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1.
Deyeuxia sorengii B. Paszko & W. L. Chen, a new species of Deyeuxia from the Qinghai‐Tibetan Plateau, China, is described and illustrated. The new species is morphologically similar to D. zangxiensis P. C. Kuo & S. L. Lu, but differs from it by having a well‐developed and conspicuously hairy rachilla prolongation and a straight awn. Deyeuxia sorengii occurs in alpine meadows of central Xizang and central Qinghai. The first records of Deyeuxia zangxiensis are reported from western and eastern Xinjiang and northeastern Qinghai (China).  相似文献   

2.
The micro‐morphology of nutlets in 30 taxa (28 species and 2 varieties) of Microula Benth. (Boraginaceae) was surveyed by light and scanning electron microscopy. A principal coordinate‐based ordination analysis (PCO) (8 morphological and 14 micro‐morphological characters) was applied to explore whether taxa clustered according to the current sectional taxonomy. The nutlet epidermis showed three major features: trichomes, papillae and lamellae. Two basic trichome types could be identified: branched and unbranched. Stellate trichomes (STT) and stipitate stellate trichomes (SST) can be considered as two subtypes of branched trichomes based on shape and branching location. Three kinds of unbranched trichomes were recognized by their shapes: slender trichomes (SLT), spear‐like trichomes (SPT) and conical trichomes (CT). Four types of papillae were revealed in this genus: central apiculate papillae (CAP), debris‐covered convex papillae (DCP), rugous papillae (RP) and tabular papillae (TP). The lamellae was classified in five types: glossy lamellae (GL), thread‐like lamellae (TL), rugous lamellae (RL), interrupted lamellae (IL) and debris‐covered lamellae (DCL). The variation in the nature of surface sculpturing, nutlet shape and size, dorsal aperture shape, and attachment scar positions proved useful diagnostic characters. Taxa belonging to the same section generally clustered together in the PCO analysis. A key based on the morphology and micro‐morphology of nutlets is provided to distinguish the sections of Microula. The presence of SLT, STT, DCP and DCL is consistent with the macro‐morphological classification and provides additional evidence for the subgeneric delimitations. The SST, SLT, CAP, DCP, RP, DCL, GL and RL are useful in discriminating species in Microula. Additionally, the distribution of some trichomes, papillae and lamellae types is correlated with the altitudinal distribution of the species.  相似文献   

3.
Morphological characteristics, as well as ultrastructure of pollen grains, chromosome numbers and karyotype analysis have been used to establish a new species of Saussurea from the Qinghai–Tibetan plateau. The new species, Saussurea pseudograminea Y. F. Wang, G. Z. Du et Y. S. Lian is easily distinguished from the similar S. graminea Dunn by having 2–3 capitula, involucre 0.7–1.2 cm in diameter, smaller pollen grains, pollen surface with larger and denser spines, achenes 4.0–5.5 mm long, 32 chromosomes, and a karyotype formula 2n = 2x = 32 = 18m + 10sm + 4st, whereas S. graminea has solitary capitula, involucre 1.2–2.0 cm in diameter, larger pollen grains, pollen surface with smaller and sparser spines, achenes 3–4 mm long, 28 chromosomes and a karyotype formula 2n = 2x = 28 = 6m + 20sm + 2st. The new species is distributed in Dianzhangou, Awanchang, and Gamaliang mountain regions of Maqu county in Gansu province.  相似文献   

4.
Onosma maculata Ranjbar & Almasi, a new Boraginaceae species endemic to Iran, is described and illustrated. The new species belongs to Onosma sect. Onosma subsect. Onosma. It is closely related to O. nervosa Riedl, but is easily distinguished by its spotted stem and peduncle (vs no spots), leaves 14–23 cm long (vs leaves 4–12 cm long), pedicel 5–15 mm long (vs pedicel 3–5 mm long), higher density of hairs, and glabrous nutlet (vs villous). Moreover, meiotic chromosome number and behavior were studied in two populations of the new species and it was found to be diploid with 2n = 2x = 16.  相似文献   

5.
Based on field investigations as well as morphological and molecular systematic studies we found a new species of Bothriospermum which can be easily distinguished from all other known congeneric species by its unlobed faucal appendages and very long styles. We conducted molecular phylogenetic analyses based on a combined dataset from nrITS, plastid rps16, trnL‐trnF and trnG‐trnS regions. The results indicated that the new species indeed belongs in Bothriospermum and that it is well separated from other congeneric clusters, but that the genus Bothriospermum is paraphyletic with Nihon and Thyrocarpus clusetered within it. As a result, Bothriospermum longistylum sp. nov. is described and illustrated here. A revised key to species of Bothriospermum and a distributional map are also presented.  相似文献   

6.
Trigonotis jiaochengensis Q. R. Liu & R. Y. Yan, a new species from Shanxi, China, is described and illustrated here. It is similar to T. peduncularis in having multiple diffuse stems, ovate to elliptic leaf blades, scorpioid cyme with only basal bracts and trigonous‐tetrahedral nutlets, but differs in having slender pedicels that are 5.2–18.4 mm long (vs clavate pedicels 1.5–4.8 mm in T. peduncularis), smooth nutlets with a short carpophore and a flat bottom (vs verrucose nutlets with a long carpophore and convex bottom in T. peduncularis). Morphological characters, including pollen and nutlets, with illustrations, diagnostic comparisons and habitat, are presented.  相似文献   

7.
The new species Nonea dumanii, endemic to the mountains of the western Taurus in south Turkey (C4 Antalya), is described an illustrated based on original collections by the authors. Karyological observations and analysis of ITS1 DNA sequences showed that the species is probably hexaploid with 2n = 6x = 60 and has phylogenetic affinity to the diploid N. monticola from the Paphlagonian mountains as well as to the tetraploid N. anchusoides from northwest Iran and southeast Turkey. From these allopatric species it is morphologically distinct in characters of the indumentum, flower and fruit. Polyploidy is supported as a major driving force for speciation in Nonea, especially in the group of Anatolian mountain species with primary base number x = 10.  相似文献   

8.
Freshwater fish belonging to the genus Schizopygopsis are widespread in drainages throughout the Qinghai‐Tibetan Plateau and, thus, a model group with which to investigate how paleo‐drainage changes linked to historical uplifting within the Qinghai‐Tibetan Plateau influence speciation. To date, the phylogenetic and taxonomic relationships within Schizopygopsis remain controversial. In this study, we constructed a comprehensive molecular phylogeny of Schizopygopsis based on six mitochondrial gene sequences. We compared the taxonomic relationships revealed by this phylogeny with those obtained from morphological data. We also used this phylogeny to assess the extent to which the evolution of Schizopygopsis has been driven by paleo‐drainage changes linked to uplifting of the Qinghai‐Tibetan Plateau. Results indicated that all Schizopygopsis taxa formed a monophyletic group comprising five major clades, which were inconsistent with the taxonomic relationships based on morphology for this group. Our results also strongly supported the validity of S. anteroventris and S. microcephalus as distinct species within Schizopygopsis. Molecular calibrations showed that species within the middle Yangtze species diverged earlier (~4.5 Mya) than species within the Indus River (~3.0 Mya), the Mekong River (~2.8 Mya) and the Tsangpo + Salween rivers (~2.5 Mya). The most recent evolutionary splits occurred among species from the upper and lower Yangtze River, the Yellow River and the Qiadam Basin at about 1.8 to 0.3 Mya. Our molecular evidence and use of the molecular clock calibration have allowed us to associate speciation events within the genus Schizopygopsis to the formation and separation of paleo‐drainage connections caused by tectonic events during the uplifting of the Qinghai‐Tibetan Plateau (~4.5 Mya). This work underlines the dominant role of vicariance in shaping the evolutionary history of the genus Schizopygopsis. Further research using multiple loci and more extensive sampling will reveal a more complete picture of the phylogenetic relationships and biogeography of Schizopygopsis fishes.  相似文献   

9.
Myosotis wumengensis, a distinct new species endemic to Yunnan Province, China, is described and illustrated. The new species differs from all Myosotis species in China by having exserted anthers and a long corolla tube. Phylogenetic analysis confirms the generic position of the new species. In addition, the pollen morphology of the new species is described.  相似文献   

10.
1. Having analyzed the external morphology of the genus Microula, the author has proposed a series of criteria as bases for the construction of a classification scheme of this genus. The most important ones are as follows: 1) The normally developed stem is primitive, and the strongly abbreviated stem more advanced. 2) The small inconspicuous bracts are more primitive than the large suborbicular densely arranged ones, which almost entirely cover the flowers and the fruits. 3) Nutlets with small dorsal pit are more primitive than those with larger pit on one hand or those without it on the other. 4) The dorsal pit with simple margin precedes that with double margins. 5) Nutlets with subbasal areola precede those with lateral or apical areola. 6) Nutlets without glochids precede those with glochids. 2. Basing upon these criteria the genus Microula may be divided into six sections. The section Schistocaryum may be the primitive one, and the others may be evolved from it respectively. The possible affinities between them are demonstrated in figure no. two. 3. The genus Microula, containing 30 species, is mainly distributed in the Chinghai-Tibetan plateau and the majority of its species concentrates in the eastern border of the plateau, and of the 30 species 26—that is 90 percent—are endemic to China, and the remaining 4 are distributed elsewhere in China, too, and extending southward and westward to Bhutan, Sikkim, Nepal and Kashmir respectively. In the region between Heishui, Province Szechuan, and Chinghai Lake there are 9 species, which, curiously, represent all the six sections of Microula, hence this region seems to be the center of maximum variation of this genus. M. ovalifolia whose nutlets have small dorsal pit and subbasal areola may be considered the most primitive species. Thus the author is of the opinion that the western part of province Szechuan, to which M. ovalifolia is endemic, may probably be the center of origin of the genusMicroula.  相似文献   

11.
We used the Allium przewalskianum diploid–tetraploid complex on the Qinghai‐Tibetan Plateau (QTP) as a model to examine how this complex responded to the Quaternary climatic oscillations, and whether multiple autopolyploidizations have occurred. We sequenced five chloroplast DNA (cpDNA) fragments (accD‐psaI, trnH‐psbA, trnL‐trnF, trnS‐trnG and rpl16‐intron) in 306 individuals (all of known ploidy level) from 48 populations across the distribution of this species complex. We identified a total of 32 haplotypes—11 in diploids only, 13 in tetraploids only, and 8 found in both cytotypes. This, plus network analyses, indicated that tetraploids have arisen independently from diploids at least eight times. Most populations in the eastern QTP contained multiple haplotypes, but only a single haplotype was found for 17 tetraploid populations on the western QTP, suggesting a recent colonization of the western QTP. We further found that this species complex underwent an earlier range expansion around 5–150 thousand years ago (kya), after the largest glacial period (800–170 kya) in the QTP. In addition, the high frequencies of tetraploids in the QTP suggested that the tetraploid A. przewalskianum cytotype has evolutionary advantages over diploids in colonizing and/or surviving the arid habitats of the QTP.  相似文献   

12.
The new species Mollugo brasiliensis Thulin & Harley, a perennial viscous herb with 6–8 stamens, few‐seeded capsules and tuberculate seeds, is described from eastern Brazil. It is compared primarily with the two other native members of Molluginaceae previously known from Brazil, M. verticillata L. and Glischrothamnus ulei Pilger.  相似文献   

13.
Cremanthodium latilobum Y. S. Chen and C. medogense Y. S. Chen, two new species from Chinese eastern Himalaya are described and illustrated. A diagnostic key to the species of Cremanthodium section Pinnatinervia Y. Ling & S. W. Liu series Cuneata Y. Ling & S. W. Liu is provided.  相似文献   

14.
Data from eight microsatellite loci were used to infer the evolutionary and past demographic processes in 97 Tibetan snowcocks sampled from eight different geographical locations on the Qinghai–Tibetan Plateau. Analysis of the microsatellite DNA markers indicated that Tibetan snowcock on the plateau were geographically structured, and that phylogenetic analyses identified three phylogroups, namely those from Xunhua, the Qilian Mountains and all others. The use of Bayesian Clustering and Population Assignment analyses of the microsatellite genotypes revealed clear differentiation among the eight sampled groups of Tibetan snowcock, indicating strong isolation of these sub-populations. Therefore, we suggested that the distribution pattern of Tibetan snowcock observed today resulted from adaptation to the climatic conditions and glacial cycles on the Qinghai–Tibetan Plateau. In addition, BOTTLENECK analysis indicated that Tibetan snowcock had recently passed through evolutionary bottlenecks. These results suggested that effective conservation measures should be undertaken to protect Tibetan snowcock from an increased probability of extinction.  相似文献   

15.
Pollen grains of 16 species of Microula Benth. and six species of three related genera were examined under LM and SEM, and four of them also under TEM. Pollen grains of Microula and three related genera are dumb-bell-shaped, 3-colporate apertures alternate with three pseudocolpi. Pollen grains are very small,ranging from 12.18 x 7.13 μm to 6.36 x 3.66μm. In general, colpi with os are wider and shorter, rhomboid, but sometimes they are equal to pseudocolpi in length. Colpus margins are regularly or irregularly tooth-like. The surface of colpi is psilate or processed. Ora are circular or lalongated in outline, protruded or not; surface of os membrane is smooth or scabrid. The exine is usually indistinctly layered under LM. The exine surface is psilate, and more or less perforate. TEM examination shows that the pollen wall is differentiated into exine and intine: the exine includes ectexine and endexine, while the ectexine consists of tectum, columellae and foot-layer. However, there are differences in constriction of equatorial area, apertural characters, ornamentation and exinous ultrastructure between these genera. Pollen morphology indicates that the genus Microula Benth. is primitive, directly related to the genus Actinocarya Benth .; the genus Asperugo L. Is more advanced. The genus Eritrichium Schrad. which has two ora or one os and is anisopolar, represents the most advanced group among them. Noteworthily, the diorate phenomenon is found for the first time not onlyin the genus but in the family Boraginaceae.  相似文献   

16.
Cynoglossopsis somaliensis H. Riedl, sp. nov., is described as a new species of the hitherto monotypic genusCynoglossopsis Brand which is closest related toCynoglossum L. but has to be included inBoraginoideae-Eritrichieae from the way the nutlets are attached to the gynobasis.
  相似文献   

17.
The terrestrial diatom Microcostatus schoemanii sp. nov. is described from dry soils of the Faan Meintjies Nature Reserve (North‐West Province, South Africa). Microcostatus cholnokyi sp. nov. and Microcostatus angloensis sp. nov. are described from sandy soils at a colliery near the town of Kriel (Mpumalanga Province, South Africa). The morphology of these taxa is examined using both light and scanning electron microscopy and new taxa are compared with similar species. In M. schoemanii the density of the striae combined with the valve outline and the distance between the central raphe endings are the main distinguishing morphological features. M. cholnokyi is differentiated by the presence of a conopeum and the distinct structure of the microcostae. M. angloensis is similar to M. schoemanii but differentiated by the shape of the cell and the apices, the angle of striation and the distance in between the proximal raphe endings.  相似文献   

18.
Photinia taishunensis G. H. Xia, L. H. Lou & S. H. Jin (Rosaceae, Spiraeoideae) from Zhejiang, China, is described and illustrated. It has previously been confused with P. lochengensis Yü, but differs in details of habit, leaf size, leaf shape, inflorescence, flower size and pubescence. The pollen grains of P. taishunensis are monads, elliptical with trisulcate apertures, and the exine is rugulose, dotted with sparse punctures.  相似文献   

19.
Carex zhejiangensis X. F. Jin, Y. J. Zhao, C. Z. Zheng & H. W. Zhang, a new species of Carex sect. Rhomboidales sensu Kükenthal (Cyperaceae) from Zhejiang, eastern China, is described with illustrations. This new species is morphologically similar to C. filipes and C. macroglossa. Compared to C. filipes, C. zhejiangensis has elongated rhizomes, scattered culms, rather densely flowered pistillate spikes, achenes shortly stipitate at the base, and styles erect at the base. In contrast, C. filipes has short rhizomes, caespitose culms, sparsely flowered pistillate spikes, achenes obscurely stipitate at the base, and styles curved at the base. C. zhejiangensis differs from C. macroglossa by having elongated rhizomes and scattered culms, pistillate scales awned at apex, and perigynia contracted to a narrowly infundibuliform beak at apex. Diagnostic morphological characters, which are based upon population sampling, were analyzed in Carex zhejiangensis sp. nov., C. filipes and C. macroglossa.  相似文献   

20.
Plateau uprisings and climatic oscillations are considered to have caused extensive allopatric divergences that account for the rich species diversity of the Qinghai‐Tibetan Plateau (QTP). However, secondary contact during range shifts in the Quaternary glacial cycles or inter‐uplift stages may have restored the gene flow between species and so counteracted these divergences, particularly in rapidly‐adapting dominant elements. We tested this hypothesis by determining the phylogeographical history of Dasiphora (Rosaceae), a genus of two species that are widely distributed on the QTP and co‐exist in numerous localities. We sequenced two chloroplast DNA fragments (rbcL, trnT‐L) for 559 individuals from 87 populations. Bayesian methods were used to identify phylogenetic relationships and to estimate divergence times. Demographic histories were inferred using neutrality tests, mismatch distribution analysis, and coalescent simulation. A total of 112 haplotypes that clustered into three major groups were identified. The formation of these groups and their subgroups was dated to between the Pliocene and the late Pleistocene. In addition, we found that some groups underwent multiple extensive expansions. Species‐specific haplotypes were identified for each species, although these haplotypes phylogenetically intermixed. These results suggest that recent plateau uplifts and climatic oscillations might have caused the deep divergences observed within this genus. However, later range expansions probably blurred these divergences and possible species boundaries. Our results shed new light on the complex evolutionary history of the QTP alpine plants. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111 , 777–788.  相似文献   

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