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1.
对嵩草属27种(亚种)植物秆的解剖学研究证明,嵩草属植物秆的解剖学性状具有系统学意义.在该属中,秆的横切面外形为三角形、圆三角形、圆形或扁圆形.在横切面上分为2个区域;外部区域包括绿色组织、外韧维管束和气腔,内部区域为薄壁组织或其碎裂形成空腔.秆表皮的横切面观和表面观均与叶的下表皮相似.以上特征与莎草科其它类群植物秆的解剖特征一致,不支持将嵩草属和其近缘属另立为嵩草科.同时,秆的解剖学特征可以做为某些在外部形态上难于区分的种之间的分类依据.  相似文献   

2.
Leaf anatomy of the Pittosporaceae R. Br.   总被引:1,自引:0,他引:1  
WILKINSON, H. P., 1992. Leaf anatomy of the Pittosporaceae R. Br. An anatomical study of the leaves of 58 species representing all nine genera has been made. The anatomical characters found to be of most use in distinguishing taxa are: in surface view-cuticular architecture as seen with the SEM, stomatal outline, occasionally stomatal density, presence/absence of hairs, hair type in adult leaves; in transverse section-petiole/midrib outline, midrib number of vascular bundles and number of secretory ducts, adaxial epidermis in 1/2 layers, dimensions of adaxial epidermal cells, thickness of outer wall of adaxial epidermis, occasionally chlorenchyma interrupted/not interrupted above the midrib vascular tissue in Pittosporum species; leaf margin.  相似文献   

3.
The epidermis and internal structure of 103 species and 8 varieties of conifer leaves belonging to 37 genera of 7 families have been comparatively investigated. The anatomical characters of leaves of all the genera (or sections) studied are described systematically and a key to the genera (or sections) is also presented. It is shown that in order to identify at the genus level, the leaf types of LaubenFels’ may be used as the primary characterization. And it can also be seen that the following characters which are relatively constant at the genus level provide an important basis for identification: the epidermal structure, the presence or absence of hypodermis, the degree of differentiation of mesophyll, the occurrence of vascular bundle sheath or endodermis, the transfusion tissue type, the number and relative spatial position of vascular bundles, the number and distribution of resin canal and the presence of sclereid or sclerenchyma. The genera of Cupressaceae (except for Juniperus and Sabina) are of scale leaves (Leaf type-III) with little differences in structural characters. It’s difficult to distinguish them from each other. In addition, some problems concerning the significance of the resin canal, the endodermis with Casparian-strip, the sclerenchyma and the vascular bundle in identificationare here also discussed.  相似文献   

4.
WILKINSON, H. P., 1988. Leaf anatomy of the Menispermaceae tribe Tiliacoreae Miers . An anatomical study of the leaves of 25 species belonging to 12 of the 19 genera has been made. The anatomical characters found to be of the most use in distinguishing taxa or groups of taxa are: in surface view–stomatal outline, stomatal density and distribution, subsidiary cell or surrounding cell patterns, presence /absence of hairs; in transverse sections–dimensions of adaxial epidermal cells, morphology of spongy mesophyll, midrib outline, number and distribution of vascular bundles, presence/absence of an upper pulvinus, presence/absence of sclereids in the upper pulvinus, presence/absence of secretory sacs, crystal type and distribution.  相似文献   

5.
Among the subgenera of the genus Carex, the subgenus Indocarex has been seldom studied in any respects, Its systematic position and its subdivision are still disputable. Leaf anatomy of 14 species in the subgenus lndocarex from China was studied. The anatomical characters are proved to be systematically valuable. (1) Characters of lamina transverse section: All leaves of these 14 species are dorsiventral. The outline mostly V-shaped, occasionally flat or nearly flat, with adaxial lateral rib in each half of lamina and some of them flanged. The cells of adaxial surface larger than those of abaxial surface, and the epidermal cells over veins usually smaller than others. Air-cavities between vascular bundles are well developed, and bulliform cells also well developed in most taxa. The vascular bundles are collaterai, bundle sheaths double-layered, and the outer sheath parenchymatous and the inner sheath fibrous. (2) Characters of lamina epidermis: The shape of the cell on both surfaces is generally rectangular, and the anticlinal wall of epidermal cell sinuous; stomata is paracytic, elliptic to oblong, rarely sub-circular; prickles occur on adaxial surfaces of certain species; papillae are only obvious on abaxial surface of C. moupinensis Franch. The characters of transverse section and epidermis of leaf blades of these 14 species differ from each other to certain degree, and closely related species are similar in anatomical characters. The anatomical characters of lamina are of value for classification at specific and sectional level of the subgenus Indocarex. Despite of the variation of these characters among species, a certain num ber of characters appears to be shared by the members of the subgenus, and some of the common characters are primitive. In addition, some gross morphological characters are common and primitive also. Therefore, the subgenus Indocarex may be primitive in the genus Carex. The anatomical and morphological characters of C. scaposa C. B. Clakre and C. densifimbriata Tang et Wang ex S. Y. Liang are distinct. The two species and their allies should be treated as section instead of subsection. The three species in the sectionPolystachyae share some anatomical characters and comprise a coherent group.  相似文献   

6.
苔草属复序苔草亚属十四种植物叶片的解剖学研究   总被引:2,自引:0,他引:2  
选择中国复序苔草亚属6组4亚组的代表植物14种,进行了叶片解剖学研究,观察了其横切面 和表皮特征,证明上述特征在各类群之间存在差异,具有一定的系统学意义。这14种植物叶片的横切 面和表皮都具有一些原始的性状,表明复序苔草亚属中的植物可能在苔草属中是较原始的。在所观察 的植物中,Sect.Polystachyae植物叶片解剖学特征比较一致,说明此组的建立比较合理;而Sect.Indicae 组已有明显分化,尤其是Carex scaposa C.B.Clarke和C.densifimbriata Tang et S.Y.Liang 与其它植物明显不同,而且其外部形态特征在复序苔草亚属中也比较独特,因此赞成将它们及其近缘类群做为一个组而非亚组。  相似文献   

7.
Anatomical features of basal leaves, pedicels and tepals of 22 species of Gagea belonging to four sections (Platyspermum, Plecostigma, Gagea and Didymobulbos) are investigated. Anatomical characters are mapped onto a molecular phylogenetic tree and their evolution is evaluated. The systematic importance of the anatomical characters is discussed. Anatomical characters are more systematically useful in the Irano‐Turanian taxa than in Euro‐Siberian taxa. The presence of collenchyma and/or sclerenchyma and the pentagonal outline of the transverse section of the basal leaf is found in Irano‐Turanian taxa of section Platyspermum and is mostly absent in Euro‐Siberian taxa. A diagnostic key based on combined anatomical characters is provided. The level of variation in anatomical characters is greater in the basal leaf than the pedicel and lowest in the tepals. Convergent evolution in anatomical characters is associated with ecological shifts between sunny, open, dry habitats and closed, humid habitats. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 164 , 155–177.  相似文献   

8.
木犀属植物叶柄的比较解剖学研究   总被引:1,自引:0,他引:1  
对木犀属(Osmanthus)26种植物叶柄的解剖结构进行了研究.结果表明,木犀属植物叶柄的解剖特征存在比较丰富的变异,叶柄横切面形状有3种类型(U型、V型、Y型),周缘波状、浅波状或近平滑;表皮毛有或无;维管束一般为1大2小,维管束轮廓在种问变异丰富,维管束类型有周韧、近周韧、外韧3种;小叶月桂、牛矢果、厚边木犀、美洲木犀叶柄中央具髓腔,部分种叶柄有硬化细胞或石细胞存在.木犀属植物叶柄的解剖结构特征比较稳定,可作为该属的分种特征.  相似文献   

9.
10.
中国广义当归属及其相关类群的叶柄结构研究   总被引:1,自引:0,他引:1  
对中国38种广义当归属及其相关类群植物的叶柄进行了比较解剖学研究,考察了其横切面形状、髓腔的有无、周缘变化、厚角组织的形状和数目,以及维管束的数目和排列等基本特征,为该类群的分类鉴定和系统进化研究提供解剖学依据。结果表明:上述特征呈现出丰富的多样性和良好的种内稳定性,说明叶柄解剖学特征具有重要的分类学意义。综合上述特征,将广义当归属植物及其相关类群的叶柄划分为4个类型:中空环状类型(Ⅰ)、Φ形维管束型(Ⅱ)、U/V形维管束型(Ⅲ)、同心圆形维管束型(Ⅳ)。依据各类型的结构特点,认为该类群叶柄结构可能的演化关系为:实心叶柄是次生类型,中空环形叶柄(单轮环形维管束)相对原始,Φ形维管束型叶柄是过渡类型,而U/V形维管束型和同心圆形维管束型叶柄是相对高级的演化类型。  相似文献   

11.
Aizoaceae is one of the most important and widespread succulent plant families in both tropical/subtropical regions and arid zones. In this study, 27 species were collected from various floristic regions in Egypt, Kingdom of Saudi Arabia and cactus farms (Kalupia – Egypt). The morphological characteristics of every taxon were recorded. The important morphological features included: the number of leaves per plant; leaf types; leaf position (cauline or radical; the latter indicates leaves arising from, or near, the roots); leaf arrangement; petiolate or sessile leaves; leaf sheath present or absent; leaf shape; leaf margin; leaf tip; presence of leaf ‘window area’; leaf texture; and presence of white or dark miniscule dots (white miniscule dots from calcium carbonate and dark miniscule dots from tannin sacs). The investigated anatomical features were as follows: shape of the transverse section; the type of epidermal cells; the presence of large epidermal cells (bladder cells); presence of papilla and simple hairs; presence of tannin sacs; shapes of calcium oxalate crystals; shape of the xylem vessels; and the presence of Kranz unit (the unit that constitutes the vascular bundle/s, parenchyma sheath, and surrounding mesophyll) or collenchyma sheath. All data were recorded in a data matrix (as either text or numerical data), which was used to construct the identification key and phylogeny tree using a multi-variate statistical package. The results of our analysis may open the possibility of using the morphological and anatomical features of leaves to distinguish between the subfamilies, genera, and species of Aizoaceae.  相似文献   

12.
The anatomy and morphology of leaves in Carex have the potential to be taxonomically useful. However, studies on the variability of leaf characteristics in the genus are sparse. Researchers therefore risk using leaf anatomical characters without the knowledge of whether they are consistent in a species. We examined 22 qualitative and seven quantitative leaf anatomy characters from transverse leaf sections to test their consistency across 11 Carex spp. The characters were clearly described and primarily microscopic. Some characters were found to exhibit high levels of intraspecific variation, whereas other characters exhibited high levels of consistency in a species, including the shape of the leaf section, the density of papillae and the size of epidermal cells. Caution must be applied when choosing leaf anatomy to delimit taxa because of the intraspecific variability found in some characters, but sufficient numbers of invariant characters exist to provide useful taxonomic separation. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 172 , 371–384.  相似文献   

13.
We aimed to describe and analyse the morphological, anatomical and micromorphological traits of 36 Turkish orchids representing 12 genera (e.g. Anacamptis, Cephalanthera, Dactylorhiza, Orchis, Serapias) in detail and analyse their usability for solving phylogenetic and taxonomic issues. We applied UPGMA cluster analysis to anatomical, morphological and micromorphological characters such as root tubers, leaf and flower structures, pit, sclerenchymatic sheath, vascular bundle shape, crystal and starch, exodermis and endodermis structure, stomata type, bulliform cells in roots, shoots and leaves, surface structures like papillae, hairs and ornamentation on flower parts, leaves, fruits and seeds. Furthermore, in a phylogenetic framework, we analysed nuclear ribosomal ITS diversity in the same orchid species belonging, and in a combined Bayesian phylogenetic analysis based on anatomical, morphological, micromorphogical and ITS data we confirmed the usefulness of multiple data sets for effectively assessing taxonomically critical orchids. In the combined analysis, all genera were resolved as monophyletic with topologies congruent with recently published more thorough molecular phylogenetic reconstructions, while the trees obtained by seprately analysing the ITS and the anatomical, morphological, micromorphogical data were less resolved and partly inconclusive.  相似文献   

14.
This study concerns the evaluation of leaf anatomical characteristics of the closely related genera Matricaria (4 taxa) and Tripleurospermum (14 endemic taxa, 15 accessions) in Turkey using cluster analysis (CA) and principal component analysis (PCA). All taxa have the same basic leaf structure composed of lower and upper epidermis including anomocytic or anomocytic-anisocytic stomata, parenchymatic mesophyll, and vascular bundle. Statistically significant differences based on ploidy level have been found without generic delimitation. The differences mainly concern stomatal length and the relative size of the vascular bundle. These anatomical characters can be used to distinguish diploid from polyploid taxa of the genera.  相似文献   

15.
This study investigated the leaf structure of Bromelia and its importance for understanding the evolution of Bromelioideae (Bromeliaceae). Because of the scarcity of informative molecular characters in Bromeliaceae, this study evaluates the relevance of anatomical characters for the taxonomy and phylogeny of Bromelia and the subfamily Bromelioideae. Anatomical studies in monocots have shown that the combined application of anatomical and external morphological characters from leaf structure can improve the taxonomic delimitation of species, genera and subgenera, and is very informative for inferring phylogenies. The current study analyzed the leaves of 27 species of Bromelia and found that the most important characters for the systematics of this group are the occurrence of a water storage hypodermis, the number of stalk cells of peltate scales, the presence of a ribbed abaxial surface, the occurrence of palisade parenchyma on the adaxial side, the shape of the cells that surround the air lacunae, the presence of raphides and secretory channels, and the occurrence of fibrous extensions on the bundle sheath on minor veins. Combining our results with those described for the family, we made a list of the anatomical characters that can be used in phylogenetic studies of Bromelioideae.  相似文献   

16.
费菜和长药八宝叶形态结构及其与耐旱性关系的研究   总被引:2,自引:0,他引:2  
利用光学显微镜观察比较了费菜(Sedum aizoon L.)和长药八宝(S. spectabilis Boreau)的叶表皮形态及解剖结构,并对其进行不同程度的水分胁迫,研究干旱逆境条件对其叶片显微结构的影响。结果表明:两种景天的叶形态、解剖结构与耐旱性之间存在较密切的相关性。两种植物成熟叶均具较薄的角质层和发达的储水组织,叶肉组织中没有栅栏组织和海绵组织的明显分化。二者的维管组织较发达,且具较发达的孔下室,维管束周边发现一些吸水能力较强的异细胞,这些特征是植物耐旱的关键。  相似文献   

17.
MIDDLETON, D. J., A systematic survey of leaf and stem anatomical characters in the genus Gaultheria and related genera (Ericaceae). Leaf and stem anatomical characters of 123 species within the Gaultheria group of genera of the tribe Andromedeae are surveyed. A number of characters show considerable variation within a species which limits their taxonomic use. Other characters such as marginal sclerenchyma and, to a lesser extent, the hypodermis, the presence of adaxial stomata, the presence of free fibres and the pith type were of more taxonomic interest. These characters are discussed in relation to the generic and infrageneric classification of the group.  相似文献   

18.
Previous anatomical studies have been restricted to the foliar aspects of Pilocarpus. However, no anatomical studies analyzing the foliar aspects of Pilocarpus in relation to related genera have been carried out. Therefore, the aim of this study was to identify characters for future taxonomic and phylogenetic studies in Rutaceae, particularly in Pilocarpus, and to discuss the characteristics associated with the simple or compound leaf condition for the group. The petiole and the leaf blade of 14 neotropical Rutaceae species were analyzed, and the following characteristics were observed in all leaves studied: stomata on both surfaces; secretory cavities, including mesophyll type; camptodromous?Cbrochidodromous venation pattern; and free vascular cylinder in the basal region of the petiole. Additional promising characters were identified for future taxonomic and phylogenetic studies in the Rutaceae family, especially for the Pilocarpus genera.  相似文献   

19.
20.
A comparative study of leaf architecture and anatomy of 42 species of Bernardia and other genera related of Acalyphoideae was undertaken to identify characters that support infrageneric and specific delimitation. Thirty variable foliar architectural and anatomical characters were studied. Some characters are consistent (e.g., venation pattern, secondary and tertiary vein arrangement, presence or absence of agrophic veins, type of areoles, bundle sheath cell type, presence or absence of fibers in the mesophyll, trichome type, stomata location, and type of crystals), and characterize genera. In addition, foliar character distribution within Bernardia supports the most recent infrageneric classification.  相似文献   

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