Evolution of Autonomous Selfing in Marginal Habitats: Spatiotemporal Variation in the Floral Traits of the Distylous Primula wannanensis

Outcrossing plant species are more likely to exhibit autonomous selfing in marginal habitats to ensure reproduction under conditions of limited pollinator and/or mate availability. Distyly is a classical paradigm that promotes outcrossing; however, little is known about the variation in floral traits associated with distylous syndrome in marginal populations. In this study, we compared the variation in floral traits including stigma and anther height, corolla tube length, herkogamy, and corolla diameter between the central and peripheral populations of the distylous Primula wannanensis, and assessed the variation of floral traits at early and late florescence stages for each population. To evaluate the potential consequences of the variation in floral traits on the mating system, we investigated seed set in each population under both open-pollinated and pollinator-excluded conditions. The flower size of both short- and long-styled morphs was significantly reduced in late-opening flowers compared with early opening flowers in both central and peripheral populations. Sex-organ reciprocity was perfect in early opening flowers; however, it was largely weakened in the late-opening flowers of peripheral populations compared with central populations. Of these flowers, disproportionate change in stigma height (elongated in S-morph and shortened in L-morph) was the main cause of reduced herkogamy, and seed set was fairly high under pollinator-excluded condition. Our results provide empirical support for the hypothesis on the evolution of delayed autonomous selfing in marginal populations of distylous species. Unsatisfactory pollinator service is likely to have promoted reproductive assurance of distylous plants with largely reduced herkogamy mimicking “homostyles.”

The comparative study of Alkanna and Huynhia (Boraginaceae, Lithospermeae), with description of a new species in Iran

A new blue to light violet-flowered species from SW Iran is described as Alkanna semiromica. The new species is morphologically close to A. frigida and Huynhia pulchra. Floral characters suggested the affinity of the new species to Huynhia, especially the stamens inserted at different heights in the corolla tube and also the plant trichomes while the pollen characters supported its place within the genus Alkanna. A comparison with the new species and the most similar genera is presented here based on new and old morphological data, to understand the differences among the species. In addition, the diagnostic characters, description, detailed illustrations, and taxonomic comments are presented.

Spiradiclis yuanyangensis (Rubiaceae), a new species from Yunnan, China

Spiradiclis yuanyangensis is described and illustrated from Yunnan Province in southwestern China. It is morphologically most similar to S. petrophila H. S. Lo, but differs from the latter mainly by its stem pubescent, corolla tube 4–5 mm (vs. ca. 2 mm) long, and short-styled corolla inside without a villous ring. A detailed description, line drawings and colour photographs are provided, together with notes on conservation status.

Synopsis of the Brazilian genus Symphyllophyton (Gentianaceae) with four new species

Symphyllophyton (Gentianaceae) is characterized by autotrophic herbs, with tetramerous flowers didynamous stamens, filaments attached to the distal portion of the corolla tube and connate-perfoliate or free leaves. The finding of a new population in the Brazilian State of Goiás inspired a detailed and unprecedented study of the genus, which lead to the discovery of four new species in different States and to the repositioning of Schultesia sucreana within the genus, thus elevating the known number of species from two to seven. A lectotype is designated for the genus. Descriptions, illustrations, and an identification key are provided along with notes on ecology and conservation.

Salvia fimbriaticalyx, a new species of Salvia (Lamiaceae) from Oaxaca, Mexico

In this study, we describe and illustrate Salvia fimbriaticalyx, a new species from Oaxaca, Mexico, which is morphologically similar to Salvia leptostachys, a species from section Angulatae. The new species differs from the latter by having persistent, lanceolate bracts with cuneate base; calyx lobes with a densely fimbriate margin; corolla tube longer (3–3.5 mm long), and the lower lip of the corolla shorter (3–3.5 mm long). Three molecular markers (ITS, trnL-trnF and trnH-psbA) were sequenced for the new species, and its phylogenetic position is discussed.

A New Distinctive Species of Schizanthus (Solanaceae) and the Reinstatement of Schizanthus fallax

Abstract— A new Schizanthus species from northern Chile is described and illustrated. Schizanthus nutantiflorus was discovered based on recent collections made during unusual rain events in the Atacama Desert in 2015. The new species is distinguished morphologically from other Schizanthus species from northern Chile by its short corolla tube, with a distinct upper lip arrangement and colour, having the longest lower lip, and downward-facing flowers. Additionally, the reinstatement of Schizanthus fallax is proposed. By using both nDNA and cpDNA, phylogenetic relationships among all species of Schizanthus were investigated. Molecular and field observations, as well as an exhaustive morphological revision of fresh material and herbarium specimens, supports the segregation of Schizanthus with short corolla tubes from northern Chile into three species. We propose that, in order to fully understand both the taxonomy and evolution of Schizanthus, an integrative framework encompassing molecular, ecological, and morphological data should be carried out. Information on distribution, habitat, informal conservation status, as well as taxonomic notes and illustrations are provided. In addition, an updated key for the species of Schizanthus from northern Chile is given.

Morphometrics and Redescription of Aphyllon fasciculatum and Aphyllon franciscanum, Two Widespread but Previously Conflated Species in Western North America

Abstract— We continue the taxonomic reevaluation of Aphyllon sect. Aphyllon by describing a widespread species throughout western North America previously recognized within a polyphyletic A. fasciculatum. To support our description and revised key, we analyzed fifteen continuous and discrete characters sampled from 186 herbarium specimens and iNaturalist observations representing the geographic and host ranges. Principal component and multiple correspondence analyses reveal clear variation in floral characters. Discriminant analyses show that three aspects of floral color, corolla lobe tip shape, the calyx cup to calyx lobe ratio, calyx lobe length, and degree of bend in the corolla tube are useful distinguishing features, but not diagnostic in every case.

Primulina cataractarum sp. nov. (Gesneriaceae) from limestone landform in Southern Hunan, China

A new species, Primulina cataractarum (Gesneriaceae) from limestone areas in southern Hunan, China, is described and illustrated with photographs based on morphological and molecular data. This new species is slightly similar to P. porphyrea and P. rubribracteata in morphology, but it can be easily distinguished by its smaller rounder leaves, large repand green bracts and purple corolla tube. Phylogenetic analysis proved that these three species are different, and their relationships are relatively distant. It also reveals that P. cataractarum is genetically similar to P. jiangyongensis, which is geographically next to the type locality of the new species, but they differ greatly in morphology. Following the IUCN Red List Criteria, P. cataractarum is assessed as Critically Endangered (CR B2a; C2b) because of its limited populations and vulnerable habitat.

Primula dujiangyanensis (Primulaceae) discovered from Sichuan, Southwest China

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.

Schwenckia aurantiaca (Solanaceae), a new species from calcareous outcrops of northern Minas Gerais, Brazil

A new species of Schwenckia (Solanaceae) from calcareous outcrops of the Serra Azul Biological Reserve in northern Minas Gerais, Brazil, is described and illustrated. Schwenckia aurantiaca is an annual plant characterized by a cylindrical corolla tube with five orange, linear appendages, an androecium with two stamens and three, unequal pilose staminodes, and a calyx that tears to the base in fruit. We discuss the morphological characters, habitat, and conservation status of the species, which is assessed as Critically Endangered.