Several previous studies have shown that some morphologically distinctive, small genera of vascular plants that are endemic to the Qinghai-Tibetan Plateau and adjacent Hengduan Mountains appear to have unexpected and complex phylogenetic relationships with their putative sisters, which are typically more widespread and more species rich. In particular, the endemic genera may form one or more poorly resolved paraphyletic clades within the sister group despite distinctive morphology. Plausible explanations for this evolutionary and biogeographic pattern include extreme habitat specialization and hybridization. One genus consistent with this pattern is Nomocharis Franchet. Nomocharis comprises 7–15 species bearing showy-flowers that are endemic to the H-D Mountains. Nomocharis has long been treated as sister to Lilium L., which is comprised of more than 120 species distributed throughout the temperate Northern Hemisphere. Although Nomocharis appears morphologically distinctive, recent molecular studies have shown that it is nested within Lilium, from which is exhibits very little sequence divergence. In this study, we have used a dated molecular phylogenetic framework to gain insight into the timing of morphological and ecological divergence in Lilium-Nomocharis and to preliminarily explore possible hybridization events. We accomplished our objectives using dated phylogenies reconstructed from nuclear internal transcribed spacers (ITS) and six chloroplast markers.

Primula dujiangyanensis, a new species from Dujiangyan, Sichuan of China, is described and illustrated here. The new species is morphologically similar to P. kialensis and P. pengzhouensis, but it can be distinguished from the latter species by dense white hairs at roots, long stolons, smaller plants and leaves, solitary scape arising from leaf rosette, single lanceolate bract, and shorter pedicel, and it also showed different positions of anthers and styles in the corolla tube.

Rubus L. (Rosaceae, Rosoideae) contains around 700 species distributed on all continents except Antarctica, with the highest species diversity in temperate to subtropical regions of the northern hemisphere. The taxonomy of Rubus is challenging due to the frequency of polyploidy, hybridization and apomixis. Previous studies mostly sampled sparsely and used limited DNA sequence data. The evolutionary relationships between infrageneric taxa, therefore, remain to be further clarified. In the present study, genotyping by sequencing (GBS) reduced-representation genome sequencing data from 186 accessions representing 65 species, 1 subspecies and 17 varieties of Rubus, with emphasis on diploid species, were used to infer a phylogeny using maximum likelihood and maximum parsimony methods. The major results were as follows: (1) we confirmed or reconfirmed the polyphyly or paraphyly of some traditionally circumscribed subgenera, sections and subsections; (2) 19 well-supported clades, which differed from one another on molecular, morphological and geographical grounds, were identified for the species sampled; (3) characteristics such as plants with dense bristles or not, leaves leathery or papyraceous, number of carpels, instead of inflorescences paniculate or not, aggregate fruits and leaves abaxially tomentose or not, may be of some use in classifying taxa whose drupelets are united into a thimble-shaped aggregate fruit that falls in its entirety from the dry receptacle; and (4) a preliminary classification scheme of diploid species of Rubus is proposed based on our results combined with those from previous phylogenetic analyses.

Discerning species boundaries among closely related taxa is fundamental to studying evolution and biodiversity. However, species boundaries can be difficult to access in plants because ongoing divergence and speciation may leave an evolutionary footprint similar to introgression, which occurs frequently among species and genera. In this study, we sought to determine species boundaries between two closely related alpine shrubs, Rosa sericea and Rosa omeiensis, using population genetics, environmental data and ecological niche modeling, and morphological traits. We analyzed populations of R. sericea and R. omeiensis using genetic markers comprising a fragment of the single-copy nuclear gene, LEAFY, micro-satellites (EST-SSR), and plastid DNA sequences. The DNA sequence data suggested clusters of populations consistent with geography but not with previously proposed species boundaries based on morphology. Nevertheless, we found that the ecological niches of the previously proposed species only partially overlap. Thus, we suspect that these species are in the process of parapatric speciation; that is, differentiating along an ecological gradient, so that they exhibit differing morphology. Morphology has previously been the basis of recognizing the species R. sericea and R. omeiensis, which are the most widely distributed species within a broader R. sericea complex that includes several other narrow endemics. Here, we recognize R. sericea and R. omeiensis as independent species based on morphological and ecological data under the unified species concept, which emphasizes that these data types are of equal value to DNA for determining species boundaries and refining taxonomic treatments. While the DNA data did not delimit species within the R. sericea complex, we expect to develop and utilize new, robust DNA tools for understanding speciation within this group in future studies.

In this research, the pollen morphology of the Rosa sericea complex has been studied by Scanning Electron Microscope (SEM). The present study aimed to provide baseline information for the taxonomic identification of the R. sericea complex taxa. The pollen sculpture, outline, and aperture show variability in the studied taxa. The R. sericea complex includes taxonomically challenging species with undistinguishable boundaries. Identifying taxon boundaries in closely related species is fundamental to investigating evolution and biodiversity. Taxa circumscription of R. sericea complex is insufficient, unresolved, and is a prerequisite for comprehensive systematic revisions. To resolve these issues, we have attempted to identify some important diagnostic characters for the species of R. sericea complex. This research studied different qualitative and quantitative characteristics of R. sericea complex pollen. The qualitative characteristics included polar and equatorial view, sculpture, pollen outline, apertures, exine, size category, and polarity of pollen. In contrast, the quantitative features include polar and equatorial diameter, P/E, colpi length and width, and distance between colpi. Pollen of this complex is mono and tricolporate. The morphological characters studied here provide very few taxonomic details with which to separate the species of the complex into distinct taxa. Some of the studied characters offer important information for species delimitation including sculpture, pollen outline, and apertures.

We studied hybrid interactions ofLilium meleagrinum,Lilium gongshanense, andLilium saluenenseusing an integrative approach combining population genetics, fieldwork, and phenological research. These three species occur along an elevational gradient, withL. meleagrinumoccurring at lower elevations,L. saluenenseat higher elevations, andL. gongshanensebetween them. The species show strong morphological differentiation despite there being no clear environmental barriers to gene flow among them.Lilium gongshanenseis likely to have a hybrid origin based on our prior work, but its progenitors remain uncertain. We sought to determine whether gene flow occurs among these three parapatric species, and, if so, whetherL. gongshanenseis a hybrid ofL. meleagrinumand/orL. saluenense. We analyzed data from multiple chloroplast genes and spacers, nuclear internal transcribed spacer (ITS), and 18 nuclear Expressed Sequence Tag-Simple Sequence Repeat (EST-SSR) microsatellites for accessions of the three species representing dense population-level sampling. We also inferred phenology by examining species in the field and using herbarium specimens. We found that there are only two types of chloroplast genomes shared among the three species and thatL. gongshanenseforms two distinct groups with closest links to other species ofLiliumbased on ITS. Taken together,L. gongshanenseis unlikely to be a hybrid species resulting from a cross betweenL. meleagrinumandL. saluenense, but gene flow is occurring among the three species. The gene flow is likely to be rare according to evidence from all molecular datasets, and this is corroborated by detection of only one putative hybrid individual in the field and asynchronous phenology. We suspect that the rarity of hybridization events among the species facilitates their continued genetic separation.