To explore the potential suitable distribution and ecological adaptability of Rhodiola tangutica on the Qinghai-Xizang Plateau， based on 38 distribution sites of Rhodiola tangutica across the plateau and seven environmental factors across current and future five periods， a relationship model between the distribution of Rhodiola tangutica and environmental factors was constructed using the MaxEnt model. The potential geographical distribution patterns for the current period（1970-2000） and four future periods（2030s， 2050s， 2070s and 2090s） under the SSP245 scenario were simulated and verified. The findings revealed that： （1）Altitude（Alt） and precipitation of the driest month（Bio14） were the most important ecological factors influencing the geographical distribution of Rhodiola tangutica， contributing rates of 89.3% and 4.9%， respectively. （2）under the current climatic context， the total suitable distribution area of Rhodiola tangutica on the Qinghai-Xizang Plateau was approximately 195.21×10? km2， predominantly situated in the southern and northeastern parts of Qinghai， northwestern Sichuan， and central Xizang. （3）compared with the current period， the total suitable distribution area of Rhodiola tangutica in the next four periods would not change obviously； however， the area of high suitability would increase， with a tendency of concentrated distribution to the central Qinghai-Xizang Plateau.
To understand the distribution characteristics of Amygdalus mongolica， a rare and endangered Tertiary in the Mongolian Plateau， and its response to future climatic change， climate and soil variables with 121 population distribution points of A. mongolica were selected， and the comprehensive habitat suitability model（CHS） in the R software Biomod2 modeling platform was constructed， which was used to simulate and predict suitable habitat under the current climatic condition and three different future climate scenarios（SSP1-2.6、SSP3-7.0 and SSP5-8.5） in the future（2050S and 2090S）， and the spatial and temporal evolution characteristics was analyzed， and the migration pattern of suitable habitat was explored. The results showed that the TSS of the climate suitability model （ensemble model） was >0.75， the ROC of the distribution limitation model was >0.90， which indicated that the comprehensive habitat suitability model selected in this study might accurately simulate the potential geographical distribution characteristics of A. mongolica under different climate scenarios. The suitable habitat area of A. mongolica at present was 64.00×104 km2， mainly distributed in Inner Mongolia， Gansu and Ningxia， a small number distribution in Qinghai， Xinjiang， Shaanxi， Shanxi， Hebei and other places. The suitable habitat area of A. mongolica showed a decreasing trend under three climate change scenarios（SSP1-2.6， SSP3-7.0， SSP5-8.5） in the future， and the suitable habitat area under different climate scenarios in 2090S was smaller than that in 2050S. Its suitable distribution area extended to the west and higher latitudes as a whole.
The Northeastern region of China is one of the important distribution areas of wild Ribes， and many records of the genus in this region are incomplete or even incorrect. There is an urgent need to summarize the species and distribution of the wild Ribes in this region. Field investigation on the wild Ribes in northeast China was conducted， and the Flora of China， the northeast plants search contents， and the Northeast vascular plants survey were consulted， and related papers and electronic documents and websites were reviewed respectively. The results showed that there were six subgenus and 22 species（including eight varieties） of the wild Ribes in northeast China. Heilongjiang Province had the largest number of wild Ribes， with 12 species and two varieties， Jilin Province had eight species and four varieties， Liaoning Province had five species and four varieties， and the eastern part of Inner Mongolia Autonomous Region had seven species and two varieties. The wild Ribes in the northeast China mainly distributed in the Greater Khingan Mountains， the Lesser Khingan Mountains， the Changbai Mountains， and the coast and islands of the Liaodong Peninsula； the number of species and subgenus of this genus in the northeast China was consistent in horizontal distribution. The wild Ribes in the Lesser Khingan Mountains had the largest number of species and subgenera， and was the modern distribution center of the wild Ribes in northeast China. The Ribes in the northern part of the northeast was dominated by hermaphroditic groups， while in the southern part of the Northeast Most of them were unisexual groups. This genus was distributed from low altitude（≤200 m） to high altitude（1 800-2 100 m）， and most species were concentrated at an altitude of 300-800 m. The endemic phenomenon of this genus was very obvious. There were as many as 15 species（including six variants） endemic to domestic regions， accounting for 68%. The wild Ribes in northeast China had many species， rich resources， wide distribution and huge development potential. However， its living environment was under threat. We should pay close attention to the dynamic changes of its population and distribution area in order to take measures to protect it in time.
To explore the composition and phylogenetic diversity of species， endemics， and threatened species in different geographic units of Yunnan， and to provide scientific basis for biodiversity conservation and sustainable resource utilization in Yunnan. Based on the comprehensive Yunnan monocotyledon species database， the spatial distribution pattern of monocotyledon plants in Yunnan was revealed by using species richness， weighted endemic， threatened index， phylogenetic diversity， phylogenetic endemic， and evolutionary distinctiveness and globally endangered index， respectively， and the distribution of nature reserves was integrated， and the key areas for biodiversity conservation in Yunnan was identified. The results showed that species richness of Yunnan monocotyledons was significantly（P<0.001） and positively correlated with phylogenetic diversity， weighted endemism with phylogenetic endemism， threatened index with evolutionary distinctiveness and globally endangered； northwestern， southern， and southeastern Yunnan possessed the highest diversity and endemism in terms of species composition and phylogenetic composition； and the standardized phylogenetic diversity was higher in all regions except for northwestern and southeastern Yunnan； Northwestern， southern and southeastern Yunnan were the key conservation areas for monocotyledonous plants， and effective measures to protect them would help maintain the evolutionary history and evolutionary potential of biodiversity in the region.
Protected plants usually have high utilization value or a small population size， and are the plant groups facing the highest survival threat， and are also one of the focus objects of biodiversity conservation. Based on the systematic survey of key protected wild plants in Wenshan Prefecture， the abundance and geographic distribution of them were analyzed， and the weights were determined by using four indicators， including endangerment coefficient， genetic value coefficient， protection coefficient， and utilization value coefficient， and then the integrated value of priority protection for these plants were calculated， and the different levels of priority protection to species were classified. The results showed that the387 species of wild plants were identified under priority protection in Wenshan Prefecture， including 36 species under national-level priority protection， 259 species at the second level， 24 species under priority protection at the second level in Yunnan Province， and 78 species at the third level， respectively. Orchidaceae family accounted for 38%（112 species） of the wild plants under national-level priority protection， was an important protected taxon in Wenshan Prefecture. From the horizontal distribution level， Malipo， Maguan and Xichou Counties in the south had high species richness with 228， 224， and 200 species， respectively. On the other hand， Guangnan， Qubei and Yanshan Counties in the north-central part had lower species richness with 87， 68 and 52 species， respectively. In terms of vertical distribution， the elevation range of 1 301 to 1 500 m was the most concentrated area for wild key protected plants. Therefore， biodiversity protection efforts should focus on the southern region and areas with an altitude of 1 301 to 1 500 m. The combined value of priority protection ranged from 0.372 to 0.940， resulting in 39 species classified as Class Ⅰ， 142 species as Class Ⅱ， 123 species as Class Ⅲ， and 83 species as Class Ⅳ. Eight species， including Begonia gulinqingensis， Camellia fascicularis， Horsfieldia tetratepala， Cymbidium qiubeiense， Camellia crassicolumna var. multiplex， Dysosma pleiantha and Cypripedium henryi， were not listed as threatened species in the “China Biodiversity Red List-Higher Plants Volume（2020）”， but were assessed as Class Ⅰ Priority Conservation due to their small number of distribution individuals， and significant human disturbance and high conservation value. These species should be considered urgent targets for rescue and protection.
In order to explore the potential suitable distribution area and the suitable living environment of Corydalis trachycarpa， and to provide a theoretical basis for resource utilization and protection of C. trachycarpa. Based on the existing distribution sites， climatic variables， and environmental variables of C. trachycarpa， MaxEnt modeling and ArcGIS software were used to simulate the potential distribution of C. trachycarpa in China for four periods under current climate condition（1970-2000） and Shared Socioeconomic Pathway（SSP） 245 scenario model（2021-2040， 2041-2060， 2061-2080， 2081-2100）， and environmental factors limiting its distribution were analyzed. The results showed that the most important environmental factors determining C. trachycarpa distribution were altitude（Alt， contribution rate was 60.9%）， standard deviation of temperature seasonality（bio4， contribution rate was 11.1%）， precipitation during the warmest quarter（bio18， contribution rate was 9.4%）， and the precipitation variation coefficient（bio15， contribution rate was 7.0%）. The cumulative contribution of these four factors was 88.4%. Under current climate conditions， the MaxEnt model predicted a total potential distribution area of approximately 1.7494×106 km2 for C. trachycarpa， primarily distributed in northwest Sichuan， southern Gansu， eastern Xizang， northwest Yunnan， and Qinghai within the eastern Tibetan Plateau. Compared with the current climate conditions the most， moderate and low suitable areas of C. trachycarpa under SSP 245 scenario might increase in the next four periods， showing a trend of expansion toward Yunnan， eastern Xizang， and other lower latitude regions.
The systematic position of Messerschmidia L. has been problematic which was ever moved into Tournefortia L. or Heliotropium L. Sporogenesis and gametogenesis in Messerschmidia sibirica were observed using conventional paraffin sectioning and light microscopy to provide embryological data for a better understanding of the systematic position of Messerschmidia. The results were as follows： （1）The anther was tetra-sporangiate， the primarily matured anther wall comprised four layers： the epidermis， endothecium， a middle layer and tapetum， the development of the anther wall was of the Dicotyledonous type， the tapetum with two-nucleate cells was secretary， the epidermis was persistent and the endothecium was irregularly 2- layered with fibrous thickening； （2）Microsporocyte undergone a meiotic division with a simultaneous cytokinesis resulting in a tetrahedral microspore tetrad， the mature pollen grains were 2-celled； （3）The ovule was unitegmic， anatropous and crassinucellate with a long thin micropyle and weak integument tapetum， some of the nucellar tissue was persistent at the stage of mature embryo sac； （4）The development of the embryo sac was of a Polygonum type， the shape of the mature embryo sac was fusiform with polar nuclei fused before fertilization and antipodal cells already degenerated. The embryological characters of Messerschmidia sibirica might be very similar to those of Heliotropium. Considering the stability of embryological characters within genus， the results suggested that it might be suitable to classify Messerschmidia into Heliotropium based on the molecular phylogenies.
Dipteris shenzhenensis is a critically endangered（CR） plant distributed only in Shenzhen. The phyto-community analysis of this dominant community was studied and analyzed， and the results showed that： there were 85 species， 73 genera and 49 families of vascular plants in Dipteris shenzhenensis community， the dominant species included Gordonia axillaris， Ilex memecylifolia， Cyclobalanopsis neglecta， Enkianthus quinqueflorus， Litsea rotundifolia var. oblongifolia， Dipteris shenzhenensis， Dicranopteris pedata； Plant individuals in this community decreased with the increase of tree height， showing an “Inverted J” type distribution， which was an obvious characteristic in subtropical areas. The diversity and evenness index of all life forms showed a trend of “high in the middle and low in the two ends”； The T test of the species diversity index of different communities in the same area proved that there was no significant difference in diversity level between different communities， which belonged to the stable stage of ecological succession； Niche analysis revealed the survival status of Dipteris shenzhenensis in the community， indicating that this species was not widespread， demanding for environment and poor competitiveness in resources， and there was a risk of extinction during community succession； Interspecific association analysis revealed the interspecific relationship between this species and other dominant herbs， and identified possible complementary and competitive plants.
To explore the effects of multi-walled carbon nanotubes in gametophyte development and sporophyte production of Ceratopteris thalictroides， and to lay a foundation for conservation and breeding of endangered ferns.C. thalictroides was used as material， and five treatment group of 0（the control）， 0.5， 1.0， 2.5， 5.0 mg·L-1 was set，and the effects of different mass concentrations of multi-walled carbon nanotubes on gametophyte development and sporophyte formation of C. thalictroides were observed by light microscope. The results showed that compared with the control group， 0.5-2.5 mg·L-1 multi-walled carbon nanotube treatment could advance spore germination by about 15 d， among them， 0.5 mg·L-1 multi-walled carbon nanotubes had the best effect on spore germination， 0.5-1.5 mg·L-1 multi-walled carbon nanotubes had the best effect on protonema and plate formation， and 2.5 mg·L-1 multi-walled carbon nanotubes had the best effect on prothallus and sporophyte formation. High mass concentration （5.0 mg·L-1） of multi-walled carbon nanotubes led to deformity of some gametophytes， and spermogonium degradation， chlorosis of chloroplasts in cells， and chlorosis of chloroplasts in some cells on the developing sporophytes cells. In addition， male gametophytes was promoted by the addition of multi-walled carbon nanotube. In conclusion，0.5-2.5 mg·L-1 multi-walled carbon nanotube treatment might significantly promote gametophyte development and sporophyte production of C. thalictroides， and the number of spermogonium increased significantly， and both monoecious and dioecious gametophytes appeared simultaneously， high mass concentration of multi-walled carbon nanotube treatment might result in‘high concentration inhibition’ of gametophyte development of C. thalictroides. In the process of practical application， the corresponding addition amount should be selected based on the specific need.
Since its establishment in 2002， no taxonomic study on the genus Eurhynchiastrum Ignatov & Huttunen has been carried out in China. Based on the related specimens and literatures， the authors conducted an investigation on the genus in China. The results showed that the genus was distributed in China with a single species， E.pulchellum（Hedw.） Ignatov & Huttunen. The morphological characters， habitats and geographical distribution of the species were described. Additionally， a plate illustrating the main morphological features was provided， and a discussion on the comparison among allied genera and species was included. Furthermore， the potential geographic distribution of E.pulchellum in China was predicted.
Based on the survey of orchid resources in the lower Yarlung Zangbo River region， the priority protection value of each endangered plant was quantitatively calculated using multiple evaluation indexes to determine the endangerment level and priority protection sequence of rare and endangered orchids in the region by combining data collection and specimen review. The endangerment level of 156 species of endangered orchids in 60 genera in the lower Yarlung Zangbo River region was evaluated， among which 15 species were in critically endangered（CR） status， 46 species in endangered（EN） status， 78 species in vulnerable（VU） status and 17 species in near threatened（NT） status； the priority protection range value was 0.853 9-0.416 8， among which 45 species were classified as Class Ⅰ protected plants， 72 species as Class Ⅱ protected plants， and 39 species as Class Ⅲ protected plants.The results of this study differ greatly from the endangered degree and priority protection level of various protected plant lists， and most of the orchids are under enhanced threat in this region， which is consistent with the real survival status of these orchids in the lower Yarlung Zangbo River area， and the protection of orchids in this region is urgent and should be given sufficient attention.
In order to explore the karyotype characteristics and evolutionary relationship of different populations of Sophora alopecuroides， the karyotype characteristics and evolutionary of six natural geographic populations distributed in Inner Mongolia， Gansu， Ningxia were analyzed respectively， and chromosome conventional slicing technology was used. The results showed that the number of chromosomes in six populations of S. alopecuroides was constant，2n=2x=36. There were two types of central centromere（m） chromosome and sub-central centromere（sm） chromosome in three populations. Chromosomes of most populations were only central centromere chromosome except for Population 3 in Wuwei， Gansu， with central centromere and sub-central centromere chromosome. The average arm ratio of chromosomes ranged from 1.19 to 1.37， the length ratio was between 1.72 and 2.19， and the karyotype asymmetry coefficient was from 54.30% to 57.17%. There were three types of karyotypes including 1A， 3A and 2B for S. alopecuroides. The karyotype asymmetry coefficient of population 3 of S. alopecuroides was the largest and the evolutionary degree was the highest， while those of population 19（Ordos， Inner Mongolia） was the smallest and the lowest. Cluster analysis showed that the six populations of S. alopecuroides were aggregated into two major branches of A and B. Branch A could be divided into two subclades of C and D. Among them， population 5（Wuwei， Gansu） and population 13（Alxa， Inner Mongolia） were clustered into subclade C， which had the closest relationship， whereas population 3 was clustered into subclade D alone， which was relatively distant with two populations from subclade C. Similarly， branch B could be further divided into subclade E and subclade F respectively. Subclade E was consisted of population 19 and population 43（Ordos， Inner Mongolia）， which had the closer relationship， while Subclade F only contained population 17（Yinchuan， Ningxia）， which had the relatively distant with two populations from subclade E. In this study， the chromosome number， karyotype characteristics and evolutionary trend of S. alopecuroides were discussed at the population level， which provided cytological evidence for further studying the system and evolution， and genetic diversity of germplasm resources of S. alopecuroides.
The perennial fern Pteris vittata（Pteridaceae） is a hyperaccumulator of arsenic and is used for remediation of soils contaminated by heavy metals. In order to identify the characters that the P.vittata sporophyte thrives in xeromorphic rocky environments and hyperaccumulates ions， the brightfield and epifluorescence microscopy were used to investigate the anatomical structures and histochemical features of this species. The results were as follows： （1）The structure of the rhizome， adventitious roots and leaves of P. vittata sporophytes were all primary structures， the adventitious roots had an vascular bundles， endodermis with Casparian band， lignified sclerenchyma layers， cortex， rhizodermis. （2）The rhizomes had a dictyostele， endodermis， cortex， epidermis， cuticle. （3）The stipes had a single vascular bundle with a central endodermis， cortex， sclerenchyma layers， while the epidermis had a cuticle. The pinnae had bifacial mesophyll with palisade tissue and spongy tissue， the epidermis had a cuticle. （4）The surfaces of the rhizodermis and the root hairs were pectin-rich and underlain by a lignified cortex， and permeability tests using a berberine tracer showed that these structures retained large volumes of berberine. In summary， the suberized endodermis， lignified sclerenchyma layers， bifacial mesophyll， and a cuticle， all of which reflect an adaption to xeromorphic rocky environments. The result of the berberine permeability test are consistent with the hyperaccumulation of ions by P. vittata.
In order to rationally protect and explore the wild poisonous plant resources in the Namjagbarwa region， the distribution of families and genera， the composition of life forms， the toxicity， poisonous parts and toxicological effects of plants were analyzed by field investigation， specimen investigation and related literature books inspection. The results showed that there were 77 families， 167 genera and 242 species of wild poisonous plants in the Namjagbarwa region， among which the dominant families mainly included Araceae， Ranunculaceae， Ericaceae， Fabaceae and Asteraceae respectively. The most poisonous plants with herbaceous life form were 138 species in total. Most of the plant toxic parts were poisonous whole grass， a total of 109 species. There were 184 species with mild poisonous plants， including 50 minor toxic plants， there were only five kinds of highly poisonous and three kinds of strong poisonous. There were 19 poisonous nectar source plants， Scrophulariaceae and Ranunculaceae were dominant； in terms of toxicology， most of them were nervous system poisoning. There were many kinds of poisonous plant resources in the Namjagbarwa region， but there was less use of these resources. It was necessary to strengthen the understanding and protection of poisonous plants， and carry out rational development and explroation.
To improve the characteristics of the spore，elater and oil body of Lophoziaceae and to provide detailed information for classification，the morphology of 11 species of the Lophoziaceae was observed by scanning electron microscopy， 6 species provided for the morphological characteristics of spore and elater，and 9 species provided for oil body. The results showed that：①The spores of 6 species of Lophoziaceae were spherical， near spherical or elliptical with brown， reddish-brown or yellowish brown respectively. The spore size of them were from 10-16 μm belonging to MI type，and their faces near pole were usually concave. The ornamentation of the above spores were verrucose，clavate，spinate，granular or short baculite respectively. ②The elaters of 6 species of Lopholoziaceae were densely bispiral with obtuse both ends，and their cuticle were smooth or granulate.③The oil bodies of 9 species of Lophoziaceae were spherical，elliptical or oval，with the diameter between 3-10 μm. The detailed description and illustration on morphological evidence of spores，elaters and oil bodies of 11 species of Lophoziaceae might provide the elemental data for the systematic taxonomy and evolution of Lophoziaceae.
To identify the cell types and analyze the transport mechanism of vascular tissue and explore the cell evolution during tree evolution，a comprehensive anatomical study was carried out on a kind of special tracheids of Tetracentron sinense. After slicing and dissociating， the distribution position and morphological characteristics of the special tracheids of the 34-year-old T. sinense were observed by using optical microscope and scanning electron microscope. The results showed that the special tracheids were arranged from the inside to the outside radially in the horizontal of the tree， and ran through the growth ring boundary. Most of them were in one row， and few were in two rows. And each special tracheid was connected with wood ray cells on one or both sides. In the longitudinal direction， the special tracheids were connected individually or with several cells terminally. There were three main types of special tracheids： fusiform without end wall， fusiform with one sloping end wall or with two sloping end walls. The average length of special tracheids was 286.44 μm. Its cross section was quadrilateral. The average tangential width of special tracheids were 55.22 μm respectively. The average wall thickness of special tracheids was 1.53 μm. The two ends of the special tracheids were closed without perforation. The number of pits on the side wall of special tracheids was large and the pit membrane was clearly visible. There were a large number of bordered pits on the wall in tangential section， which were arranged in opposite， alternated and scalariform pitting. The single pits on the radial wall were rounded or ellipse. There were 2-10 pits， arranged in 1-4 rows in per region. There were no pits between the special tracheids and the normal tracheids on the radial wall. The distribution of special tracheids has certain regularity. Compared with normal tracheids， the special tracheids were much shorter in length， and the tangential width were slightly larger. The type and arrangement of the pits were similar to those of the pits on the wall of general hardwood species. The shape of the special tracheid was different from the general vessel in the hardwood， and it was in an intermediate state of the evolution from tracheid to vessel， indicated a certain level of evolution of this type of cell.
Akebia trifoliata belongs to Akebia of the Lardizabalaceae family， and it is a dioecious， monoecious woody vine， with economic value for medicine and food. In order to understand the sexual reproduction process of A. trifoliate， analyze the reproductive reasons of the low seed setting rate of this species under natural conditions， and provide a theoretical basis for its hybrid breeding and new variety cultivation，the embryological characteristics of mega-and microsporogenesis and female and male gametophyte development of A. trifoliate were observed by paraffin section technology. The main results showed that A. trifoliata had six stamens with four locules in each， and the anther wall was fully differentiated， and it was composed of epidermis（1 layer）， endothecium（1 layer）， middle layers（2-3 layer） and tapetum（1 layer） from outside to inside， tapetum belonged to glandular type respectively. The cytokinesis of the microspore mother cell in meiosis was of simultaneous type， and the tetrads were arranged in a tetredraltah， mature pollen grain was two-celled. There were little pollen abortion， and abortion occurred at the microspore tetrad stage. The ovary was one locular， parietal placentation， ovules were hemianatropous， bitegminous and crassinucellate. Its megaspore was of monosporogenesis type， and tetrads were linearly arranged. The chalazal end megaspore developed into functional megaspores， which underwent three times consecutive mitosis and further developed into polygonum embryo sac with seven cells and eight nucleus，another three megaspores degenerated. The early development of the stamens in the female flowers was normal， but the microspores did not develop further until the uninucleate pollen grain stage， the tapetum was not completely degraded， and the anther wall did not crack， the degeneration of the carpel of the male flowers was due to the early lack of development，the carpels heal incompletely， and no ovules are produced.The process of the mega-microsporogenesis and development of female and male gametophyte of A. trifoliata were normal， which was not the reason for the low seed setting rate， but may be related to external factors affecting pollination.
To investigate the genetic and phylogeography structure of Artemisia intramongolica， which was an important sand-fixing plant in Hunsandak sandy land in China， the homologous single-copy nuclear genes c9065 and c7847 were developed by transcriptome sequencing， and then eight natural populations of A. intramongolica were studied. The results showed that the total length of c9065 and c7847 were 485 bp and 457 bp， respectively， with 14 and 19 variable loci， and 48 and 40 haplotypes were obtained. Based on c9065 and c7847， the haplotype diversity（Hd） was 0.871 6 and 0.934 8， respectively， and all populations were above 0.8. The total nucleotide diversity（π） was 0.008 2 and 0.005 9， respectively， and all populations were above 0.005， indicating that both species and populations had high genetic diversity. The results of AMOVA analysis showed that 99.398% and 98.908% of genetic variation existed within the populations of A. intramongolica based on c9065 and c7847， respectively， with gene flow（Nm）of 6.810 and 7.270， respectively， much greater than 1， indicating that there was extensive gene exchange among populations of A. intramongolica. Based on c9065， Nst<Gst， although Nst>Gst by c7847， but the difference was not significant（P>0.05）， indicating that A.intramongolica population did not exist phylogeographic structure. The neutral test showed that Tajima’s D values for both nuclear genes were all not significant（P>0.05）， while Fu’s Fs values were all significant（P<0.05）， and combined with the mismatch distribution analysis， A.intramongolica experienced limited population expansion under the neutral mode.
To clarify the codon usage pattern and phylogenetic relationship of the chloroplast genome between Ranunculaceae and Paeoniaceae， 33 species of Ranunculaceae and seven species of Paeoniaceae were used as materials， and the analysis software CodonW， online software CUSP， and R software were used to analyze the codon characteristics of chloroplast genes， while the MAFFT software， MEGA software were used for phylogenetic analysis respectively. The results showed that the chloroplast genomes of Paeoniaceae and Ranunculaceae （except Columbine） had a high consistency of high frequency codons， with 29 high frequency codons， which were basically biased towards ending with A/U， but the optimal codon were different. The codon bias of the chloroplast genome of Ranunculaceae and Paeoniaceae was mainly influenced by natural selection， and the codon bias of the chloroplast genome of Paeoniaceae was more affected by natural selection than that of Ranunculaceae. The phylogenetic relationship based on the complete chloroplast genome sequence and the CDS sequence of the chloroplast genome showed that although the phylogenetic relationship based on the complete chloroplast genome sequence and the chloroplast genome CDS sequence of Paeoniaceae was different， they could be divided into the peony group and the peony group. The phylogenetic relationship of Ranunculaceae based on the entire chloroplast genome sequence did not conform to the classification relationship of Chinese flora， but it supported the division of Ranunculaceae into four subfamilies and 14 families. The analysis results supported that Paeoniaceae were independent from Ranunculaceae and Ranunculus， and were classified into Saxifraga.
Brachytheciaceae is one of the most diverse and problematic taxonomic families in pleurocarpous mosses. In this paper， the morphology of pseudoparaphyllia of 594 specimens in Brachytheciaceae， which belonged to 19 genera and 44 species， were studied. Results were as follows： ①In Brachytheciaceae， pseudoparaphyllia was triangular to semicircular foliose. According to its apical characteristics， pseudoparaphyllia could be divided into two types： truncate or obtuse， and acuminate. ②Except for the genus Brachythecium， morphology of pseudoparaphyllia among the different species in the other 18 genera was basically the same. ③Morphology of pseudoparaphyllia had taxonomic significance in the genus level.
