Ophiopogon Ker‐Gawl. (Ophiopogoneae, Asparagaceae) is a genus containing approximately 65 species distributed in East and Southeast Asia. The biogeographical history within the area is still poorly known. Divergence time estimation was used to infer the biogeographic history of Ophiopogon based on nuclear ribosomal internal transcribed spacer data from 33 Ophiopogon species, three Liriope Lour. species, and six Peliosanthes Andrews species. The ancestral area and dispersal routes of Ophiopogon were inferred using the Bayesian binary method. Ophiopogon motouensis S. C. Chen was a transitional taxon. Ophiopogon was estimated to have originated in Southwest China during the middle Miocene (11.74 Ma). Five migrations were hypothesized to explain the expansion of Ophiopogon from Southwest China to East China, South Central China, South China, Taiwan, and Southeast Asia. The separation of Ophiopogon into East China and South Central China may be consistent with a broad east–west arid zone in continental Asia during the Paleogene. A migration from Southwest China to Taiwan was inferred in the Pliocene, when the ancestor of O. intermedius D. Don may have moved from Southwest China through the Yunnan–Guizhou Plateau by the Nanling Corridor and Fujian–Taiwan Bridge into Taiwan. There was a dispersal route in the Pliocene (at 3.79 Ma) from Southwest China to South China, either along the Taiwan route (from Southwest China through the Yunnan–Guizhou Plateau along the Nanling Corridor to Guangxi), or related to the E'mei Mountain orogeny. There was another dispersal event in the early Pleistocene at 2.00 Ma from Southwest China to Southeast Asia, possibly associated with the last uplift of the Qinghai–Tibetan Plateau.

Brassicaceae, one of the most diverse and economically valuable plant families, is distributed all over the world. Previous studies have suggested that Brassicaceae originated and diversified in the Old World. In this study, the phylogenetic relationships of 17 tribes of Brassicaceae from the Qinghai–Tibet Plateau (QTP) and adjacent areas were investigated using nuclear ribosomal internal transcribed spacer (nrITS) and chloroplast DNA sequence data (rbcL and petB‐petD) with maximum likelihood, maximum parsimony, and Bayesian methods. As suggested by both the nrITS and chloroplast DNA trees, Cardaria pubescens (C.A.Mey.) Jarm. (Lepidieae) and Draba lanceolata Royle (Arabideae) should be classified in the Eutremeae and Cardamineae, respectively. Based on over 700 newly sequenced and published nrITS sequences of Brassicaceae, an up‐to‐date comprehensive phylogeny of the family was reconstructed using the maximum likelihood method. In the phylogenetic tree, 10 monophyletic tribes were detected. They were used to clarify the lineage diversification and dispersal patterns of the 10 tribes. The results showed that most of the monophyletic tribes may have originated in different regions of the world, and then dispersed into other regions surrounding the QTP. Rapid lineage diversification rate shifts were detected in several tribes, such as Anastaticeae, which experienced a rapid shift event ∼1.38 Mya, corresponding to the rapid uplift of the QTP, indicating that the recent uplift of the QTP could have promoted diversification in Brassicaceae across and adjacent to the QTP.

Species boundaries have traditionally been delimited by applying phenotypic characters to a morphological species concept. With an increased understanding of the complexities of speciation as a process, species concepts have proliferated while at the same time, the ability to gather greater numbers and types of molecular characters has expanded the means by which species can be delimited. Phylogenetic studies of molecular data provide an opportunity to identify reciprocally monophyletic groupsand have led to the identification of cryptic or nearly cryptic species in which subtle differences in phenotypes or ecological niches can be uncovered only after monophyletic groups have been identified. Here, we investigate evolutionary relationships among a group of species in the Lomatium triternatum complex using molecular phylogenetic analyses for all samples, and ecological parameters for two of the 38 species included in this study. The results indicate that there are more reciprocally monophyletic groups in this complex than had been estimated using phenotypic data alone. The ecological data show a clear differentiation for the one pair of sister species where ecological sampling was available, implying that divergence within this group may have resulted from environmental selection for soil preferences that have been strong enough to result in speciation.

The study of variation in nuclear genome size, especially when combined with common garden experiments, significantly contributes to disentangling interspecies relationships within taxonomically complicated plant groups. The Chenopodium album aggregate is among the morphologically most variable groups and consists of many weakly differentiated cosmopolitan entities. We analysed nuclear genome size variation in diploid and polyploid species of the aggregate from Iran using flow cytometry of 282 accessions from 88 populations of 7 species. To this end, we also determined chromosome numbers and performed a morphometric study to reveal the extent of intraspecific morphological variation. We found that Iranian species are exclusively diploid (C. vulvaria), tetraploid (C. novopokrovskyanum, C. strictum, C. sosnowskyi and C. chaldoranicum) or hexaploid (C. album subsp. album, C. album subsp. iranicum and C. opulifolium). Six homogeneous relative genome size groups were distinguished among the species studied. Our morphometric study surprisingly revealed that under similar ecological conditions Chenopodium species are morphologically stable and well distinguishable, exhibited very little morphological variation. Hence, immense variation in leaf shapes, branching and inflorescence organization seen in the field has not been repeated under greenhouse conditions. The only exception was C. album s. str. which exhibited numerous morphotypes, covering the variation of remaining species.

Loss of local, effective pollinators may potentially limit plant reproductive success but the plant–pollinator interactions could be rescued if the plant does not reject other pollen vectors. Firmiana kwangsiensis H.H. Hsue (Malvaceae) is an endangered tree endemic to limestone areas in South China. Although its preservation status is listed as “critically endangered”, its reproductive ecology is little known. We compared floral visitors in three wild populations and one transplanted population. Such a comparison allows us to see whether the pollinator assemblage varies geographically and to examine the plasticity of plant–pollinator interactions, informing sustainable ex situ conservation. Our pollination experiments indicated that fruit/seed set in F. kwangsiensis largely depended on pollinator visits, and was greatly reduced under hand self‐pollination or exclusion of bird visits. Floral visitors included sunbirds, butterflies, and bees (honeybee and wasp) but their visitation frequency varied in the four populations. The sunbird Nectarinia jugularis was the major pollinator in the three wild populations, but was replaced by the other sunbird Aethopyga christinae in the ex situ population. This tree is showy, with orange‐red flowers blooming before the leaves emerge. The calyx tube accumulates a large volume of dilute nectar (sugar concentration was 9.5%) in the morning, rewarding sunbird pollinators. Our investigations indicated that sunbirds rather than insects served as a functional group of pollinators for this endangered species. Successful ex situ conservation of this type of plant needs to consider the availability of potential pollinators.

The ribosomal DNA (rDNA) repeats of more and more species have been found to be polymorphic in the genome, and the understanding of this polymorphism is conducive not only to eliminating potential chaos in the metagenomic analysis (MGA), but also to providing rich information on rDNA evolution. In this study, the MGA previously used for the study of environmental microbial diversity was improved and extended to detect the intragenomic polymorphism (IGP) of rDNA in three species of Camellia L. The 3′‐end region of 26S rDNA of three individuals was amplified using degenerate primer pairs. Three annealing temperatures were applied to obtain as many ribotypes as possible, and equimolar amplicons from the three species were then pooled and sequenced using the Illumina MiSeq platform. An incredibly high level of IGP of rDNA was found in all three species. Nearly all of the ribotypes detected from this study were rDNA pseudogenes, and most of them have existed for a long time in the genome, with some generated from several rapid expansions. Our procedure provided an effective technique for detection of IGP of rDNA, and the particular evolutionary information of rDNAs in Camellia was also exploited.