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1.
Scanning electron microscopy supported by light microscopic L-O analysis is used in a palynological study of the genus Trichipteris of the tree fern family Cyatheaceae. The spores of all but two of the 55 species are investigated and the results are related to previous findings for Trichipteris species in the literature. A perine layer consisting of a network of slender, smooth- or rough-textured interlocking strands with free ends uniformly characterizes the genus and is the same as the perine type previously reported in neotropical species of Sphaeropteris excluding the S. horrida group. The exine is analyzed both in spores which have not yet developed the perine layer and in spores whose perine has been removed by chemical treatment. Exine sculpturing shows great variation in the genus, ranging from essentially psilate to variously pitted (foveolate, foraminate), with topography ranging from plane to verrucate-tuberculate, and with the verrucae-tubercles themselves often variously pitted. In many instances, exine sculpturing types correlate with the infrageneric species groupings or affinities hypothesized by the recent monographers. In other cases, palynological characters offer new insight into species relationships that were previously unclear to monographers or that were interpreted differently on the basis of other characters. The exine sculpturing types reinforce the relationship evident between Trichipteris and neotropical Sphaeropteris on the basis of perine morphology.  相似文献   

2.
The pollen morphology of 29 species ofOdontites and related genera was examined by light and scanning electron microscopy. Three major pollen types differing fundamentally in exine sculpturing were found. In the parasitic tribePedicularieae retipilate sculpturing is the most widespread type representing a plesiomorphic character state from which the two other types are derived. Of these, reticulate sculpturing is confined toOdontites, whereas a complex retirugulate pattern was found only in the monotypic Near East genusBornmuellerantha. Within the retipilate and the reticulate major types eight minor types were distinguished based on the differential correlation of exine surface morphology, size, shape and amb form. The pollen data are generally well correlated with macromorphological features and furnish important taxonomic characters at the genus—as well as at the specieslevel.  相似文献   

3.
Nutlet sculpturing of 23Teucrium species belonging to six sections was studied. The nutlets of analysed species were characterized by the presence of the oil glands of various density. SectionTeucrium is well defined by very densely distributed trichomes and oil glands on nutlets. Trichomes on nutlets were absent in all other species, except inT. marum from sect.Chamaedrys. Sect.Polium is a homogeneous group, distinguished from the other sections. There are some similarities of this sect. with sect.Scordium. Species of sect.Chamaedrys are heterogeneous and overlap according to the surface sculpturing characters with the other sections. The significance of nutlet microcharacters as additional taxonomical markers in the infrageneric classification of the genusTeucrium is discussed.  相似文献   

4.
Nutlet sculpturing of 22 taxa ofScutellaria sect.Resinosa, representing 18 of its 19 species, and the monotypic genusSalazaria was studied by scanning electron microscopy (SEM). The nutlets of sect.Resinosa, while remarkably variable among themselves, differed from hypothetically closely related sections in lacking circumferential banding and sessile glands. Species could be grouped by surface sculpturing into seemingly meaningful phenetic clusters.Scutellaria potosina var.platyphylla was sufficiently distinct micromorphically so as to be elevated to specific status asScutellaria platyphylla comb. and stat. nov. The significance of nutlet microcharacters within sect.Resinosa is discussed, especially as compared to closely related sections. The genusSalazaria had nutlet sculpturing quite different from all taxa belonging to sect.Resinosa.  相似文献   

5.
The pollen morphology of Diosma and Coleonema of the taxonomically problematic subtribe Diosminae (Rutaceae) was investigated to determine its taxonomic relevance. Pollen of 26 of the 28 species of Diosma and of each of the eight species of Coleonema was investigated by LM, SEM and TEM. In pollen of Diosma the exine sculpturing is uniform, and only one pollen type, reticulate, could be distinguished. In contrast, exine sculpturing shows interspecific variation in Coleonema and three distinct types, striate, reticulate and perforate, could be discerned. Species groupings indicated by the pollen types suggest possible relationships between species within Coleonema and with other genera that were not previously apparent. Pollen data support macromorphological evidence that suggests the generic re-classification of the Diosminae.  相似文献   

6.
The aim of the present study is to describe the morphology and internal wall structure of Zingiber pollen. The pollen of 18 species of Zingiber was examined by light, scanning and transmission electron microscopy. In the sections Zingiber and Dymczewiczia (Horan.) Benth. the pollen grains are spherical with cerebroid sculpturing while in the section Cryptanthium Horan. the pollen is ellipsoid with spira-striate sculpturing. All species have a thin coherent exine and an intine consisting of a thick, radially channeled outer layer and a thin, finely granular inner layer. On the basis of pollen morphology it is proposed that the section Dymczeniczia is included in the section Zingiber. The structure of the pollen wall in Zingiber resembles that of Canna and Strelitzia in having a pollen wall offering an infinite number of germination sites.  相似文献   

7.
燕麦属颖果微形态特征及其分类学意义   总被引:1,自引:0,他引:1  
为探讨燕麦属颖果微形态特征的分类学意义,采用体视显微镜和扫描电子显微镜观察燕麦属27种颖果的微形态特征,结合分子系统发育证据分析其分类学意义。燕麦属颖果有纺锤形、倒披针形、椭圆形3种形状,条纹、棱纹、网纹3种纹饰。燕麦属颖果形状、纹饰和花柱基宿存模式具有有限的属下分类学意义,颖果大小和表面大毛密度具有种间鉴定价值,而颖果腹面形态、压扁方式、胚比不具有种间鉴定价值。大穗燕麦(Avena macrostachya Balansa ex Coss.Durieu)颖果纺锤形,条纹纹饰,隶属于燕麦属颖果微形态特征的变异范围。大粒裸燕麦(A.nuda L.)与普通栽培燕麦(A.sativa L.)颖果大小、形状及纹饰特征的差异支持将大粒裸燕麦作为独立种处理。燕麦属颖果大小、表面大毛密度、胚比变异幅度大,推测与分布区广幅的气候变异相适应,凹腹面颖果体积相对缩减,有利于颖果快速发育、成熟,推测与燕麦属植物在温带、寒带分布区适生期较短相适应。  相似文献   

8.
The pollen morphology of Adenandra Willd. (Rutaceae: Diosminae) was investigated to determine its taxonomic significance. Pollen of 27 of the 30 infrageneric taxa (representing 16 of the 18 species) was investigated by LM, SEM and TEM. Adenandra differs from all other Diosminae in having 4-colporate rather than 3-colporate pollen grains. This supports the alleged monophyletic status of the genus. Exine morphology and structure, however, is extremely diverse considering the size of the genus, with eight distinct pollen types and four subtypes being discerned. In some members the grains have uniform macroreticulate, striate or striato-reticulate sculpturing, whereas in others the poles have striate, striato-reticulate or reticulate-perforate sculpturing with various types of reticulate or rugulate sculpturing at the mesocolpia. Taxonomic groupings revealed by the pollen characters suggest elationships between taxa that were not previously apparent. It is suggested that evolutionary diversification among species of Adenandra is often more strikingly reflected by pollen morphology than by macromorphology, hence the eurypalynous state of the genus.  相似文献   

9.
Fifteen Eurasian and Australian species of Viscum L. were examined by light, scanning, and transmission electron microscopy. Pollen characters divide the species into two groups, each correlated with differences in habit and inflorescence structure: Group I (12 spp.) characterized by psilate or slightly sculptured exines and a non-uniform ektexine pattern and Group II (3 spp.) possessing highly sculptured (echinate, rodlet) surfaces and uniform ektexine patterns. Within each of the groups, pollen characters divide the species into several subgroups. Among Group I, species V. nepalense, V. heyneanum and V. ovalifolium are particularly close. The Group I species, V. trilobatum, is placed in its own subgroup primarily because of its uniform ektexine pattern—a unique feature among Asian and Australian Viscum. Of the three Group II species, V. album and V. alniformosanae are palynologically almost indistinguishable. Pollen of the Group II V. cruciatum, though exomorphologically similar to V. album, is closest ultrastructurally to the Indian V. trilobatum. Overall, the most common and probably basic pollen characters among the Eurasian and Australian species include: subprolate, rounded convex almost spherical shapes; tricolporate apertures, and non-uniform sculpturing and ektexine patterns. Oblate-spheroidal or prolate-spheroidal shapes, prominent sculpturing, and a uniform ektexine pattern are derived characters largely restricted to the Eurasian and Asian Group II species (V. album, V. alniformosanae, V. cruciatum).  相似文献   

10.
In the present study, seeds of 13 Oxytropis DC. species (including two latest synonyms) classified in subg. Oxytropis (sect. Dolichocarpon, sect. Chrysantha and sect. Eumorpha), subg. Euoxytropis (sect. Orobia) and subg. Phacoxytropis (sect. Protoxytropis, sect. Janthina and sect. Mesogaea) from Turkey were examined using light and scanning electron microscopy to evaluate the taxonomic relevance of macro- and micro-morphological seed characters. As a result of the study, species-specific characters have been determined. Seeds exhibit variation in size, shape, surface sculpturing pattern, hilum position and weight. Seeds ranged from 1.61 to 4.04 mm in length and from 1.02 to 2.56 mm in width. Five different seed shapes were recognised, as prolonged semielliptic, reniform, prolonged reniform, quadratic and cardiform, with a length to width ratio ranging from 1.02 ± 0.08 to 1.75 ± 0.27. Rugulate, rugulate–reticulate and lophate sculpturing patterns were observed in the studied species. According to the results, seed characters, such as the size (length, width and the length/width ratio), the shape, the surface sculpturing and the weight appear to have low taxonomic value in distinguishing subgenera, sections and species.  相似文献   

11.
The adults and egg of Habrophlebia antoninoi sp. n. are described and illustrated from material collected in southern Spain. Although the genitalia of the new species is characteristic of Habrophlebia, the chorionic sculpturing of the egg and the shape and venation of hind wings are unique among European members of the genus. A discussion of its relationships with other European species of Habrophlebia is included and a key to male imagines of European species of Habrophlebia is provided.  相似文献   

12.
Pollen of the two distylous species which make upLinum sect.Macrantholinum differs from that of other distylous species in the genus in being multiporate and in having much more modest differences in exine sculpturing between grains from long- and short-styled plants. Pollen morphology does not help in relating the two species to others in the genus but does support their retention in a separate section.  相似文献   

13.
14.
15.
Floral ontogeny is described in eight species of Sophora sensu lato, representing the Sophora group, as part of a comparative ontogenetic analysis of Polhill's eight groups of tribe Sophoreae, subfamily Papilionoideae. This tribe includes taxa having relatively unspecialized floral structure. Flowers have a five-lobed calyx, a corolla of five free petals, ten mostly unfused, identical stamens, and a carpel. Order of initiation is predominantly acropetal (except for the carpel): sepals, petals, outer stamens plus carpel, inner stamens. Order of initiation within each whorl is unidirectional from the abaxial side. Overlapping initiation among whorls occurs only in S. chrysophylla. Keel petals are slightly fused in six species, and wing petals are fused in 5. tomentosa. Two bird-pollinated species (S. chrysophylla, S. microphylla) lack the papilionaceous corolla of other species, and their petals are unusually long and lack wing sculpturing found in the others. Other floral differences among species mostly involve flower color, differing absolute or relative sizes among organs, and degree of reflexing of vexillum. All but S. davidii have a hypanthium, which develops very late, starting when the bud is about 5 mm long. The distinctions among species (petal size, degree of reflexed position of vexillum, petal sculpturing, color, anther shape, filament hairs, hypanthium presence, calyx lobing) tend to be expressed late in ontogeny.  相似文献   

16.
A new petalophthalmid mysid, Hansenomysis anaramosae n. sp., is described from specimens sampled with a suprabenthic sled in the Bellingshausen Sea (Southern Ocean). Hansenomysis anaramosae is clearly distinguishable from its closest congener, H. angusticauda Tattersall, by the carapace sculpturing, the rostrum produced into a spine-like process, the shape and armature of the antennal scale, eyeplate, and telson. This new species is the fourth Hansenomysis species described from the Southern Ocean. A key to these Antarctic species is presented.  相似文献   

17.
The first fossil species of the family Biphyllidae LeConte 1861, Diplocoelus probiphyllus n. sp., is described from Baltic amber. This species, which shows intermediate characters of antennae, sculpturing and pubescence between Diplocoelus Guérin-Ménéville 1844 and Biphyllus Dejean 1821, also suggests the presence of temperate mixed forests and a climate cooler than it has been until today hypothesised for Baltic Amber.  相似文献   

18.
The chiton fauna of Chile comprises 41 species, most of which inhabit shallow waters. The present paper gives a summary of all 14 chiton species reported from Chilean deep (bathyal to abyssal) waters, including some records that might be considered as doubtful. Leptochiton laurae n. sp. is formally established; it was formerly misidentified as L. americanus Kaas & Van Belle, 1985, but differs in the shape of the tail valve, less coarse sculpturing, in the girdle elements and radula armature. Two additional new species, Leptochiton sp. and Placiphorella sp., are discussed. For Leptochiton medinae Plate, 1899, a lectotype is designated. Tripoplax balaenophila (Schwabe & Sellanes, 2004) n. comb. is transferred from Lepidozona Pilsbry, 1892, due to coarse sculpturing in the central areas and multi-slit insertion plates. Leptochiton belknapi Dall, 1878 and Tripoplax cowani Clark, 2008 are reported from the study region for the first time. The majority of the Chilean deep-water polyplacophorans are associated with hard substrates (authigenic carbonates) near methane seeps. The present report raises the global number of chiton species inhabiting chemosynthetic environments from 10 to 18, including some overlooked literature records from other regions.  相似文献   

19.
20.
The pollen of seven species of Broussonetia (including Section Allaeanthus) and one species of Malasia were examined with light, scanning and transmission electron microscopy. The pollen of all species is diporate with slightly annulate pores, and scabrate exine sculpturing. The pollen is small and all species have a columellate wall structure. The closely related genus Malasia is similar to Broussonetia. The similarity of the pollen in Section Broussonetia and Section Allaeanthus suggests that Allaeanthus be retained in the genus Broussonetia.  相似文献   

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