, Pectin acetylesterase, Cytochrome P450 and Oxidative-stress-responsive kinase have experienced the expansions in the True Araceae clade. The expansions of these genes may contribute to the adaptation to the harsh tropical environment in the True Araceae clade. In summary, our results reconstructed the phylotranscriptomic framework of Araceae, revealed the diversification history of Araceae, and suggested that WGD may not act as the determining factor but the “Storage Cisterns” for species diversification.

Boehmeria nivea var. strigosa Zeng Y. Wu & Y. Zhao, a new variety of B. nivea (Urticaceae) from southwest China, is here described and illustrated based on evidence from morphology and molecular phylogeny. This new variety is mainly characterized by its green abaxial leaf blade, partly connate stipules, and densely patent strigose hairs. The phylogenetic relationship of rbcL showed that B. nivea var. strigosa formed a monophyletic group with a high support value. The conservation status of B. nivea var. strigosa is assessed as “Near Threatened” (NT) based on IUCN Criteria.

Mountainous regions can promote complex speciation scenarios, including hybridization leading to chloroplast capture, revealed by incongruent phylogenetic trees. Four allopatric Taxus lineages from the Hengduan Mountains, southwestern China, exhibit cytonuclear phylogenetic discordance. We use multi-omic data at the population level to investigate their historical speciation processes. Transcriptome data consistently showed that T. florinii and the Emei type, which are the focus of cytonuclear discordance, originated in the Late Miocene. Population genomic analysis based on ddRAD-seq data revealed limited contemporary inter-specific gene flow. However, neither taxon exhibited the mosaic nuclear genomes that usually characterized hybrids. Taxus florinii appears to have originated when a lineage of T. wallichiana captured the T. chinensis plastid type, whereas plastid introgression in the opposite direction generated the Emei Type. All four species have distinct ecological niches, and introgression might have contributed to, or even initiated, their ecological divergence. We propose that these speciation events represent very rare examples of chloroplast capture events despite the paternal cpDNA inheritance of Gymnosperms. These events might have been triggered by orogenic activities of the Hengduan Mountains and the intensification of the Asian monsoon in the late Miocene, and may represent a scenario more common in these mountains than presently known.