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1.
Most of the estimated 70–80 species of New Zealand Gnaphalieae are endemic. Those of Anaphalioides , Ewartia , Helichrysum , Leucogenes , Rachelia and Raoulia belong to a putatively monophyletic group which is supported by analysis of nuclear ITS DNA sequences and is virtually confined to New Zealand. All species of Craspedia , Euchiton , Ozothamnus and Pseudognaphalium are excluded from this group. A phylogenetic analysis of 42 species of Gnaphalieae, using 57 morphological, anatomical and palynological characters, was conducted to test the monophyly of this group and to seek evidence of generic relationships. The analysis does not resolve basal relationships among the Gnaphalieae studied here. The putative monophyletic New Zealand group is not retrieved. Monophyly is supported for each of Euchiton , Leucogenes , the whipcord species of Helichrysum , the pulvinate species of Raoulia , and Raoulia subg. Raoulia (excluding the aberrant R. cinerea ), but not for Anaphalioides or Raoulia s.l. There are these two distinct groups in Raoulia s.l. but also a substantial number of isolated species. The sole New Zealand species of Ewartia is not a sister species to Australian Ewartia . The Australian species Ewartia planchonii is the sister species to Euchiton rather than to the other Australian species of Ewartia .  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 141 , 183–203.  相似文献   

2.
蒋天翼  陈志钊  陈曌  郑永利  陈昕  邓云飞 《广西植物》2023,43(10):1814-1827
为澄清映山红亚属(Rhododendron subg. Tsutsusi)内的系统关系问题,该研究选择杜鹃花属映山红亚属37种植物作为对象,其中29种为首次报道,通过扫描电镜观察其叶表皮显微特征。结果表明:(1)气孔器均为无规则型且均在远轴面。(2)根据叶片微形态特征将映山红亚属的种类分为杜鹃型(R. simisii-type)、岭南杜鹃型(R. mariae-type)、皋月杜鹃型(R. indicum-type)、崖壁杜鹃型(R. saxatile-type)及丁香杜鹃型(R. farrerae-type)5种类型。(3)杜鹃型植物的气孔器周边无或具间断的条形突起。(4)岭南杜鹃型植物的气孔器周围有多层条形突起环绕,保卫细胞两极不具T型加厚。(5)皋月杜鹃型植物的叶表皮保卫细胞两极具有T型加厚,与叶状苞亚属(Subg. Therorhodion)叶状苞杜鹃(R. redowskianum)的气孔器特征相似,推测其与叶状苞亚属具有一定的亲缘关系。(6)崖壁杜鹃型植物的叶表皮毛单一,多呈卷曲状,与其他类型有所不同且未见腺体。(7)丁香杜鹃型植物的叶表皮仅有腺体。(8)依据叶表皮微形态特征讨论了一些近缘种类的关系,如倾向于将背绒杜鹃(R. hypoblematosum)和千针叶杜鹃(R. polyraphidoideum)处理为独立的种,支持保留紫薇春(R. naamkwanense var. cryptonerve)作为南昆杜鹃(R. naamkwanense)的变种地位,不支持将腺花杜鹃(R. adenanthum)并入细瘦杜鹃(R. tenue)作异名处理等。该研究结果表明叶表皮显微特征在映山红亚属内物种划分上具有重要价值。  相似文献   

3.
利用扫描电镜技术观察了茶藨子属7个亚属12种植物的叶表皮微形态。结果显示:叶表皮细胞分为多边形和不规则形两种类型;垂周壁式样为平直—弓形、浅波形、深波形;叶表皮角质层多为光滑或较光滑,少有脊状纹饰或乳突状凸起;表皮毛分为单毛和腺毛;黑果茶藨子、水葡萄、臭茶藨子的叶表面均分布不同密度的盾状腺毛,支持将臭茶藨子系划分为臭茶藨子亚属;气孔器均为无规则型,形状为圆形或椭圆形,多数种类的气孔仅分布在下表皮。茶藨子属植物叶表皮微形态特征可为属内亚属划分及种间分类提供一定的依据。  相似文献   

4.
Icon-like diagrams are used to summarize the anatomical patterns observed in leaf cross sections of 30 taxa of Festuca subgg. Festuca and Leucopoa occurring in western North America. Measurements of four variables, notes on the degree of development and the position of sclerenchyma, along with distribution maps of 24 native taxa, are presented. Twenty-nine diagrams were created from the synthesis of at least ten leaf-section drawings based on five plants chosen from across the geographic range of each taxon (fewer suitable specimens were obtained for two taxa). A key based on data collected in this study allows identification of species in subg. Festuca. Geographic distribution is more reliable than leaf anatomy for separating taxa in subg. Leucopoa.  相似文献   

5.
The genus Mortoniodendron is distributed from southeastern Mexico to Colombia and contains about 18 species of trees and shrubs. The main goal of this study is to describe and compare the leaf architecture and the anatomy of 11 species of Mortoniodendron using cleared leaves and paradermal and transverse leaf sections. All of the species of Mortoniodendron share a simple lamina with an entire margin. The differences among the species include the venation pattern, the relative thickness and course of the secondary veins, the presence or absence of the intersecondary veins, the tertiary vein pattern, the number of branches in veinlets, and the marginal ultimate venation. The leaf anatomy is similar to other species of the Malvaceae s.l.: for example, mucilage cells are common in Mortoniodendron. There are unique attributes of the leaf architecture and anatomy, such as the eucamptodromous venation pattern of M. guatemalense, which facilitates the identification of the species. The species M. palaciosii, M. pentagonum, M. ruizii, M. uxpanapense, and M. sp. nov. share features that suggest that they are closely related.  相似文献   

6.
The leaf anatomy of 20 Alpinia species from China was investigated. Results show that there is interspecific variation in the structure of the leaf midrib and petiole which can be used for species identification. Adaxial hypodermis is present in the lamina in all species of subgenus Catimbium and absent from all species of subgenera Dieramalpinia and Aobolocalyx and Alpinia , excepting A. conchigera, A. galanga and A. aquatica , which appear to be closely allied in having subepidermal fibres in midribs and petioles, which are absent from the rest of the species.  相似文献   

7.
The rheophyte Dendranthema yoshinaganthum(Makino ex Kitam.) Kitam. is endemic to a region along the Naka River in Shikoku, Japan. Resembling other rheophytes that have adapted to environments along rivers, D. yoshinaganthumhas narrow leaves. In the native habitat of D. yoshinaganthumin Tokushima, Japan, natural hybridization with Dendranthema indicum (L.) Des Moul. has resulted in a species complex with conspicuous variation in leaf shape and, in particular, in leaf width. In this study, D. yoshinaganthum and hybrids with natural variation in leaf shape were cultivated under identical conditions and the anatomy of their leaves was examined. Variation in leaf width in the species complex was attributable, for the most part, to variation in the number of cells per leaf lamina and also, to some extent, to variation in cell size. This is the first report of natural variation in leaf width that is attributable to variation in both the size and the number of leaf cells.  相似文献   

8.
The leaf anatomy of Goniothalamus andersonii, G. macrophyllus, G. malayanus and G. velutinus from the peat swamps of Sarawak is compared. Sufficient anatomical differences exist to differentiate the four species. G. velutinus has many points of difference from the other three species and G. macrophyllus is readily identified by the presence of fibre-sclereids in the lamina mesophyll. G. andersonii and G. malayanus are similar to each other, but G. andersonii can be distinguished, in particular by the more pronounced multiple projections of the outer periclinal walls of the epidermal cells and the presence of thick and cutinised outer ends of the anticlinal walls of the epidermal cells.  相似文献   

9.
The structural causes of variation in leaf mass per area, and of variations in leaf structure accounted for by leaf habit and life form, were explored in a set of laboratory-grown seedlings of 52 European woody species. The leaf traits analysed included density, thickness, saturated mass/dry mass, and leaf nitrogen per mass and per area. Other traits described the anatomy of leaves, most of them relating to the lamina (proportions of palisade and spongy parenchymata, epidermis, air space and sclerified tissues, expressed as volume per leaf area, and per-cell transversal areas of epidermis and parenchymata), and another referring to the mid rib (transversal section of sclerified tissues). Across the whole set of species leaf mass per area was correlated with leaf density but not with thickness, and this was confirmed by taxonomic relatedness tests. Denser leaves corresponded with greater proportion of sclerified tissues in the lamina, smaller cells and lower water and N contents, but no relation was found with the proportion of air space in the lamina. Taxonomic relatedness analysis statistically supported the negative association of leaf density with saturated to dry leaf mass ratio. Thicker leaves also exhibited greater volume per leaf area and greater individual cell area in each of the tissues, particularly parenchyma. Mean leaf mass per area and leaf thickness were lower in deciduous than in evergreen species, but no significant differences in leaf density, proportion of sclerified tissues in the lamina or cell area were found between the two groups. Leaf mass per area was higher in trees and subshrubs than in shrubs and climbers-plus-scramblers, this rank being equal for leaf density and proportion of sclerified tissues in the lamina, and reversed for cell area. Given the standardised environment and ontogenetic phase of the seedlings, we conclude that variation in leaf structure and anatomy among species and species groups has a strong genetic basis, and is already expressed early in the development of woody plants. From an ecological viewpoint, we can interpret greater leaf mass per area across this species set as greater allocation to support and defence functions, as shown predominantly by species from resource-poor environments. Received: 16 August 1999 / Accepted: 29 March 2000  相似文献   

10.
11.
Ranunculus is a large genus with a worldwide distribution. Phylogenetic analyses of c. 200 species of Ranunculus s.l. based on sequences of the nrITS using maximum parsimony and Bayesian inference yielded high congruence with previous cpDNA restriction site analyses, but strongly contradict previous classifications. A large core clade including Ranunculus subg. Ranunculus, subg. Batrachium, subg. Crymodes p.p., Ceratocephala, Myosurus, and Aphanostemma is separated from R. subg. Ficaria, subg. Pallasiantha, subg. Coptidium, subg. Crymodes p.p., Halerpestes, Peltocalathos, Callianthemoides, and Arcteranthis. Within the core clade, 19 clades can be described with morphological and karyological features. Several sections are not monophyletic. Parallel evolution of morphological characters in adaptation to climatic conditions may be a reason for incongruence of molecular data and morphology-based classifications. In some mountainous regions, groups of closely related species may have originated from adaptive radiation and rapid speciation. Split decomposition analysis indicated complex patterns of relationship and suggested hybridization in the apomictic R. auricomus complex, R. subg. Batrachium, and the white-flowering European alpines. The evolutionary success of the genus might be due to a combination of morphological plasticity and adaptations, hybridization and polyploidy as important factors for regional diversification, and a broad range of reproductive strategies.  相似文献   

12.
The leaf and twig anatomy of 25 species of the genus Eriope were studied. The twig anatomy is very uniform apart from the level of formation of early layers of cork. Leaf anatomy shows considerable variation between the species, and this is correlated to some extent with the extreme habit range from trees to woody herbs. Characters of the lamina that show variation are: trichome type and frequency, cuticular markings, leaf dorsiventral or isobilateral, presence of adaxial stomata, presence of a hypodermis, number of layers of adaxial palisade mesophyll cells, occurrence of large bundles of phloem fibres at main veins, type of areolation and marginal venation. Petiole vasculature is simple and generally with either four distinct vascular bundles or two vascular arcs. The most xeromorphic species are usually woody herbs or sub-shrubs, and tend to have thick, isobilateral leaves with large bundles of phloem fibres and few hairs, or strongly dorsiventral leaves with a hypodermis and stomata in deep abaxial hair-lined depressions. The correlation of xeromorphic characters with environmental conditions is discussed. Leaf anatomy is of limited value in elucidating relationships within the genus.  相似文献   

13.
Comparative leaf anatomy of New Zealand and Tasmanian Inuleae (Compositae)   总被引:1,自引:0,他引:1  
Leaf anatomy is compared for 47 taxa of the tribe Inuleae (Compositae) from New Zealand and Tasmania. The taxa are tabulated according to their lamina structure. Noteworthy anatomical features are lamina type and grade of differentiation, stomatal position, epidermis and cuticle thickness, shape of palisade cells, number of bundle-sheath layers; presence or absence of sclerenchyma caps, water storage cells, secretory canals, abaxial collenchyma and protruding midrib. It is shown that leaf anatomy data provide characters which are taxonomically useful in classification of Inuleae.  相似文献   

14.
The nodal anatomy of Xanthophyllum is unilacunar with a single broad trace departing the cauline stele. The "stipular glands" or extra floral nectaries of some species are vascularized by bundles originating from the base of the leaf trace. Considerable variation exists among species in petiole vasculature with siphonosteles, steles with medullary bundles and simple, flat traces present. The lamina also shows variation in the presence or absence of a hypodermis, nature of vein sheathing, presence or absence of abaxial epidermal papillae, amount of intercellular spaces, and mature stomatal patterns which range from anisocytic and paracytic to those in which no subsidiary cells are discernible. Of nearly uniform occurrence throughout the genus are extraordinary tracheoid foliar idioblasts, which are confined to the veins in terminal or subterminal positions. The large amount of variation in leaf anatomy is shown to be taxonomically significant within the genus.  相似文献   

15.
Mediterranean perennial species are described as being sclerophyllous,or summer deciduous, or seasonally dimorphic. Field observationin the coastal maquis of Castelvolturno Nature Reserve, southernItaly, showed thatCistus incanus L. subsp. incanus is a seasonallydimorphic species as it develops brachyblasts with small leavesin summer, and dolichoblasts with large leaves in winter. Fieldbiometric data confirmed that winter shoots were 14-times longerthan those developed in summer and had many more leaves. Thearea of single winter leaves was five-times that of summer leaves.Anatomical leaf structure also changed with the season: winterleaves were flat while summer leaves had a crimped lamina whichwas partially rolled to form crypts in the lower surface. Leaveswere covered by considerably more trichomes in summer than inwinter. Stomata were uniformly distributed along the lower epidermisof winter leaves but were only present in the crypts of summerleaves. In summer leaves, a palisade layer was often found onboth sides of the lamina, the mesophyll cells were generallysmaller and the intercellular spaces were reduced. Winter leaveshad a dorsiventral structure and larger intercellular spaces.Seasonal dimorphism is generally reported to be an adaptationto summer drought. However, the morphology and anatomy of C.incanus L. subsp.incanus showed that the subspecies has notonly developed a strategy to survive summer drought, but hasevolved two different habits, one more xerophytic than the other,to optimize adaptation to the seasonal climatic changes occurringin Mediterranean environments. Copyright 2001 Annals of BotanyCompany Cistus, Cistus incanus L. subsp. incanus, climatic changes, leaf anatomy, leaf dimorphism, Mediterranean shrubs, phenology, seasonal dimorphism  相似文献   

16.
A study of leaf anatomy of 24 genera of Cunoniaceae was made. The prevailing petiole vasculature is a nearly complete, usually adaxially flattened, medullated cylinder with the flat dorsal segment separated from the ventral arc. Medullary and cortical vasculation in Codia, Cunonia, Geissois and Pancheria is correlated with an increase in leaf coriaceousness. Very few characters are uniformly found in leaves of all species; these are druse or prismatic crystals, bifacial mesophyll and unicellular and simple trichomes. In most species vein sheathing occurs. Characters of the lamina that show variation and are useful in generic delimitation are: trichome type, presence of a hypodermis, occurrence of mucilaginous cells, presence of specialized terminal veinlet cells, major and higher order venation patterns, vein sheathing type, and mature stomatal types. Stomata are of the anomocytic, paracytic or anisocytic types. Leaves of various cunoniaceous species of xerophytic environments exhibit a leathery texture, thicker cuticle, more intensive sclerification along the veins, a sclerified hypodermis, and an increase in the amount of vascular tissue per unit area. Leaf anatomy does not provide immediate clues toward elucidating the relationships of cunoniaceous genera.  相似文献   

17.
18.
The leaf anatomy of 22 Alpinia species from the Malay Peninsular was investigated. Results show that a combination of characters such as outlines of midribs, petioles, leaf margins and their relative sizes in transverse sections as well as the presence of hypodermal fibres in the lamina, midribs and petioles can be used in the identification of species. All four species of subsection Allughas possess similar characters such as the presence of abaxial and adaxial fibres in the midrib and petioles and the absence of hypodermis in the lamina while the reverse is true for all species of subsection Catimbium. Alpinia conchigera and A. galanga appear to be closely related while A. oxymitra is distinct from all the species studied.  相似文献   

19.
Blepharis (Acanthaceae) is an Afroasiatic genus comprising 129 species which occur in arid and semi-arid habitats. This is the only genus in the family which is reported to have some C(4) species. Blepharis ciliaris (L.) B. L. Burtt. is a semi-desert species with distribution in Iran, Oman, and Pakistan. Its form of photosynthesis was investigated by studying different organs. C(4)-type carbon isotope composition, the presence of atriplicoid type Kranz anatomy, and compartmentation of starch all indicate performance of C(4) photosynthesis in cotyledons, leaves, and the lamina part of bracts. A continuous layer of distinctive bundle sheath cells (Kranz cells) encircle the vascular bundles in cotyledons and the lateral vascular bundles in leaves. In older leaves, there is extensive development of ground tissue in the midrib and the Kranz tissue becomes interrupted on the abaxial side, and then becomes completely absent in the mature leaf base. Cotyledons have 5-6 layers, and leaves 2-3 layers, of spongy chlorenchyma beneath the veins near the adaxial side of the leaf, indicating bifacial organization of chlorenchyma. As the plant matures, bracts and spines develop and contribute to carbon assimilation through an unusual arrangement of Kranz anatomy which depends on morphology and exposure to light. Stems do not contribute to carbon assimilation, as they lack chlorenchyma tissue and Kranz anatomy. Analysis of C(4) acid decarboxylases by western blot indicates B. ciliaris is an NAD-malic enzyme type C(4) species, which is consistent with the Kranz cells having chloroplasts with well-developed grana and abundant mitochondria.  相似文献   

20.
The grass Alloteropsis semialata (R.Br.) Hitchcock is uniquein that both Kranz and non-Kranz leaf anatomy has been reportedin this species. The present study investigates Kranz formsof A. semialata collected from a single ecological niche. Theseplants exhibit morphological and anatomical differences withrespect to leaf area, stomatal size and stomatal distribution.Carbon dioxide and water exchange measurements in the two formsshow the expected pattern of higher photosynthetic rate andhigher water utilization efficiency associated with Kranz anatomy.No intermediate physiological response or anatomical form wasobserved in this sample. Alloteropsis semialata (R.Br.) Hitchcock, C3 photosynthetic, C4 photosynthesis, water utilization, leaf anatomy, Kranz anatomy  相似文献   

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