Leaf anatomical studies in thePortulacaceae (Centrospermae) with regards to photosynthetic pathways

A total of 112 species in 18 genera in thePortulacaceae were investigated anatomically for the presence or absence of the chlorenchymatous bundle sheath cells around the vascular bundles: C4 or Kranz anatomy. Twenty species in only one genus,Portulaca L. of all the taxa investigated possesses the C4 or Kranz anatomy. All others have the C3 anatomy.     

Comparative vegetative anatomy and classification of Diseae (Orchidaceae)

The leaf, stem, root, tuber and dropper anatomy of the orchid tribe Diseae (including the subtribes Satyriinae, Disinae, Brownlecinac, Huttonaeinae and Coryciinae) is reviewed. The study is largely based on investigations of 123 species, and data from several previous publications have also been incorporated. Two characters were identified as being taxonomically valuable: (1) the presence of sclerenchyma caps associated with leaf vascular bundles, and (2) the degree of dissection of the siphonostele of the tuber (‘polystelic’ or ‘monostelic’). The phylogenetic analysis shows that anatomical characters do not change the basic structure of a cladogram that is based on morphological characters. The taxa of Diseae are discussed on the basis of anatomical data. Subtribes Satyriinae (excluding the anatomically unusual genus Pachites), Brownleeinae, Huttonaeinae, and Coryciinae are uniform in. critical anatomical characters. However, subtribe Disinae is rather diverse in vegetative anatomy. Disa sect. Micranthae differs from the rest of the genus in its leaf anatomy. The occurrence of foliar sclerenchyma bundle caps and ‘polystelic’ tubers supports the incorporation of Herschelianthe in Disa sect. Stenocarpa.     

Comparative vegetative anatomy and classification of Diseae (Orchidaceae)

The leaf, stem, root, tuber and dropper anatomy of the orchid tribe Diseae (including the subtribes Satyriinae, Disinae, Brownlecinac, Huttonaeinae and Coryciinae) is reviewed. The study is largely based on investigations of 123 species, and data from several previous publications have also been incorporated. Two characters were identified as being taxonomically valuable: (1) the presence of sclerenchyma caps associated with leaf vascular bundles, and (2) the degree of dissection of the siphonostele of the tuber ('polystelic' or 'monostelic'). The phylogenetic analysis shows that anatomical characters do not change the basic structure of a cladogram that is based on morphological characters. The taxa of Diseae are discussed on the basis of anatomical data. Subtribes Satyriinae (excluding the anatomically unusual genus Pachites), Brownleeinae, Huttonaeinae, and Coryciinae are uniform in. critical anatomical characters. However, subtribe Disinae is rather diverse in vegetative anatomy. Disa sect. Micranthae differs from the rest of the genus in its leaf anatomy. The occurrence of foliar sclerenchyma bundle caps and 'polystelic' tubers supports the incorporation of Herschelianthe in Disa sect. Stenocarpa.     

Subterranean axes in tribe Diurideae (Orchidaceae): Morphology,anatomy, and SYSTEMATIC SIGNIFICANCE

The morphological and anatomical nature of perennating storage organs of the predominantly Australasian orchid tribe Diurideae (Orchidoideae: Orchidaceae) as well as anatomical concepts in tribes Orchideae and Diseae of Orchidoideae have been problematic for 150 yr, reflected in conflicting or vague terminology and questions about polystely and even monophyly of Orchidoideae. From a representative survey of underground organs of 145 species in 37 ingroup genera (Diurideae) and two outgroup genera (Spiranthes and Disa), the so-called “root-stem tuberoids” are here interpreted as root tubers (except for the stem tubers of Rhizanthella) borne on either droppers or stolonoid roots. All root tubers examined are bounded by a 1–4 layered velamen and exodermis, whereas droppers and stolonoid roots may have velamen-exodermis or a simple epidermis depending on the taxon and often bear multiseriate or uniseriate trichomes associated with mycorrhiza (as do roots of some taxa). The “polystely” reported in tubers of many Orchideae also occurs in tubers of many Diurideae but represents only dissection of the siphonostele into 2–13 traces. Cladistic analyses of data show extraordinarily high levels of homoplasy in characters related to root, dropper/stolonoid root, and tuber, so that these characters alone are of limited usefulness.     

Taxonomic, evolutionary and ecological implications of the leaf anatomy of rhizomatous Iris species

The leaf anatomy of the rhizomatous Iris species with ensiform leaves and the related genera Pardanthopsis and Belamcanda is described. Their isobilateral leaves may or may not have a pseudo-dorsiventral structure. Variable characters of their leaf blades include: outline in transverse section, height and shape of papillae, form and structure of stomata, transverse section outline of marginal fibre strands and sclerenchy matous inner bundle sheath at phloem and xylem poles, forms of mesophyll arrangement, mesophyll structure and air canals, vascular bundle arrangement and the detailed structure of the larger vascular bundles, distribution of tannin, size and distribution of crystals. The taxonomic and ecological significance of these characters has been evaluated.
The anatomical characteristics of 25 supraspecific taxa in three genera are presented and compared in tables. The relationships and evolutionary position of these taxa are discussed. Each of the three subgroups within Iris appears to be correlated with a syndrome of anatomical characters. Some species currently of uncertain taxonomic position are discussed, and their classification based on anatomical data is suggested.
Some characters related to xeromorphy or helomorphy are mentioned.     

Comparative vegetative anatomy and systematics of Laeliinae (Orchidaceae)

Laeliinae are one of the most prominent orchid subtribes, with c. 40 genera and nearly 1500 species, and contain a disparate group of taxa with widely varying morphological features. There does not appear to be a complex of characters to which one can refer in order to delineate the subtribe as a whole. Thus, it was thought that vegetative anatomy might provide clues to the monophyly of the group. The microscopic structure of the leaves, stems and roots of representatives of most of the genera was studied. It was concluded that the anatomy lacks overall uniformity and that vegetative characters alone are insufficient to assess the relationships amongst the genera. The only nearly consistent anatomical feature was the abaxial row of fibre bundles in the leaves. Thus, anatomically, as well as morphologically, Laeliinae are a mixed bag. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 160 , 21–41.     

Systematic root anatomy of Asparagales and other monocotyledons

Root anatomy of several taxa of Asparagales and some taxa formerly included in Asparagales is described in a systematic context together with a literature review. The presence of a dimorphic outer layer with long and short cells is widespread in monocotyledons, indicating that it originated early in the monocot lineage, but whereas this layer is rhizodermal in most monocotyledons, in Asparagales and Araceae it is usually hypodermal. There may be a correlation between the presence of a velamen or a persistent rhizodermis in many Asparagales and Araceae and the presence of a dimorphic hypodermal layer. Many other root anatomical characters, such as the presence of vascular bundles in the central pith and a multi-layered sclerenchymatous cylinder, are probably xeromorphic and developed convergently.     

Leaf anatomy as an additional taxonomy tool for 18 taxa of Matricaria L. and Tripleurospermum Sch. Bip. (Anthemideae-Asteraceae) in Turkey

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.     

An integrative anatomical,morphological, micromorphological and molecular approach to Turkish epidendroid and orchidoid species (Orchidaceae)

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.     

MORPHOLOGICAL STUDIES OF THE NYMPHAEACEAE SENSU LATO. XVII. FLORAL ANATOMY OF ONDINEA PURPUREA SUBSPECIES PURPUREA (NYMPHAEACEAE)

Classification and phylogeny of the Nymphaeaceae are unresolved. This study provides floral anatomical data that will assist in elucidating generic interrelationships and systematic relationships to other taxa of angiosperms. The floral anatomy of Ondinea purpurea den Hartog subsp. purpurea has been examined utilizing light microscopy. The peduncle possesses stelar vascular bundle complexes and cortical vascular bundles. Cortical bundles terminate within the peduncle. Each bundle complex consists of 2 collateral bundles on the same radius, the inner bundle inverted; 2 protoxylary lacunae occur yet differ in structure and function. Progressing acropetally, the inner xylary lacunae become discrete mesarch strands surrounded centrifugally by a vascular cylinder formed by divisions and anastomosing of the bundle complexes. Together these become the massive receptacular vascular plexus. The plexus provides collateral traces to the floral organs. Each sepal receives 3 traces that separate from the plexus as 1–3 lateral traces. Petals are absent and no vestigial petal traces have been observed. Distally, the plexus forms several large strands of connate gynoecial and androecial traces termed the principal vascular bundles (PVBs). Ventral veins separate from the PVBs and the latter extend acropetally through the outer ovary wall. Branches of the ventrals and PVBs contribute to septal vascular reticula from which each ovule is supplied by one vascular bundle. Each stamen receives 1 trace from branches of the PVBs. The ventrals and PVBs terminate within the carpellary lobes. A comparative anatomical study is offered that supports the inclusion of Ondinea in the Nymphaeaceae sensu stricto.     

The root-tuber anatomy of Asphodelus aestivus

The root tubers of Asphodelus aestivus consist mostly of enlarged fleshy storage tissue. They are bounded by a multiple-layered velamen, responsible for rapid water uptake, water loss reduction, osmotic and mechanical protection. In the cortex area, thin-walled idioblasts contain numerous raphides of calcium oxalate in their large vacuole with a distinctive tonoplast. Wide morphological variations are observed among the raphide cross sections. Electron-dense compounds penetrate the raphide surface and raphide groove. Raphides seem to be vital for the protection of the root tuber parenchyma from herbivores. The cells of uniseriate endodermis are heavily thickened possessing a few plasmodesmata. The vascular cylinder is 20–28-arch and the root xylem consists of vessels in short radial rows, alternating with clusters of phloem cells. The presence of cells, which contain soluble polysaccharides in their large vacuole, is conspicuous after employing the Schiff's reagent. Exodermis cells and all cell walls, especially the thick ones of the endodermis, are also stained. Numerous parenchyma cells, especially those around vascular bundles are stained intensely, when exposed to Sudan Black B. These cells occurring as solitary idioblasts abundantly accumulate oil. Electron-dense remnants are evident within the vacuoles of the storage cells especially near the vascular tissue. The morphological features of A. aestivus root tubers and the major part of the total plant biomass are responsible for the species’ occurrence and frequent dominance in a wide array of arid environments. A. aestivus possessing root tubers is proved to be very efficient in storing water during the long summer drought, less susceptible to climatic stress and well synchronized with the climatic fluctuations of the Mediterranean environment.     

Leaf anatomy of the Menispermaceae tribe Tiliacoreae Miers

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.     

Leaf anatomy of the Pittosporaceae R. Br.

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.     

珍稀植物扇脉杓兰营养器官的解剖学研究

采用石蜡切片技术对扇脉杓兰营养器官的解剖结构进行了研究。结果表明：根状茎的薄壁细胞中含丰富的淀粉粒,维管柱中分布着排列紧凑的周木维管束;根的皮层发达,有的皮层细胞中存在真菌菌丝团,木质部与韧皮部呈辐射状相间排列,根和根状茎的内皮层细胞都形成马蹄形加厚结构。茎的表面分布气孔,皮层面积较小,皮层内部的基本组织发达,外韧维管束散生分布其中,茎和叶上都附有非腺性毛;叶为等面叶,叶肉细胞排列疏松,气孔主要分布于远轴面,略外凸,保卫细胞中含有叶绿体,叶缘处的叶肉组织中含有气腔结构。扇脉杓兰营养器官的这些特征与其荫蔽湿润的生境是相适应的。     

Anatomy of the Muhlenbergia Montana complex (Poaceae)

Leaf anatomical data from 13 taxa of the Muhlenbergia montana complex were surveyed, and 18 critical characters were found. Results obtained from the phenetic analysis of anatomical data have given independent data to compare with the morphological, phytogeographical, and flavonoid data (previously reported) in determining the relationships of the species. An anatomical dendogram illustrates a close corroboration. Leaf anatomy clearly supports the recognition of a close relationship among the two taxa — M. virescens and M. quadridentata—as has been suggested in previous reports. Therefore, a change of level is suggested in which M. quadridentata (H.B.K.) Kunth is proposed here as M. virescens (H.B.K.) Kunth ssp. quadridentata (H.B.K.) Herrera (comb. nov.).     

Morphology, anatomy and vasculature of leaves in Pinus (Pinaceae) and its evolutionary meaning

The morphology, anatomy and vasculature of Pinus leaves was studied. The results indicate that the Pinus leaf is always supplied with only one single vascular bundle, which is surrounded by a prominent bundle sheath. In several taxa, especially of subgenus Pinus, the vascular bundle may however be subdivided by longitudinal parenchymatic bands in the middle part of the leaf. As a result, the single bundle gets the appearance of two individual bundles, which are surrounded by a common bundle sheath. The general rule that a bundle sheath does sheath only one single bundle, as in other gymno- and angiospermous seed plants, applies therefore also for Pinus. The morphological and anatomical similarities between cladodes of Sciadopitys (Sciadopityaceae) and Pinus leaves are based on a completely different bauplan. The idea of “hidden cladodes” in some Pinaceae is therefore obsolete.     

Comparative floral anatomy of <Emphasis Type="Italic">Rhynchospora consanguinea</Emphasis> and <Emphasis Type="Italic">Rhynchospora pubera</Emphasis> (Cyperoideae,Cyperaceae)

Rhynchospora is one of the most species-rich genera of Cyperaceae and one of the few with entomophilous species. Considering the few anatomical studies of the genus, especially of the reproductive structures, this study comparatively analysed the anatomy of flowers of two representative species of Rhynchospora, R. consanguinea and R. pubera, including the floral vasculature and the anatomy of the style base, which is persistent with the fruit. Both species have congested inflorescences with light-coloured bracts and bisexual flowers, and phenolic idioblasts in the anthers and gynoecium, characteristics that suggest insect pollination. In R. consanguinea, the bisexual and the most proximal male flower has perianths, a new character state reported for the genus. The floral vasculature pattern is similar in both species, but differs from that previously described for Rhynchospora. In both species, there are two vascular bundles in the rachilla, which split into three receptacular bundles, the latter forming a vascular plexus where the bundles of stamens, gynoecium and ovule are connected. No lateral carpellary trace was observed, and the presence of the abaxial receptacular bundle was interpreted as a vestige of the tricarpellate ancestral condition. In the fruit of both species, the thickened style base (stylopodium) has a parenchyma with idioblasts containing phenolic compounds and idioblasts with helical or reticulate cell wall thickenings. The stylopodium is a homologous structure in the species of Rhynchospora and to other genera of Cyperoideae and evolved several times in the subfamily.     

The phylogenetic significance of the carpophore in Apiaceae

Background and aims

Fruit structural characters have traditionally been important in the taxonomy of the family Apiaceae. Previous investigations using a limited number of taxa have shown that the carpophore may be especially useful in helping to circumscribe subfamily Azorelloideae. The present study examines, for the first time, carpophore structure in 92 species from 43 genera, representing all subfamilies of Apiaceae, and including all genera assigned to subfamily Azorelloideae. Phylogenetic interpretations are made for the first time, using all available information, and a standard terminology is proposed to describe the various character states found in carpophores.

Methods

Carpophore structure was studied in detail using light microscopy.

Key Results

Carpophores, when present, may be categorized into two main groups (B and C) based mainly on the arrangement of the vascular bundles in transverse section, and further divided into six sub-types according to the length of the carpophore (short in B1 and C1) and whether they are entire (B1–B3 and C1) or bifurcate (B4 and C2). Free carpophores are absent in subfamily Mackinlayoideae, and in tribes Lichtensteinieae and Phlyctidocarpeae, which have two opposite vascular bundles (Group A). Entire carpophores with one or two vascular bundles, or bifurcate carpophores with lateral vascular bundles (arranged side by side within the commissural plane), are the main types characterizing Azorelloideae. The short, hygroscopic carpophores found in Choritaenia are unique in Apiaceae and provide additional evidence for the exclusion of this genus from Azorelloideae. Carpophore type C2 is typical for most Apioideae sensu lato (exceptions are, for example, Arctopus and Alepidea, which have type B2).

Conclusions

A single carpophore and ventral vascular bundles not forming free carpophores are proposed to be the ancestral conditions in Apiaceae, while bifurcate carpophores with opposite vascular bundles are the derived state, present in most Apioideae. Secondary reductions seem to have occurred in several unrelated lineages in all major groups, e.g. many Azorelloideae, several protoapioids (including nearly all members of the tribe Saniculeae) and 29 euapioid genera (e.g. some Oenantheae).     

A novel insight into the structure of amphivasal secondary bundles on the example of Dracaena draco L. stem

Key message

Pattern of tracheids found along the bundles extends understanding of their cross - sectional anatomy and sheds a new light on the issue of radial transport in monocotyledons with secondary growth.

Abstract

Secondary growth of Dracaena draco L. stem is connected with the formation of amphivasal vascular bundles in which a centrally located phloem is surrounded by a ring of xylem cells (tracheids). However, as visible in a single transverse section, there is a tendency towards variation among the secondary bundles from such with a xylem ring to ones in which the tracheids do not completely surround the phloem, i.e., are separated by vascular parenchyma cells. We aimed to elucidate the cross-sectional anatomy of amphivasal secondary bundles using the method of serial sectioning (with sections 3 μm thick), which allowed us to follow very precisely the bundle structure along its length. The analysis revealed that the xylem arrangement in these bundles depends on the position of a section in the bundle path. Each amphivasal bundle is composed of sectors where tracheids form a ring, as well as of such where tracheids are separated by vascular parenchyma cells. We hypothesize that this structure of amphivasal vascular bundles facilitates radial transport of assimilates to the sink tissues. The result of the anatomical analysis is discussed in a physiological context.