Leaf and twig anatomy of Eriope, a xeromorphic genus of Labiatae

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.     

Leaf anatomy of Bruniaceae: ecological, systematic and phylogenetic aspects

CARLQUIST, S., 1991. Leaf anatomy of Bruniaceae: ecological, systematic and phylogenetic aspects. Quantitative and qualitative data are given for 60 species of the 12 genera of Bruniaceae; most data are based on liquid-preserved material. Leaves of Bruniaceae are basically linear (broader forms are probably derived) with an apicula that contains phellogen activity. Most bruniaceous leaves have some degree of isolateral construction, with transition to normal bifacial construction in a few species, but more commonly transition to 'inverse' bifacial structure (stomata on adaxial face, palisade on abaxial face). The latter type is correlated with the tendency for leaves to be appressed to stems. Tannins and very likely other dark-staining materials are very characteristic of mesophyll cells. Six genera have a large strand of fibres on the midvein and rhomboidal crystals in bundle sheath cells. The other six genera have few or no fibres on veins and have druses in mesophyll cells (but not in bundle sheath cells). These distinctions may relate to intrafamilial taxonomy, but they also support the primitive position usually accorded to Audouinia, Thamnea and Tittmannia. A key to genera based on leaf antomy is offered. Details of epidermal cell shape, cuticular relief and trichome form and structure based on scanning electron microscopy are given. Leaf anatomy, combined with other features, favours a relationship between Bruniaceae and Grubbiaceae in particular and in broader contexts allies Bruniaceae to rosalean and possibly hamamelidalean families.     

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.     

Stem anatomy of the dwarf subshrub Cressa cretica L. (Convolvulaceae)

Stem anatomy and development of medullary phloem are studied in the dwarf subshrub Cressa cretica L. (Convolvulaceae). The family Convolvulaceae is dominated by vines or woody climbers, which are characterized by the presence of successive cambia, medullary- and included phloem, internal cambium and presence of fibriform vessels. The main stems of the not winding C. cretica shows presence of medullary (internal) phloem, internal cambium and fibriform vessels, whereas successive cambia and included phloem are lacking. However, presence of fibriform vessels is an unique feature which so far has been reported only in climbing members of the family. Medullary phloem develops from peri-medullary cells after the initiation of secondary growth and completely occupies the pith region in fully grown mature plants. In young stems, the cortex is wide and formed of radial files of tightly packed small and large cells without intercellular air spaces. In thick stems, cortical cells become compressed due to the pressure developed by the radial expansion of secondary xylem, a feature actually common to halophytes. The stem diameter increases by the activity of a single ring of vascular cambium. The secondary xylem is composed of vessels (both wide and fibriform), fibres, axial parenchyma cells and uni-seriate rays. The secondary phloem consists of sieve elements, companion cells, axial and ray parenchyma cells. In consequence, Cressa shares anatomical characteristics of both climbing and non-climbing members. The structure of the secondary xylem is correlated with the habit and comparable with that of other climbing members of Convolvulaceae.     

东北桤木叶表皮盾状腺毛的形态及其变化过程

利用电镜扫描技术,观察东北桤木叶片表面,发现其远轴面表皮上具有盾状腺毛。其由2个基细胞、4个柄细胞和20～25个头部细胞组成,随着分泌物质的积累,细胞逐渐破裂。幼叶远轴面表皮无盾状腺毛,仅有气孔分布。观察东北桤木叶片横切面,发现其为异面叶,远轴面表皮上的盾状腺毛细胞与叶脉维管组织相连。外文资料显示用于表述桤木属表皮上的盾状腺毛的名词较多,该毛状体应为“Peltate glandular hairs”。同时建议对“Glandular scales”、“Peltate gland”、“Peltate scale”、“Peltate glandular hairs”等名词进行规范统一。另外有关东北桤木叶表皮上毛状体从原表皮细胞的发生过程及其分泌物的成份,需进一步研究。     

Leaf epidermal features of Lithocarpus (Fagaceae) from China and their systematic significance

The leaves of 52 species of Lithocarpus in China were studied. The adaxial leaf epidermis was investigated by light microscopy. Epidermal cells of the adaxial surface were classified into three types on the basis of the outline of their anticlinal walls, i.e. sinuate, straight and curved. The abaxial leaf epidermis was investigated by light microscopy and scanning electron microscopy. The following types of trichome were observed: appressed parallel tuft, stellate, fused stellate, papillae, stipitate fasciculate, solitary unicellular, appressed laterally attached unicellular, curly thin‐walled unicellular, bulbous and thin‐walled peltate. The fused stellate, appressed laterally attached unicellular and curly thin‐walled unicellular trichomes were reported in Lithocarpus for the first time. The appressed parallel tuft trichome, which is recognized as a salient characteristic of Lithocarpus, was not found in 15 species. A cladistic analysis was performed on the basis of the leaf epidermal features. According to the leaf epidermal features and several morphological characteristics, 26 of the 52 species could be divided into seven groups. Similar groups can be found in Barnett's and Camus' systems. The trichomes of four genera in Fagaceae are listed and compared. Lithocarpus had 14 types of trichome, 11 of which were identical to types found in Quercus, more than in Castanopsis and Cyclobalanopsis. The evolutionary trends of trichomes in Fagaceae are discussed and a new point of view is raised. © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 168 , 216–228.     

Leaf anatomy of Gluta (L.) Ding Hou (Anacardiaceae)

An anatomical study of the leaves of 21 species of Gluta (L.) Ding Hou (Anacardiaceae) reveals two major groups of species which reflect the original groups of Gluta L. and Melanorrhoea Wall., and a smaller group showing intermediate, or an admixture of, characters. The anatomical characters found to be of most use in this respect are: stomatal outline in surface view; stomatal density; glandular trichomes present/absent; glandular trichome body raised/sunken; cuticle striate/not striate; midrib dimensions as seen in transverse section; kind of simple trichomes (trichome-types 1–4); epidermal cell anticlinal wall undulation and whether visible or not on cuticular surface; resin ducts present/absent in medullary parenchyma of midrib. These characters have been used in a key to the species. Some evidence is given that the lacquer covering the leaf surface of some species is produced by the terminal cells of the glandular trichomes.     

中国杜鹃花属的叶表皮特征及其系统学意义

通过光学显微镜和扫描电镜对国产杜鹃花属Rhododendron6个亚属48种4变种植物的叶表皮特征进行观察,结果表明叶表皮的鳞片、腺体、表皮毛的有无和气孔器的类型具有一定的系统学意义。光学显微镜下可见：叶表皮细胞形状为多边形、不规则形,垂周壁式样为较平直、浅波状和波状．气孔器普遍存在于下表皮,上表皮未见气孔器分布,其类型均为无规则形。杜鹃亚属subgen．Rhododendron叶表皮具有鳞片,在扫描电镜下可见气孔器散生于指状突起之间,有别于无鳞类杜鹃花。常绿杜鹃亚属subgen．Hymenanthes和映山红亚属subgen．Tsutsusi有多种不同叶表皮类型;除了凯里杜鹃R．westlandii和弯蒴杜鹃R．henryi形态较特殊之外,马银花亚属subgen．Azaleastrum的马银花组sect．Azaleastrum和长蕊杜鹃组sect．Choniastrum微形态区别不明显。羊踯躅亚属subgen．Pentanthera的羊踯躅R．molle叶表皮有表皮毛,无腺体,气孔器密生,外拱盖形状不对称,外围有多层波形条纹突起可与其他亚属区分：而叶状苞亚属subgen．Therorhodion的叶状苞杜鹃R．redowskianum保卫细胞有明显的T型加厚,与其他亚属种类明显不同,与分子系统发育研究得到的“叶状苞亚属是杜鹃花属的基部类群”的结果吻合。本研究还依据叶表皮微形态特征讨论了一些近缘种类的关系。     

Leaf epidermal features of Rhododendron (Ericaceae)from China and their systematic significance

Rhododendron is the largest genus within the subfamily Rhododendroideae, which has about 1000 known species in the world and more than 500 species in China. Since the genus was established by Linnaeus, its infrageneric relationships have been well studied by many taxonomists on the basis of morphological characters and molecular data. In 1996, Chamberlain et al. proposed a new system of Rhododendron with eight subgenera, i.e., Azaleastrum, Candidastrum, Hymenanthes, Mumeazalea, Pentanthera, Rhododendron, Therorhodion, and Tsutsusi. In this paper, micromorphological characters of leaf epidermis in 4 varieties, 48 species, 6 subgenera of Rhododendron from China were examined using light microscopy (LM) and scanning electron microscopy (SEM). Leaf epidermal features are described and micromorphological types are distinguished here according to morphological characters such as scale, gland, foliar trichome and stomatal apparatus of leaf epidermis. It is shown that the leaf epidermal cells are usually irregular or polygonal in shape. The patterns of anticlinal walls are straight, arched or undulate. The stomatal apparatuses are anomocytic and are usually found on abaxial, not adaxial, epidermis. The results also show that: (1) the lepidote rhododendron (i.e., subgen. Rhododendron), which has both scales and papillae on leaf epidermis, differs distinctly from the elepidote rhododendron; (2) three types of leaf epidermis are identified in subgen. Hymenanthes (i.e., R. fortunei-type, R. chihsinianum-type and R. simiarum-type), whereas four in subgen. Tsutsusi (i.e., R. mariesii-type, R. simsii-type, R. mariae-type and R. flosculum-type); (3) except for R. westlandii and R. henryi, the species of subgen. Azaleastrum show similar morphological characters, i.e., dense stomatal apparatuses surrounded by ringed or discontinuous striates; (4) R. molle of subgen. Pentanthera differs from the species of other subgenera on morphological characters such as foliar trichomes, dense stomatal apparatuses with asymmetrical outer stomatal rims surrounded by undulate-striates, and no gland; (5) only R. redowskianum is found with distinct T-pieces at the polar region of guard cells in Rhododendron. The results support the conclusion inferred from molecular systematic studies that subgen. Therorhodion is the basal clade of Rhododendron. Finally, the relationships between the closely related species are also discussed on the basis of leaf epidermal features.     

Leaf anatomy of the subtribe Hyptidinae (Labiatae)

The leaf anatomy of the subtribe Hyptidinae (Labiatae), which consists of four small genera and the largr genus Hyplis , is dercribed. The leaves may be dorsiventral or isobilateral. Variable characters of the lainina include: frequency and forms of trichomes, cuticular markings, presence of adaxial stoinata, thickness of leaf, thickness of adaxial epidermis, presence of a hypodermis, occurrence of sclcrified tissues (especially sclerified bundle sheath extensions, phloem and xylem fibres), mesophyll structure and venation pattern. Petiole vasculature varies from simple to complex, sometimes with medullary traces present. Most of the variable characters are related to xeromorphy and are tax-onomically useful within the framework of the present classification.     

Shoot anatomy and secretory structures in Hypericum species (Hypericaceae)

The anatomy and ultrastructure of internodes, leaves and petals were compared in Hypericum elegans, H. inodorum, H. olympicum, H. forrestii and two genotypes of H. perforatum. Internode anatomy was variable between species with respect to the structure of the cortical and pith parenchyma, including the presence of secretory reservoirs. Also, the secondary growth was more extensive in shrubs, i.e. H. inodorum and H. forrestii. In leaves, phloem secretory reservoirs were formed in all species, mesophyll secretory reservoirs were absent only in H. elegans and internal nodules were present only in H. elegans and H. perforatum. The petals differed between species in the mesophyll structure and the occurrence and location of secretory structures. The phloem secretory reservoirs lacked sheaths, whereas these were distinct in the mesophyll reservoirs. Other ultrastructural traits of the reservoirs were similar in all the species studied, with the exception of the leucoplast ultrastructure. In internal nodules, the inner cells vs. sheath cells differed in the number of vesicles and other membranous structures and plastid ultrastructure. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 163 , 70–86.     

Leaf anatomy inCaesalpinia andHoffmannseggia (Leguminosae,Caesalpinioideae) with emphasis on secretory structures

Leaflets of 65 species ofCaesalpinia s.l. and seven species ofHoffmannseggia were studied in clearings supplemented by resin sections and scanning electron microscopy. Three types of secretory structure occurred among 46 species; in 43 species they were distributed mutually exclusively (external glands: 8 species; internal cavities: 5 species; idioblastic cells: 30 species); three other species each had two types. Species with secretory structures conform mostly to proposed subgenera and informal groups. Other unusual features were external glands with internal spaces, thickened walls or conspicuous localized wall thickenings in epidermal cells or mesophyll cells of certain species, and differentially stained epidermal cells surrounding stomata. Prismatic crystals predominate but druse crystals also occur.     

Leaf morphology and anatomy of Camellia section Camellia (Theaceae)

The delimitations of species in Camellia section Camellia have been disputed for many years, resulting from uncertain relationships among species. Leaf morphological and anatomical characters for 54 species and three varieties in this section were investigated to reveal the relationships. Principal component analysis and cluster analysis were conducted using the transformed data for quantitative and qualitative characters from leaf morphology and anatomy. Combining the results of statistical analysis with comparative leaf characters of morphology and anatomy, we discussed the taxonomic treatment of section Camellia by Chang compared with that of Ming and we conclude that section Camellia consists of c. 50 species. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 456–476.     

Parapodial glandular organs in Spiophanes (Polychaeta: Spionidae)—studies on their functional anatomy and ultrastructure

Parapodial glandular organs (PGOs) of Spiophanes (Polychaeta: Spionidae) were studied using light and electron microscopy. These organs are found in parapodia of the mid body region, starting on chaetiger 5 and terminating with the appearance of neuropodial hooks (chaetiger 14 or 15 in adult individuals). Large PGOs in anterior chaetigers display different species‐specific types of openings whereas small PGOs in posterior parapodia of the mid body region always open in a simple vertical slit. Each PGO is composed of three main complexes: (1) the glandular sac with several distinct epithelia of secretory cells and secretory cell complexes and the reservoir filled with fibrous material, (2) the gland‐associated chaetal complex (including the region of chaetoblasts and follicle cells, follicular canals, two chaetal collector canals, the combined conducting canal, the chaetal spreader including the opening of the glandular organ with associated type‐1 secretory cells, and the gland‐associated chaetae), and (3) a bilayered musculature surrounding the gland. A considerable number of different cell types are involved in the secretory activity, in the guidance of the gland‐associated chaetae, and in the final expulsion of the fibrous secretion at the opening slit. Among these different cell types the type‐5 secretory cells of the proximal glandular complex with their cup‐shaped microvilli emanating thick microfibrils into the lumen of the glandular sac are most conspicuous. Secretory cells with cup‐shaped microvilli being involved in the production of β‐chitin microfibrils have so far only been reported from some representatives of the deep‐sea inhabiting Siboglinidae (Polychaeta). We suggest that the gland‐associated chaetae emerging from inside the PGOs of Spiophanes are typical annelid chaetae formed by chaetoblasts and follicle cells. Functional morphology implies the crucial role of PGOs in tube construction. Furthermore, the PGOs are discussed in consideration of phylogenetic aspects. J. Morphol., 2012. © 2011 Wiley Periodicals, Inc.     

Leaf teeth, transpiration and the retrieval of apoplastic solutes in balsam poplar

The rapid flow of the transpiration stream through major veins to leaf teeth was followed in leaves of Populus balsamifera L., using the tracer sulphorhodamine G (SR), which probes for cells with H⁺-extrusion pumps. The tracer accumulated quickly in the hydathodes of the teeth. It was shown by freeze-substitution and anhydrous processing that SR was taken up by phloem parenchyma and epithem cells of the hydathode. When ¹⁴C-labelled aspartate was fed to the leaves in the transpiration stream, it also was taken up most strongly by the same phloem parenchyma and epithem cells. It is proposed that one function of the hydathodes in leaf teeth is the retrieval of solutes from the transpiration stream.     

Leaf development of the ostrich fern Matteuccia struthiopteris (L.) Todaro

The timing of emergence of the three different leaf types of Matteuccia struthiopteris is described from plants sampled over the course of a growing season. Vegetative leaves were first to appear, followed five weeks later by sporophylls and cataphylls. Leaf number and type, and total leaf dry weight per plant were assessed in weekly transects. Vegetative fronds contributed the most to total leaf dry weight, which increased during the first four weeks, and then remained constant for the remainder of the season. Cataphylls, although numerous by the end of the season, contributed little weight. Sporophylls occurred on the widest plants with the most vegetative leaves and greatest leaf weight, whereas cataphylls occurred on most plants except the smallest. Experimentally defoliated plants were re-examined in late summer. Following initial harvest, plants often produced a second smaller set of leaves. These were restricted to vegetative leaves and cataphylls. Ability to reissue leaves, especially vegetative fronds, declined very quickly after the first few weeks in the growing season. Defoliated plants draw on the extensive reservoir of developing leaves which are found on the rhizome, thus possibly diminishing the ability of the plant to withstand regular harvesting of the young fronds for food. Individual leaves were tagged and measured over the growing season. Non-linear regression curves fitted to the growth data for the three types of leaves indicate that growth was described best by a monomolecular growth curve for the vegetative and fertile fronds. Cataphyllar growth could be described equally well by either a monomolecular or a logistic function.     

Developmental anatomy of the three-dimensional leaf ofBotrychium ternatum (Thunb.) Sw.

The ophioglossaceous leaf exhibits a unique morphology, three-dimensional constitution. This examination clarified the developmental manner of the leaf ofBotrychium ternatum (Thunb.) Sw. The leaf primordium develops as an ordinary appendicular leaf which shows a typical hyponastic growth curvature, though it soon takes a conical shape with a tetrahedral apical cell. The leaf primordium forms a sporophyll primordium first, then forms vegetative primary pinnae acting as the trophophyll primordium. The sporophyll primordium also forms sporogenous primary pinnae. The sporophyll initiation begins with establishment of a new apical cell (sporophyll apical cell) near the original leaf apical cell. Through activity of the sporophyll apical cell most of the sporophyll primordium is formed later. In contrast, the vegetative or sporogenous primary pinna begins to develop as a low mound of surface cells on the trophophyll or sporophyll primordium respectively. The apical cell is later established on the summit of each pinna primordium. In the developmental point of view, the sporophyll primordium is not equivalent to the primary pinnae on the trophophyll primordium. The sporophyll may not represent two fused basal pinnae of a leaf, but represents an organ independent of and equivalent to the trophophyll.     

Leaf development of the ostrich fern Matteuccia struthiopteris (L.) Todaro

The timing of emergence of the three different leaf types of Matteuccia struthiopteris is described from plants sampled over the course of a growing season. Vegetative leaves were first to appear, followed five weeks later by sporophylls and cataphylls. Leaf number and type, and total leaf dry weight per plant were assessed in weekly transects. Vegetative fronds contributed the most to total leaf dry weight, which increased during the first four weeks, and then remained constant for the remainder of the season. Cataphylls, although numerous by the end of the season, contributed little weight. Sporophylls occurred on the widest plants with the most vegetative leaves and greatest leaf weight, whereas cataphylls occurred on most plants except the smallest. Experimentally defoliated plants were re-examined in late summer. Following initial harvest, plants often produced a second smaller set of leaves. These were restricted to vegetative leaves and cataphylls. Ability to reissue leaves, especially vegetative fronds, declined very quickly after the first few weeks in the growing season. Defoliated plants draw on the extensive reservoir of developing leaves which are found on the rhizome, thus possibly diminishing the ability of the plant to withstand regular harvesting of the young fronds for food. Individual leaves were tagged and measured over the growing season. Non-linear regression curves fitted to the growth data for the three types of leaves indicate that growth was described best by a monomolecular growth curve for the vegetative and fertile fronds. Cataphyllar growth could be described equally well by either a monomolecular or a logistic function.