New evidence from the ultrastructural and micromorphological fields in angiosperm classification

Based on TEM investigations of some 1850 species and SEM examinations of about 6000 species of the Angiospermae, this is a survey of ultrastructural and micromorphological data (excluding pollen wall characters) which contribute valuable information for the classification of angiosperms. TEM characters predominately relate to phloem features, such as sieve–element plastids and crystalline P–protein, and to those equally present in other tissues, e.g. nuclear protein crystals and dilated ER–cisternae (DC). Of these, the sieve–element plastids with their types and subtypes (S, PI–PVI) and their over 20 forms represent the most thoroughly investigated TEM character. SEM characters mainly relate to epidermal surface features and can be grouped into four categories: (1) Cellular arrangement or cellular pattern; (2) Shape of cells (the “primary sculpture” of a surface); (3) Relief of outer cell walls (“the secondary sculpture” superimposed on the primary sculpture), caused mainly by cuticular striations and superficially visible wall inclusions and wall thickenings; (4) Epicuticular secretions (the “tertiary sculpture” superimposed on the secondary sculpture), i.e. mainly waxes and related substances. Ultrastructural evidence from sieve–element plastids for the classification of Mag–noliiflorae, Caryophylliflorae, Fabiflorae and the unity of the Monocotyledoneae is discussed, while further plastid data are listed for single families (e.g. Buxaceae, Cyrillaceae, Erythroxylaceae, Eucryphiaceae, Gunneraceae, Rhizophoraceae, Vitaceae). Crystalline P–protein dominates in Malviflorae, Violiflorae and Fabiflorae. Nuclear protein crystals are a specific feature of sieve elements of Boraginaceae. DC characterize Capparales s.lat. Micromorphological evidence derived from specific trichomes is presented as an aid to the characterization of Urticales and Loasales, while a detailed analysis of the micromorphology of the seed coat of Cactaceae and Orchidaceae provided new information for the classification of these families at the tribal and generic levels. As a completely new systematic feature for the classification of the Monocotyledoneae first results of micromorphological differences in wax crystalloids and their orientation patterns are presented: The Liliiflorae s. str. are clearly separated against the Zingiberiflorae–Commeliniflorae (incl. Velloziales, Bromeliales, Typhales) and Areciflorae, both characterized by two mutually exclusive and very specific wax types and delimited against taxa with unspecific waxes in the rest of the monocotyledons and all dicotyledons.     

中国水鳖科植物种皮微形态特征及其系统学意义

通过扫描电镜对国产水鳖科植物(包括6属13种)的种皮微形态特征进行观察,并作了系统描述。根据种皮细胞形态、外种皮表面纹饰和内种皮内层小瘤状突起的特点将水鳖科植物的种皮微形态特征划分为3种类型,即海菜花型(海菜花属)、水鳖型(水鳖属)和苦草型(苦草属、水筛属、虾子草属和黑藻属),并作出了分属检索表。本文结果表明,种皮微形态特征可作为该科族、属以及属内种级水平分类的依据,对探讨属间关系和该科的系统发育关系亦具有重要的价值。种皮微形态特征支持Hutchinson(1959)和Eckhardt(1964)将海菜花属和水鳖属分别作为一个独立的族处理的观点。苦草属、水筛属和虾子草属种皮微形态特征的高度相似性表明它们间有密切的联系,不支持将它们置于不同亚科和族的分类处理。黑藻属虽与上述3属近缘,但其外种皮特征则较为独特,因此与水筛属放在不同族中更为合理。本文种皮微形态特征的研究结果支持iki1937)和Shaffer-Fehre(1991b)等关于水鳖科与茨藻科近缘的观点。     

The micromorphologies of seed coats and petal trichomes of the taxa of Viola subsect. Boreali-Americanae (Violaceae) and their utility in discerning orthospecies from hybrids

Viola subsect.Boreali-Americanae, confined to North America including northern México, has long been considered one of the most taxonomically difficult temperate groups of the angiosperms. Hybridization, followed in some localities by introgression, has made it difficult for systematists to discern the “core” species by using only standard macromorphological characters. Analyses that employed scanning electron microscopy (SEM) of seed coats and petal trichomes generated new characters. SEM of the surface of seeds of each of the orthospecies revealed a suite of primary and secondary sculpture characters unique to each species that are correlated with a suite of macromorphological characters. In a number of species, SEM of petal trichomes provided additional unique characters. SEM of the surface of seed coats enabled, also, the identification of instances of hybridization by revealing blends of structures of the primary and secondary sculpture typical of different orthospecies and instances of putative introgression by revealing deviations in surface structures from those typical of orthospecies. A procedure based on iterative examinations of macromorphology and micromorphology, which was developed in this research, enable the discernment of hybrids and putative introgressants. Combining the micromorphological and macromorphological data with ecological and phytogeographical data enabled the delimitation of sixteen orthospecies.     

Studies of Pollen Morphology and Its Systematic Position in the Order Piperales

The pollen morphology of 25 species and 10 genera of Piperales (Chloranthaceae, Piperaceae and Saururaceae) has been examined under light microscope, of which 7 species were observed under scanning electron microscope and 1 species, Hedyosmum orentale Merr. & Chun transmision electron microseope. Three principal types of pollen were found: anasulcate (mostly) (sometime trichotomosulcate), inaperturate (partly) and multicolpoidate (partly). The present article has discussed the palynological data mainly in relation to the classification and the systematic position of Cbloranthaceae and also deals with the systematic position of the order Piperales. The present author agrees to put the family Chloranthaceae into the order Piperales. Because this family differs from Piperaceae and Saururaceae in pollen morphology, therefore, Chloranthaceae should raise to the level of suborder. Among three families of the order Piperales, the present author considers Chloranthaceae to be the most primitive family, on account of the following reasons: 1. The family Chloranthaceae shows the characteristics of primitive entomophilous plants in the sculpture of exine, while in the other two families, Piperaceae and Saururaceae, their exine is almost smooth and represents wind-pollenated plants; 2. Pollen of the family Chloranthaceae are larger than those of Piperaceae and Saururaceae; 3. The fossil pollen Clavatipollenites has been proved to be one of the most primitive angiosperms on the earth, that it is known, it occurred in the early Cretaceous, and at that time ferns and gymnosperms were predominant, while the Chloran- thaceae has already existed at that time; 4. Sarcandra of Chloranthaceae possesses the characters of a vesselless secondary xylem and a delayed development of embryo. Thus, Chloranthaceae would be considered as the most primitive family in the order Piperales. The systematic position of the order Piperales is also discussed. Itutehinson makes a point that order Ranales is more primitive than Piperales, and his system is arranged in the following order: Ranales → Piperales → to climax family Chloranthaceae. This view-point, however, is net supported by the palynological data. Pollen morphology shows that Piperales is more primitive than Ranales, because the pollen in Piperales possess the ancient aperture type of Pteridospermes, i.e., the type of anasulcate aperture is prevailing in Piperales, moreover, pollen grains of Ranales are mainly tricolpate type, and tricolpate pollen is a characteristic of typical angiosperms. In addition, the Piperales possesses a series of characters that are common among monocots, but rare among dicots. As the divergence between dicer and monocot took place in the early Cretaceous, their ancestor possesses common chararcters both of dicots and monocots while the extant Piperales still possess many characters of monocots that indicate it is much nearer to the point of divergence, and it explains that the Piperales is closely related to the ancestor of monocots and dicers Piperales, therefore, is more primitive than Ranales.     

中国茨藻科植物种皮微形态特征及其系统学意义

本文应用扫描电镜对国产茨藻科植物的外种皮和内种皮微形态特征进行了研究,结果表明茨藻科植物在种子表面细胞形态、表面纹饰和内种皮内层细胞形态及小瘤状突起的大小和密度等方面存在差异,可作为种级水平分类的依据,并首次发现外种皮微形态特征也与内种皮内层小瘤状突起一样具有重要的系统学意义。根据种皮微形态特征的研究结果,我们支持Miki(1937)和Shaffer-Fehre(1991b)等关于茨藻科与水鳖科近缘,而不应放在眼子菜目的观点。对弯果茨藻Najas ancistrocarpa A．Br．ex Magnus和草茨藻N.graminea Del.外种皮的研究结果表明其外种皮细胞表面具瘤状颗粒而非网状加厚。     

Studies on the Pollen Morphology and Seed Coat of the Genus Cistanche (Orobanchaceae) in China

In the present paper pollen grains of 5 species and seed coat of 4 species of the genus Cistanche (Orobanchaceae) from China were examined by scanning electron microscope As a result, two types of the pollen exine sculpture are distinguished: (1) tuberculate, C. salsa and C. lanzhouensis; (2) rugulate or fine reticulation formed by the fusion of rugae, C. sinensis, C. deserticola and C. tubulosa. Chinese Cistanche was classified into two sections based on the gross morphology by the present author (Zhang, 1984). C. lanzhouensis and C. sinensis were included in one section. This classification is in conflict with the pollen type, which indicates that the characters of pollen grains and external morphology in this genus have evolved at different rates. The differences in pollen morphology of Chinese Cistanche can serve as characters for delimitating species. According to our abservation, C. lanzhouenis Z. Y. Zhang differs from the other members of Cistanche not only in external morphology but also in pollen morphology. Pollen grains are subprolate in this species, while prolate in the other four species, and exine sculpture is tuberculate. The present study provides the establishment of this new species (Zhang, 1984) with palynological evidence. The seed coat sculpture in Chinese Cistanche are constantly alveolate, but there are some slight differences, by which the sculpture can be divided into two types: (1) testa cells have or have not thickenings on the inner anticlinal walls; cavernulous sculpture is present on outer periclinal wall of some cells: C. sinensis; (2) testa cells have striate thickenings on the inner anticlinal walls: C. salsa, C. deserticola and C. tubulosa. The characters of seed coatof some significance for the delimitation of species.     

Seed coat morphology and its systematic significance in Juncus L. (Juncaceae) in Egypt

The seed morphology of nine taxa of Juncus from Egypt has been investigated using light and scanning electron microscopy, to determine the importance of seed coat features as taxonomic characters. Macro- and micromorphological characters, including seed shape, color, size, seed appendages, epidermal cell shape, anticlinal boundaries, and outer periclinal cell wall and secondary cell wall sculpture are presented. Four types of seed appendages are recognized: (i) seeds with two appendages; (ii) seeds without appendages; (iii) seeds with minutely a piculate at one end; and (iv) seeds with minutely a piculate at both ends. Two types of anticlinal cell wall boundaries,(i) raised-channeled, straight and (ii) raised, straight or sinuous, and three different shapes of outer periclinal cell wall are described: (i) flat; (ii) concave; and (iii) flat to slightly concave. The secondary sculpture of the cell wall varies from striate to microreticulate or reticulate, and smooth to finely folded. Seed characters provide useful data for formulating the taxonomy of Juncus both on the subgeneric and sectional level. A key for the identification of the investigated taxa based on seed characters is provided.     

Seed coat morphology and its systematic significance in Juncus L. (Juncaceae)in Egypt

The seed morphology of nine taxa of Juncus from Egypt has been investigated using light and scanning electron microscopy,to determine the importance of seed coat features as taxonomic characters.Macro-and micromorphological characters,including seed shape,color,size,seed appendages,epidermal cell shape,anticlinal boundaries,and outer periclinal cell wall and secondary cell wall sculpture are presented.Four types of seed appendages are recognized:(i)seeds with two appendages;(ii)seeds without appendages;(iii)seeds with minutely a piculate at one end;and(iv)seeds with minutely a piculate at both ends.Two types of anticlinal cell wall boundaries,(i)raised-channeled,straight and(ii)raised,straight or sinuous,and three different shapes of outer periclinal cell wall are described:(i)flat;(ii)concave;and(iii)flat to slightly concave.The secondary sculpture of the cell wall varies from striate to microreticulate or reticulate,and smooth to finely folded.Seed characters provide useful data for formulating the taxonomy of Juncus both on the subgeneric and sectional level.A key for the identification of the investigated taxa based on seed characters is provided.     

Development and morphology of the gynoecium and nutlet in two South-American Bulbostylis (Cyperaceae) species

The anatomy and ontogeny of the gynoecium and nutlets of two Bulbostylis species with different micro-morphology, Bulbostylis capillaris sensu Barros and B. major, were analyzed. The specific aim of this work was to identify which part of the pericarp determines the differences in the nutlet surface between these two species. We found that pre-fertilization development is the same in both species, with differences between species appearing only after fertilization. In the nutlet of B. major, the exocarp forms a tuberculate primary sculpture that has nipple-like protuberances consisting of one conoidal silica body per cell, whereas the secondary sculpture is micro-granulose and is constituted by the cuticle. In the nutlet of B. capillaris, the primary sculpture is granulose and is formed by the presence of starch granules in the exocarp that do not degrade, whereas the secondary sculpture is smooth.     

中国东北牻牛儿苗科(Geraniaceae)种子形态特征及其分类学意义

本文对中国东北牛儿苗科(Geraniaceae)二属(太阳花属Erodium, 老鹳草属(Geranium)计14种(species)1变种(Variety)和1变型(form)植物的种皮亚显微结构(SEM)及种子形态进行了研究.结果表明, 太阳花属与老鹳草属植物无论从种子形状, 长宽比, 还是种皮初级雕纹及次级雕纹形态都表现出明显差异。在老鹤草属下种及种下等级的鉴定和划分上, 种皮微形态及种子形态特征提供了大量有价值的信息。     

Testa sculpture in the genus Frailea (Cactaceae)

The primary sculpture of the seed surface in the genus Frailea (Cactaceae) is characterized by a i flat outer periclinal wall and the presence of an usually eccentric papilla. Papilla morphology differs mainly in size and breadth:length ratio. Seeds of different species (groups) are characterized by special patterns in the arrangement of short and long papillae on the surface, thus providing a useful tool for taxonomic studies in Frailea. The seeds of Frailea castanea possess branched papillae, a character restricted in this genus to this species. Moreover, such papilla morphology seems to be unique for the seed epidermis in spermatophytes. The possible function of the papillae is discussed.     

中国水鳖科( Hydrocharitaceae )植物的果皮微形态特征

应用扫描电镜对国产水鳖科６属植物的果皮微形态特征进行了初步的观察。结果表明水鳖科各属植物在果皮表面纹饰及表皮细胞形态,径向壁和横向壁凸出与否等特征上存在差异,可以作为属间分类的依据之一。从果皮微形态特征来看,水鳖属和海菜花属差异很大,支持将它们分别作为不同的族处理的观点,而水筛属和苦草属则较为近缘。果皮微形态下的观察结果表明水鳖科和泽泻科植物在果皮表面细胞形态,径向壁明显凸出等方面十分相似,因而支持了水鳖科与泽泻目近缘的观点。     

14种石斛属(兰科)植物的花粉团形态及分类学意义

利用体式显微镜和扫描电镜观察了14种石斛的花粉团形态及其表面纹饰超微特征,为该属的物种划分和系统演化提供花粉形态证据。解剖镜下,14种石斛的花药里有4枚花粉团,表面金黄油亮呈蜡质,质地坚硬。根据每种石斛的4枚花粉团的总体轮廓形态和大小,可分为3种形态(心形、近心形和长心形)和4种类型(极小花粉团,小花粉团,大花粉团和超大花粉团)。根据单个花粉团边界轮廓的曲直,可将其分为4种类型(月牙型、弓型、棍状和米粒型)。扫描电镜下,14种石斛的花粉团表面纹饰类型有5种(光滑平整型、光滑带丝状突起型、光滑不平整型、粗网纹状型和皱波状型),在广东石斛和球花石斛的花粉团表面观察到晶体的存在。花粉团的形态大小和外壁纹饰特征在种间变化明显,对澄清石斛属的分类学问题有一定意义。     

中国水鳖科（Hydrocharitaceae）植物的果皮微形态特征

应用扫描电镜对国产水鳖科6属植物的果皮微形态特征进行了初步的观察。结果表明水鳖科各属植物在果皮表面纹饰及表皮细胞形态,径向壁和横向壁凸出与否等特征上存在差异,可以作为属间分类的依据之一。从果皮微形态特征来看,水鳖属和海菜花属差异很大,支持将它们分别作为不同的族处理的观点,而水筛属和苦草属则较为近缘。果皮微形态下的观察结果表明水鳖科和泽泻科植物在果皮表面细胞形态,径向壁明显凸出等方面十分相似,因而支持了水鳖科与泽泻目近缘的观点。     

An unusual megaspore of uncertain systematic affinity from Lower Cretaceous deposits in south-east England and its biostratigraphic and palaeoenvironmental significance

An unusual megaspore has been recorded from beds within the Weald Clay Group of south-east England. Described as Clockhousea capelensis gen. et sp. nov., it is characterised by having a thick outer layer of exine consisting of closely packed columnar to clavate elements with constricted bases attached to a perforated inner layer and a sculpture that ranges from having the appearance of a negative reticulum through closely spaced verrucae to a mixture of verrucate and essentially baculate elements, all of which are surface manifestations and extensions of the underlying structure. These characters do not readily indicate a systematic relationship with any known heterosporous plant genus or family. The localised occurrence and relative abundance of the spores in a few beds suggest that some of the parent plants grew close to water bodies where they were deposited and preserved. Their recovery from sediments of late Hauterivian–early Barremian age indicates that the species has potential as a biostratigraphic marker in the upper Wealden succession of southern England and perhaps elsewhere.     

Comparative Observation on Leaf Anatomy and Pollen of Vernicia Lour. and Aleurites J. R. et G. Forst.

The folial anatomy and pollen of one species of Aleurites and two species of Vernicia were studied. The former genus is characterized by the presence of echinolophate sculpture of pollen and a single outer stomatal ledge, curved cuticular ridges of peristomatal rim as well as large nodular ornamentation on the surface of epidermis beneath which there is no hypodermis. The latter one is characterized by the verruca-murate sculpture of pollen and the cuticular striate ornamentation on leaf surface of epidermis beneath which there is one layer of hypodermis, although they both have paracytic stomata and the Crotonic type of pollen. The genus Vernicia has not been accepted for a long time, but these micromorphological characters show as additional evidence that recent separation of the two genera by Airy Shaw (1966)^[6] is reasonable. Both genera possess very similar xeromorphic feature designated here as orbicular lustrous spot.     

Scanning electron microscopy of pollen grains of some species of the genusArum (Araceae)

A preliminary report is given on the pollen morphology of eight species of the genusArum examined by scanning electron microscopy. The pollen grains are spheroidal and their sporoderm sculpture possesses spines. The species vary mainly in number, shape and distribution of the spines on the pollen surface and these characters can be used to differentiate them.     

Vergleichende Mikromorphologie der Narbenoberflächen bei den Angiospermen; Zusammenhänge mit Pollenoberflächen bei heterostylen Sippen

Stigmatic surfaces of about 250 species from more than 100 families were examined by scanning electron microscopy. There are five main groups which differ by the amount of secretion, the morphology of the surface and the distribution of receptive cells. The types of stigmatic surfaces are often remarkably constant on the family level.Ericaceae andLiliaceae are examples for very heterogenous families. Particular interest was paid to heteromorphic (heterostylous and cleistogamous) species. In most heterostylous species there is a close morphological correlation between the stigmatic surface and the sculpture of compatible pollen. Heterostyly was established for the genusGoniolimon. The dimorphism of plants with chasmogamous and cleistogamous flowers is a phenomenon which is not comparable to the polymorphism of heterostylous forms.

     

On the phylogeny of the Arminidae (Gastropoda, Opisthobranchia, Nudibranchia) with considerations of biogeography

In the past, the different genera of the family Arminidae have been diagnosed (mostly) on the basis of plesiomorphic characters and therefore their monophyly is questionable. The Arminidae are characterized by the autapomorphies 'possession of marginal sacs' and 'rhinophores with longitudinal lamellae'. The genus Heterodoris is excluded from the family. Two possible hypotheses about the phylogenetic relationships within the Arminidae are presented.
The Arminidae probably originated in the western Pacific, near Japan and have distributed in a westerly direction. The most primitive species ( Dermatobranchus ) are restricted mainly to the western Pacific region while the more derived species ( Armina ) have a world-wide distribution.