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A new lithophytic species, Paraboea zunyiensis T.Deng, F.Wen & R.B.Zhang (Gesneriaceae), inhabiting Karst rocks in northern Guizhou, China, is introduced and depicted in this study. It bears a resemblance to P. crassifolia (Hemsl.) B.L. Burtt, yet is distinguishable by its shorter filaments and staminodes, triangular ovate calyx segments, and ovaries surpassing the styles in length. Moreover, the phylogenetic tree constructed from nuclear DNA (ITS) and plastid DNA (trnL-F) data firmly support the differentiation of this novel species from P. crassifolia.

Petrocodon wui F.Wen & R.B.Zhang (Gesneriaceae), a typically lithophyte occurring in the Danxia areas of north-western Guizhou, China, is described and illustrated as new to science. The new species shows overall similarity with P. chishuiensis Z.B.Xin, F.Wen & S.B.Zhou, which is also its sister species, based on molecular evidence. The new species can be distinguished from P. chishuiensis by the elongated rhizome, the relatively long indumentum on the peduncle, the shape, size and indumentum of calyx lobes, the location of the stamens in the corolla tube and the shape, size and indumentum of the stigma. We provide a diagnosis, detailed description, photographic images and a table with taxonomic notes to distinguish several other morphologically similar Petrocodon species.

Rebar corrosion is the principal factor affecting the service performance of reinforced concrete (RC) structures. Corrosion reduces the effective area of rebars as well as performance, and weakens the pin bolt effect of rebar on concrete. In addition, when the rebar is severely rusted, the concrete cover breaks, and the bond behavior between reinforcement and concrete deteriorates, affecting the mechanical properties of RC structures. In this study, a three-dimensional numerical model for shear analysis incorporating the nonuniform corrosion of reinforcement was established using an RC beam as the research object. The effects of corrosion on the mechanical behavior of the RC beam were explored via a multistage analysis method (namely, corrosion-induced expansion stage and structural deterioration stage). To model and simulate the expansion of the corrosion products, nonuniform radial displacement was applied to the concrete surrounding the rebar. The cracking process and the damage patterns of concrete resulting from corrosion were obtained. Then, taking the corrosion state as the initial condition, the static load was applied to analyze the mechanical behavior of the RC beam. After verifying the rationality of the multistage numerical model, the effect of the corrosion of tensile reinforcement and the shear-span ratio on the shear behavior of concrete beams without web reinforcement was analyzed. The modeling analysis results show that the corrosion of longitudinal reinforcement causes obvious longitudinal corrosion fractures in the concrete beam. Moreover, with the development of corrosion, the cracking area of the protective layer increases, reducing the shear capacity of the beam significantly. Furthermore, the shear-span ratio has a larger effect on the shear capacity of noncorroded beams than that of corroded beams. Finally, based on the simulation results, the calculation formulas of shear capacity in relevant design codes were discussed, and a methodology for predicting the shear capacity of RC beams without web reinforcement was proposed.

Primulina serrulata is a valuable ornamental herb with rosette leaves and vibrant flowers. Some leaves of this species exhibit a bright and distinct white color along the upper veins, enhancing their ornamental value, while others are less white or entirely green. This variation is observed in adult leaves from natural habitats and among young leaves from seedlings grown in the laboratory. TMT-labeled proteomics technology was used to study the protein-level biogenesis of white-veined (WV) P. serrulata leaves. Our objective was to offer novel insight into the breeding of WV plants. Chlorophyll (Chl) content was significantly lower in the WV group than in the control group. Out of 6261 proteins identified, a mere 69 met the criteria for differentially expressed proteins (DEPs) after stringent screening for subsequent analyses. Among these DEPs, there were 44 proteins that exhibited downregulation and 25 that were upregulated in the WV plants. Some DEPs associated with chloroplasts and Chl biosynthesis were downregulated, leading to the absence of green coloration. Concurrently, Gene Ontology enrichment analysis further emphasized an insufficiency of magnesium, the key element in Chl biosynthesis. Many DEPs associated with abiotic or biotic stressors were downregulated, suggesting an overall weakening of stress resistance with certain compensatory mechanisms. Similarly, many DEPs related to modifying biomacromolecules were downregulated, possibly affected by the decrease in proteins involved in photosynthesis and stress resistance. Some DEPs containing iron were upregulated, indicating that iron is mainly used to synthesize heme and ferritin rather than Chl. Additionally, several DEPs related to sulfur or sulfate were upregulated, suggesting strengthened respiration. Expansin-A4 and pectinesterase were upregulated, coinciding with the emergence of a rough and bright surface in the white area of leaves, indicative of the elongation and gelation processes in the cell walls. These findings provide new insight for future studies to explore the mechanism of color formation in WV leaves.

Paraphlomis kuankuoshuiensis (Lamiaceae), a new species found in the limestone areas of northern Guizhou, China, is described and illustrated in this paper. Based on its tubular-campanulate calyx, this taxon should be a member of sect. Paraphlomis Prain. The new species resembles P. patentisetulosa C.Y. Wu & H. W. Li, P. hispida C.Y. Wu, and P. hirsutissima C.Y. Wu & H.W. Li, but differs from these three taxa in the following aspects: the stems are very short (

We describe and illustrate Sedum lipingense (Crassulaceae), a new species of stonecrop found in the limestone areas of SE Guizhou, China. Based on the presence of adaxially gibbous carpels and follicles, this taxon belongs to sect. Sedum S.H. Fu. The new species superficially resembles S. subtile Miquel and S. bulbiferum Makino but differs from these two taxa in its development of a basal leaf rosette during florescence. The nrDNA internal transcribed spacer (ITS) sequences also support the claim that this plant is a new species in the Sedum genus.

Primulina serrulata R.B.Zhang & F. Wen, a new species from a limestone area in southeastern Guizhou, China, is described and illustrated here. The new species is morphologically related to P. fimbrisepala (Hand.-Mazz.) Y.Z.Wang. We examined the morphological differences between these congeners and provide illustrations and photographs of this new species in this paper.

The newly discovered Paraphlomis youyangensis, native to southeastern Chongqing, China, is introduced to the scientific community. This species exhibits similarities in floral structure to P. kuankuoshuiensis but is distinguishable by several discrete features, such as less pronounced rhizomes (<0.5 vs. 2-4 cm), elongated stolons (present vs. absent), smaller leaf blades (1.8-5.5 x 1.2-3.1 vs. 10-37 x 3-8 cm), leaf margins (shallowly repand and mucronulate vs. serrulate), and shorter bracteoles (1.2-4 vs. ca. 5 mm). Phylogenetic assessments based on two nuclear genes and three chloroplast genes indicated that P. youyangensis has a closer evolutionary relationship with P. yingdeensis but is differentiated from the latter by long stolons, smaller leaf blades (vs. 6.2-16.5 x 4-11.5 cm), leaf margins (vs. crenate-serrate), and notably shorter bracteoles (vs. 7-8 mm). [ABSTRACT FROM AUTHOR]