Impatiensbeipanjiangensis (Balsaminaceae), a new species from Guizhou, China.

Impatiensbeipanjiangensis Jian Xu & H. F. Hu (Balsaminaceae), a new species of Impatienssubg.Clavicarpa discovered in Guizhou, China, is described and illustrated in this study along with its molecular phylogenetic analysis. I.beipanjiangensis is similar to I.liboensis, I.chishuiensis and I.clavigera in morphology, but I.tubulosa has the closest relationship to it. However, there are various ways in which the new species can be easily distinguished from these four species: Inferior nodes swollen rhizoid, pale green and with hooked outer sepals, longer lateral united petals, subovate auricle, deeper lower sepal and shorter spur that is reflexed towards the lower sepal. Furthermore, I.beipanjiangensis is distinguished from other Impatiens species, based on morphological, micromorphological and palynological evidence and molecular data (PP 0.967).

Oxalisxishuiensis (Oxalidaceae), a new species from Danxia landforms in Guizhou, China.

Oxalisxishuiensis, a new species of Oxalidaceae from Danxia landforms of Xishui County, Guizhou, China, is described and illustrated. It is morphologically similar to O.wulingensis by the two lateral leaflets arranged at about 180° angle and oblong pink petals with lilac veins, but clearly differs from the latter by leaflets almost as long as wide, obliquely obcordate lateral leaflets, shorter peduncles, longer capsule (1.2-1.5 cm vs. 0.5-0.7 cm) and alveolate seeds.

Hypericumliboense (Hypericaceae), a new species from Guizhou, China.

Hypericumliboense M.T.An & T.R.Wu, sp. nov. (Hypericaceae) is a newly described species found in the Maolan National Nature Reserve of Guizhou Province, where it grows in rocky habitats without soil on karst mountain tops. In this study, key morphological characters were compared between the new species and the other known Hypericum species of Hypericaceae. DNA sequences were extracted from the leaves of the new species, with nuclear gene sequences (ITS) generated to reconstruct phylogenetic trees and describe its phylogenetic position in relation to other species of Hypericum. Our results show that the proposed new species has the typical characteristics of the genus Hypericum in morphology being similar to Hypericummonogynum, but differing in its sessile and semi-clasped leaves, long elliptical to long circular leaf blades, thickly papery to thinly leathery, with entire and wavy leaf margins. The abaxial side of the leaves is covered with white powder, giving them a grey-white appearance. The main lateral veins of the leaves are 8-15-paired, and the midvein on both sides is convex. The main lateral veins and midvein branch are conspicuous, with tertiary venation forming a network on the leaf surface and appearing prominently sunken. The inflorescences are 1-3-flowered, with a large calyx and conspicuous veins. The molecular phylogenetic analysis (PP = 1.00) provided substantial evidence for the proposition of H.liboense as a new species within Hypericum. Morphological and molecular evidence is presented, corroborating the proposition of the new species, including a comprehensive account of the distinctive morphological attributes of H.liboense, along with its key distinguishing features from similar species.

Competition and synergistic mechanisms of species in Phyllostachys edulis-Alsophila spinulosa association based on niche theory.

We examined the niche characteristics and interspecific covariant relationship of main species in Phyllostachys edulis-Alsophila spinulosa association in Chishui A. spinulosa National Nature Reserve under P. edulis disturbance condition, and analyzed the mechanism of competition and coexistence across different species. The results showed that there were 67 species from 53 genera and 40 families in the association. The importance values, Shannon niche breadth index (BS), and Levins niche breadth index (BL) of P. edulis were the largest, indicating its absolute dominant status in association. The importance value and BL of A. spinulosa ranked the second, while BS was the third. There were 190 pairs of 20 main species. The niche overlap between P. edulis and A. spinulosa was the largest, with niche overlap value of 0.64. 71.6% of species pairs had niche overlap of less than 0.2, indicating low niche overlap and high degree of niche differentiation among species. The overall association of main species in association was significantly positive, and the community was relatively stable. The correlation among the main species was not significant, the linkage was not strong, and the species were independent from each other. P. edulis showed significant positive correlation with A. spinulosa, Brassaiopsis glomerulata, Ficus virens, and Mallotus barbatus, while P. edulis showed significant negative correlation with Mallotus philippensis, Cinnamomum glanduliferum, and Machilus gamblei. Niche difference and fitness between P. edulis and natives affected the coexistence and competition among species. Controlling the expansion of P. edulis and limiting the size of species with negative correlation with A. spinulosa could create a favorable living environment for A. spinulosa.

Impatiensyunlingensis (Balsaminaceae), a new species from Yunnan, China.

Impatiensyunlingensis S.X. Yu, Chang Y. Xia & J.H. Yu (Balsaminaceae), a species new to science discovered in Yunnan, China, is described and illustrated here, along with its phylogenetic position among other Impatiens species. Morphological, micro-morphological and molecular evidence is presented as an attestation of its novelty. Impatiensyunlingensis is similar to I.delavayi in having coarsely crenate leave margins, bracts in the upper part, ca. 4/5 length of the pedicels, saccate lower sepal with shallowly bifid spur, linear capsules, and elliptic-oblong, tuberculate seeds, but differs from I.delavayi with lateral sepals 4 (vs. 2), lateral united petal basal lobes subtriangular (vs. dolabriform), and seeds' surface equipped with tubercular ornamentation mostly covered with grain shaped appendages (vs. glabrous and without grain shaped appendages on the top).

Rediscovery of Pogostemon dielsianus (Lamiaceae, Lamioideae), a rare endemic species from southwestern China, after one century.

Pogostemon dielsianus (Lamiaceae) was described in 1913 based on a single gathering from northwestern Yunnan of China collected in 1905, and thereafter no further collections were observed until 2019. We rediscovered the rare endemic species in Lushui County, Yunnan. Molecular phylogenetic analyses based on four cpDNA markers (rbcL, rps16, psbA-trnH, and trnL-trnF) and the nuclear ribosomal internal transcribed spacer (ITS) region confirmed its infrageneric placement within subg. Pogostemon. Based on observations of the rediscovered population of P. dielsianus, we updated its morphological description, provided an illustration, and discussed its distribution. Under IUCN criteria, the species was categorized as "Critically Endangered (CR)".

The Complete Chloroplast Genome of the Vulnerable Oreocharis esquirolii (Gesneriaceae): Structural Features, Comparative and Phylogenetic Analysis.

Oreocharis esquirolii, a member of Gesneriaceae, is known as Thamnocharis esquirolii, which has been regarded a synonym of the former. The species is endemic to Guizhou, southwestern China, and is evaluated as vulnerable (VU) under the International Union for Conservation of Nature (IUCN) criteria. Until now, the sequence and genome information of O. esquirolii remains unknown. In this study, we assembled and characterized the complete chloroplast (cp) genome of O. esquirolii using Illumina sequencing data for the first time. The total length of the cp genome was 154,069 bp with a typical quadripartite structure consisting of a pair of inverted repeats (IRs) of 25,392 bp separated by a large single copy region (LSC) of 85,156 bp and a small single copy region (SSC) of18,129 bp. The genome comprised 114 unique genes with 80 protein-coding genes, 30 tRNA genes, and four rRNA genes. Thirty-one repeat sequences and 74 simple sequence repeats (SSRs) were identified. Genome alignment across five plastid genomes of Gesneriaceae indicated a high sequence similarity. Four highly variable sites (rps16-trnQ, trnS-trnG, ndhF-rpl32, and ycf 1) were identified. Phylogenetic analysis indicated that O. esquirolii grouped together with O. mileensis, supporting resurrection of the name Oreocharis esquirolii from Thamnocharisesquirolii. The complete cp genome sequence will contribute to further studies in molecular identification, genetic diversity, and phylogeny.

The complete chloroplast genome of the threatened Dipentodon sinicus (Dipentodontaceae).

Dipentodon is a monotypic genus of Dipentodontaceae and the only species, Dipentodon sinicus, is scattered in southwest China as well as adjacent Myanmar, northeast India and northern Vietnam. This species was evaluated as vulnerable in 'China Species Red List'. Here, we assembled and characterized the complete chloroplast (cp) genome of D. sinicus using Illumina sequencing data for the first time. The complete cp genome was 158,795 bp in length, consisting of a pair of inverted repeats of 26,587 bp, a large single-copy region of 87,233 bp and a small single-copy region of 18,388 bp. The genome encoded 113 unique genes, including 79 protein-coding genes, 30 tRNA genes and four rRNA genes. Phylogenetic analysis based on 16 complete cp genome sequences indicated that D. sinicus is a member of Huerteales, consistent with its position in the latest classification of flowering plants (AGP IV).