Invasive alien plants in China: An update.

•The latest 403 invasive alien plants in China are updated.•A summary of five volumes of 'Alien Invasive Flora of China' and recent invasive plants reports.•Compared with weeds, invasive plants emphasis on the destruction of biodiversity and native ecosystems.•Classical plant taxonomy is the basis of invasive plants research.

Flora of Mongolia: annotated checklist of native vascular plants.

In this study, we critically revised and updated the checklist of native vascular plants of Mongolia. The checklist comprises 3,041 native vascular plant taxa (2,835 species and 206 infraspecific species) from 653 genera and 111 families, including 7 lycophytes, 41 ferns, 21 gymnosperms, and 2,972 angiosperms. In the angiosperms, we identified the 14 families with the greatest species richness, ranging from 50 to 456 taxa. Species endemism is also noted here; 102 taxa are endemic to Mongolia, and 275 taxa are sub-endemic that co-occur in adjacent countries. Since 2014, a total of 14 taxa have been described new to science based on morphological evidences. Moreover, five genera and 74 taxa were newly added to the flora of Mongolia. Based on our critical revisions, names of three families, 21 genera, and 230 species have been changed in comparison to the previous checklist, "Conspectus of the vascular plants of Mongolia" (2014).

Taxonomic studies on the genus Isotrema (Aristolochiaceae) from China: II. I. brevilimbum (Aristolochiaceae), a new species from Guizhou, China.

A new species of Isotrema was recently discovered from Guizhou, China and is here named as I. brevilimbum. It is most similar to I. ovatifolium and I. wardianum, but differs in the morphology of leaves and flowers. A detailed description for the new species, along with line drawings, photographs, as well as morphological comparisons with similar species, are provided. In addition, the distribution of I. wardianum in China is here confirmed.

Extraction, characterization and antioxidant activity of polysaccharide from Pouteria campechiana seed.

In this study, the seed polysaccharides (PCSP) was ultrasonic-assisted extracted from Pouteria campechiana and optimized by response surface method (RSM). After separation and purification by DEAE-52 cellulose column and Sephadex G-75 glucan gel column, the pure polysaccharide component of PCSPa-1 was obtained, and its structure and antioxidant activity were analyzed. The results showed that the optimal parameters of PCSP with maximum yields (15.94%) were ultrasonic temperature of 79 °C, ultrasonic time of 69 min, and liquid to material ratio of 41 mL/g. The molecular weight of PCSPa-1 was 67900 Da. PCSPa-1 consisted of glucose and mannose with a molar ratio of 86.65:4.62, and the glycosidic bond mainly included →4)-α-d-Glc(1→ and →6)-α-d-Glc(1→. Scanning electron microscopy showed that PCSPa-1 was a strip structure with a smooth surface. In addition, PCSPa-1 had strong scavenging capacity to 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis- (3-ethylbenzthiaz oline-6-sulphonic acid) (ABTS), hydroxyl radical, and superoxide radical. Polysaccharides of Pouteria campechiana seeds could be exploited as a natural antioxidant.

Taxonomic studies on the genus Isotrema (Aristolochiaceae) from China: I. I. cangshanense, a new species from Yunnan.

Isotrema cangshanense X.X.Zhu, H.L.Zheng & J.S.Ma, a new species from western Yunnan, China, is described and illustrated here. It is similar to I. utriforme, I. forrestianum, I. cucurbitoides and I. obliquum The major differences between them are outlined and discussed. A detailed description, along with line drawings, photographs, habitat and distribution, as well as a comparison to morphologically similar species, is also provided. Meanwhile, the new taxon is assessed as Vulnerable (VU D2), according to the IUCN Red List criteria.