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1.
在整理和鉴定浙闽薹草属Carex植物的过程中,发现福建薹草Cares fokienensis Dunn较早发表但并未被注意。通过文献查阅、模式标本研究和野外观察,认为闽清薹草C.minqingensis Z.P.Wang、九仙山薹草C jiuxiangshanensis L.K.Dai&Y.Z.Huang、苍绿薹草C.pallideviridis K.L.Chv(裸名)在果囊和雌花鳞片等鉴别性特征上与福建薹草并没有区别,应该处理为福建薹草的异名。  相似文献   

2.
BACKGROUND AND AIMS: In 1976 the monotypic genus Hellmuthia was placed in the Hypolytreae s.l., but was subsequently ascribed to the Mapanioideae, tribe Chrysitricheae, mainly because of the presence in Hellmuthia of two lateral, mapanioid-like floral scales with ciliated keels, the anatomy of the nutlet, the embryo and the inflorescence. Recently, based on cladistic analyses and supported by pollen ontogenetic evidence, Hellmuthia was transferred to a Cyperaceae, tribe Cypereae, clade mainly consisting of Ficinia and Isolepis. In this study, the floral ontogeny in Hellmuthia was investigated and compared with the floral ontogeny in Paramapania, with special attention for the floral scales. METHODS: Freshly collected inflorescences of Hellmuthia membranacea and Paramapania parvibractea were investigated using scanning electron and light microscopy. KEY RESULTS: In the conical 'spikelet' in Hellmuthia, proximal bracts occur, each axillating an axis with empty glume-like structures, or a reduced spikelet. Hence, it is a reduced partial inflorescence. In Hellmuthia, the stamen primordia originate before the primordia of the perianth-gynoecium appear. Moreover, a third adaxially positioned 'floral scale' was observed for the first time. The position and relative time of appearance of the floral scales in Hellmuthia are typical for perianth parts in Cyperoideae. The basal position of Hellmuthia within a clade of species with usually perianthless flowers, allows the presence of rudiments of a perianth in Hellmuthia to be interpreted as a primitive state. Development of the lateral 'scales' in Paramapania follows a different pattern. Therefore, it was decided that the lateral 'scales' in Paramapania are different from the lateral perianth parts in Hellmuthia. The pollen grains in Hellmuthia are cyperoid, with one polar and five lateral apertures, of which the membrane is covered with sexinous bodies. The pollen surface is granulate and perforate with microspines. CONCLUSIONS: The floral ontogeny in Hellmuthia occurs according to the general cyperoid pattern. The lateral scales in Hellmuthia are perianth parts, and they are not homologous to the lateral 'scales' in Paramapania.  相似文献   

3.
88 species and 20 subspecies ofCarex, altogether 94 taxa, occur in the area ofRechinger's Flora Iranica. Of these, 48 taxa, have an Euro-Siberian, 11 an Irano-Turanian and 35 a Central Asiatic distribution, the last including five species with connections to E. and tropical SE. Asia. The Saharo-Sindian element is missing. Endemic taxa are found in all groups. Eight taxa, endemic to the NW. Himalayas occur in the E. part of the area. The Euro-Siberian taxa are concentrated in the NW. of the area, but have connections to the east; similarly, Central-Asiatic taxa are concentrated in E. Afghanistan and N. Pakistan, but have connections to the west. Some Euro-Siberian taxa are widely distributed in the area, but avoid the most arid regions. The Irano-Turanian taxa are few and extend from Egypt through the area of Flora Iranica to Kazakhstan SSR and Central China.Dedicated to Hofrat Univ.-Prof. DrK. H. Rechinger on the occasion of his 80th birthday.  相似文献   

4.
对嵩草属(Kobresia)植物进行了初步的胚胎学研究。该属植物具假四合花粉(pseudomonad);药室内壁在二核花粉时期开始螺旋状加厚,花药表皮在花粉成熟时形成乳突;成熟花粉具三细胞。胚珠为倒生型,具厚珠心和双层珠被,珠孔由内珠被构成,珠柄的近基部向珠孔增生形成珠孔塞。胚囊的发育为蓼型,四分体线形排列,合点端大孢子发育成八核胚囊。受精后,胚乳核先于受精卵进行分裂,胚乳的发育为核型。胚的发育为柳叶菜型灯芯草变型。通过比较,嵩草属植物大小孢子的发育、胚珠的结构、胚囊的发育、胚乳的发育和胚的发育与莎草科中其它类群一致。所以,根据胚胎学资料,嵩草属及其近缘属应保留在莎草科中,不该另立为嵩草科。  相似文献   

5.
对嵩草属( Kobresia) 植物进行了初步的胚胎学研究。该属植物具假四合花粉(pseudomonad) ; 药室内壁在二核花粉时期开始螺旋状加厚, 花药表皮在花粉成熟时形成乳突; 成熟花粉具三细胞。胚珠为倒生型, 具厚珠心和双层珠被, 珠孔由内珠被构成, 珠柄的近基部向珠孔增生形成珠孔塞。胚囊的发育为蓼型, 四分体线形排列, 合点端大孢子发育成八核胚囊。受精后, 胚乳核先于受精卵进行分裂, 胚乳的发育为核型。胚的发育为柳叶菜型灯芯草变型。通过比较, 嵩草属植物大小孢子的发育、胚珠的结构、胚囊的发育、胚乳的发育和胚的发育与莎草科中其它类群一致。所以, 根据胚胎学资料, 嵩草属及其近缘属应保留在莎草科中,不该另立为嵩草科。  相似文献   

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西藏嵩草属(莎草科)的修订   总被引:5,自引:0,他引:5  
在标本观察和野外调查的基础上,对西藏的嵩草属Kobresia植物进行了分类学修订,共确认了36种和1亚种。更正了6个类群的学名,它们正确的名称是K. esenbeckii,K. fissiglumis,K. gammiei,K. littledalei,K. myosuroides ssp. bistaminata和K. vaginosa。有13个名称,即K. angusta,K. cercostachys var. capillacea,K. clarkeana,K. curticeps var. gyirongensis,K. deasyi,K. glaucifolia,K. hookeri,K. nudicarpa,K. prainii var. elliptica,K. seticulmis,K. stenocarpa,K. stenocarpa var. simplex和K. williamsii处理为异名,其中K. prainii var. elliptica,K. glaucifolia和K. stenocarpa var. simplex为新异名。发现了西藏分布的一个新记录种密穗嵩草K. handel-mazzettii。还收录了最近发表的假钩状嵩草K. pseuduncinoides和阔鳞嵩草K. woodii。此外,重新编制了西藏嵩草属分种和亚种检索表,并较为详细地登记了各类群在西藏的分布地点。  相似文献   

9.
青海嵩草属(莎草科)的修订   总被引:1,自引:0,他引:1  
根据最新的研究结果修订了青海嵩草属植物的分类,确认了14种3亚种。通过对大量标本和文献的研究,澄清了《青海植物志》嵩草属中存在的分类学问题。门源嵩草、窄果嵩草、玉树嵩草和藏北嵩草等4种,分别归并在眠山嵩草、喜马拉雅嵩草、线叶嵩草和赤箭嵩草中;其中门源嵩草和玉树嵩草为新异名。青海产的嵩草和矮生嵩草,应该为二蕊嵩草和高原嵩草。短轴嵩草的学名更正为K.vidua。弧形嵩草在青海没有分布,文献中的记载可能为囊状嵩草的错误鉴定。此外,青海的嵩草属增加了2个类群,匍茎嵩草和夏河嵩草。  相似文献   

10.
Scanning electron microscopy (SEM) was used to examine achene epidermal features of nine Carex species within sections Vesicariae and Lupulinae. Two major epidermal features are recognized in this study: the epidermal layers with one or two primary silicon bodies in each cell and the absence of any primary silicon body. Comparative data of achene morphology using SEM, and evidence compiled from previous investigations, support the placement of Carex retrorsa within section Vesicariae.  相似文献   

11.
KUKKONEN  I. 《Annals of botany》1967,31(3):523-544
The vegetative anatomy of 18 (19) Uncinia spp. (Cyperaceae-Cariceae)including representatives of most taxonomic subdivisions wasstudied to determine the range of variation in certain anatomicaland morphological characters of the vegetative organs withinthe genus. The two South American species U. erinacea and U. kingii differfrom all others, the former in having a closed cylinder of sclerenchymain the culm, and the latter a grooved culm. The three tall SouthAmerican spp., U. brevicaulis, U. hamata, and U. phleoides var.trichocarpa, are characterized by adaxial intercostal fibrestrands in the leaves, and in this respect show affinities withtall New Zealand species, U. sinclairii and U. uncinata. Thelast species does not have the intercostal strands. The muchsmaller U. tenuis from S. America resembles, in the size andshape of transverse sections of leaf and culm, a group of speciesfrom New Zealand comprising U. angustifolia, U. egmontiana,and U. rupestris. To these could be added U. banksii, U. hookeri,and perhaps also U. tenella, although the last two spp. exhibitsome distinctive characters in the transverse section of theleaf and also in the leaf epidermis in surface view. No exactcounterpart to the Australian and New Zealand spp. U. divaricata,U. riparia, U. rubra and U. scabra was found amongst the S.American material. This group of spp. is distinctive, for example,because of the triangular or irregularly triangular shape oftransverse sections of the culm and the large amount of sclerenchymain transverse sections of the leaf. The range of structural variation appears to be particularlywide in the S. American spp., which represent two extreme typesin the shape of the leaf in transverse section. The other talland small species have their respective counterparts in eacharea, although they are more profusely represented in New Zealandthan in America, and therefore show a correspondingly greaterrange of structure.  相似文献   

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邓德山 《广西植物》2002,22(2):116-120
以国产莎草科扁穗苔属 ( Blysmocarex cyperaceae)分布区内 30个居群硅酸体系统分析结果 ,结合植物形态学和植物生态地理学特征 ,深入探讨了广义的大花扁穗苔复合种 ( Blysmocarex macrantha complex)内类群系统演化与生境地理之间的关系。认为大花扁穗苔由 3个近缘的水平地理替代亚种构成 :subsp.macrantha、subsp.nudicarpa( Y.C.Yang) D.S.Deng、subsp.stolonifera( Wang ex Li) D.S.Deng;在地理空间上此三者具有较为明显的水平地理空间替代性。同时 ,认为 Ivanova( 1 939)建立扁穗苔属是具有合理性的  相似文献   

15.
Schoenus ferrugineus andS. nigricans have restricted distributions in Sweden and are almost exclusively confined to calcareous fen habitats. AtS. nigricans sites,S. ferrugineus is usually also present, and hybrids are frequently found. In this report, I used allozymes to estimate the amount of gene flow between the two species, and to compare the partitioning of genetic diversity in each of them. Thirteen loci were analysed at eight different enzyme systems. Seven loci were variable between or within the species. The two species had completely different alleles at two of the seven variable loci, whereas there was overlap at five loci. In all, 22 different alleles were found. Six of these alleles were confined toS. nigricans, and five alleles were confined toS. ferrugineus. Nei's genetic identity was 0.55.—InS. ferrugineus, three loci (23%) were polymorphic, and the average number of alleles per polymorphic locus was 2.0 (each polymorphic locus had two alleles). InS. nigricans, three loci (23%) were polymorphic, and the average number of alleles per polymorphic locus was 2.3.—The proportion of genetic diversity due to variation among sites (G ST) was fairly similar in the two species, mean over loci = 0.12 inS. ferrugineus and 0.15 inS. nigricans. However, the proportion of genetic diversity due to variation among individuals within sites (G IS) differed markedly between the two species, mean over loci = 0.54 inS. ferrugineus and 0.17 inS. nigricans. Accordingly, there was a much higher individual heterozygosity inS. nigricans than inS. ferrugineus. — Most hybrids were interpreted as F1 hybrids. However, a small proportion, 0.5–1.6 %, were Fn hybrids or back-crosses.—On the Swedish mainland, all former occurrences ofS. nigricans are extinct, but viable hybrids are still present at a few sites in southernmost Sweden.  相似文献   

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The origin of the orthotropic aerial shoot from the plagiotropic, horizontal rhizome of Carex arenaria L. (Cyperaceae) was studied. A previously proposed adnation or fusion of the first internode of the orthotropic shoot and the fourth internode of the plagiotropic shoot could not be anatomically confirmed. The rhizome branches sympodially and the point of branching results from intercalary meristematic activity in the plagiotropic shoot.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 146 , 145–151.  相似文献   

18.
Patterns of cytoskeletal organization during distinct polarizations that characterize pollen development in the sedge Carex blanda (Cyperaceae) were studied by correlated methods of immunohistochemistry and confocal and transmission electron microscopy. As is typical of the family Cyperaceae, Carex produces a unique pollen type known as a pseudomonad in which all four microspores of the tetrad are enclosed within the wall of a single pollen grain. Only one member of the tetrad is functional and the other three abort. The pseudomonads are precisely oriented in the locule with the functional microspore in the wide abaxial portion of the wedge-shaped cytoplasm adjacent to the tapetum, and the degenerative microspores are packed tightly in the pointed adaxial portion. A unique sequence of post-meiotic developmental events reflects both intracellular and intercellular polarity. Development includes: (1) random placement of tetrad nuclei in the coenocytic sporocyte after meiosis, (2) interrupted cytokinesis resulting in a tetrad of nuclei that migrates as a unit into the narrow adaxial tip, (3) completion of unequal cytokinesis and centering of the functional nucleus in the wide abaxial portion of the microsporocyte via a radial array of microtubules and microfilaments, (4) unequal mitosis resulting in a small generative cell at the proximal surface of the functional microspore (adjacent to the abortive microspores), and (5) recentering of the vegetative nucleus in the abaxial cytoplasm via a radial cytoskeletal array.  相似文献   

19.
Schoenoplectus americanus is a model organism for studying ecological and ecosystem responses of salt marsh plant communities to global climate change. Here we characterize 16 microsatellite loci in S. americanus to facilitate studies on the genetic basis of phenotypic responses to changing climate conditions such as elevated atmospheric carbon dioxide. Most loci also amplified in the morphologically similar sister species, Schoenoplectus pungens. Five loci exhibited species‐specific alleles or distinct allelic size distributions that discriminate S. americanus from S. pungens.  相似文献   

20.
We investigated the inflorescence structure of Rhynchospora following the methodology and terminology of Troll's school, with the objective of providing a characterization of the inflorescence suitable to evaluate the processes responsible for the diversity observed. Homogenization of inflorescence structures may occur fully or partially. In the first case, all branches of the inflorescence are homogeneous, while in the later, distal and proximal parts of the inflorescence bear homogeneous branches, but in the middle portions of the inflorescence non-homogeneous branches exist. Other characters leading to different forms of inflorescences are branching degree, internode elongation along the main axis of the synflorescence, degree of epipodium elongation of distal paraclades, development of bract and prophyll, and development of prophyllar paraclades. We identified three main types of inflorescences: (1) partially homogeneous paniculodia, (2) partially homogeneous capitate heads, and (3) a fully homogeneous capitate head. Within the first type, four subtypes were also recognized. Finally, we discuss how these processes can operate to produce the variation of the inflorescence shape.  相似文献   

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