The significance of the leaf epidermis in the taxonomy of the Combretaceae

The epidermal anatomy, with special reference to the glandular trichomes, is surveyed in the Asian species of the genus Combretum. Emphasis is laid on the value of such characters in reviewing the sectional classification of the genus. It is concluded that sections Quadrangulares, Squamosae, Tetragonocarpus and Flagrocarpeae should be amalgamated to form an enlarged section Tetragonocarpus. It is also likely that sections Quisqualoides, Ovalifoliae and Dasystachyeae , and sections Decandra'e and Kaloëdron , should be amalgamated.     

The significance of the leaf epidermis in the taxonomy of the Combretaceae: conclusions

The classification of the Combretaceae in relation to the anatomy of the leaf epidermis (especially to trichomes) is surveyed, with particular reference to Combretum . The new combination Calopyxis grandidieri (Drake) Capuron ex Stace is made and the new section Calopyxis sect. Petalantha Stace is described. A sectional review of Combretum is presented. The 69 sections are reduced to 45, and full bibliographic details, typification and synonymy are set out.     

The significance of the leaf epidermis in the taxonomy of the Combretaceae. V: The genus Cimbretum subgenus Cacoucia in Africa

The anatomy of the leaf epidermis of 49 of the approximately 65 African species of Combretum subgenus Cacoucia is described. This is discussed in relation to the taxonomy of the subgenus, particularly its sectional classification. Of the 17 sections which have been describrd, Campylogyne is now referred to the genus Quisqualis, Argyrotricha is referred to Combretum subgenus Combretum , and Angolensia, Grandiflora, Mweroensia, Parvula and Trichopetala are included with other sections. Combretum grandidieri is referred to the genus Calopyxis . In general the leaf epidermis of speries of subgenus Cacoucia is of far lower taxonomic value than in subgenus Combretum .     

The significance of the leaf epidermis in the taxonomy of the combretaceae III. The genus combretum in America

The value of the leaf epidermis, particularly the glandular trichomes, in the identification and classification of the 37 species of Combretum recognized in America is assessed. The wide range of trichome types found, in general, differentiates groups of species corresponding closely with the 11 sections recognized by Exell, rather than distinguishing individual species. The taxonomic value of these trichomes is demonstrated to be at least as great as that of any other organ in the genus, and in a number of cases valuable criteria have been obtained for the first time.     

百部科植物叶表皮特征及其分类学意义

利用光学显微镜和扫描电子显微镜,对百部科4属30种植物的叶表皮微形态特征进行了观察研究。结果显示,叶表皮细胞形状仅有无规则形和多边形2种,垂周壁式样有深波状、浅波状和平直-弓形3种;表皮角质层纹饰微形态多样化,绝大多数物种的叶片表面不具有毛被,仅少数植物叶片表面具单细胞毛;气孔器主要分布在下表皮,仅Stemona prostrata I.R.H.Telford、S.cochinchinensis Gagnep、S.rupestris Inthachub、S.pierrei Gagnep和S.involuta Inthachub 5个种上下表皮均有气孔器;气孔形状均为椭圆形,而气孔器类型均为无规则型。百部科叶表皮微形态特征在属间有一定差异,但在属内各种间没有明确规律,表明该类群应该是一个自然的单系类群。由于百部科植物采样困难,在缺乏系统进化树数据的情况下,这些微形态特征可为探讨百部科不同种类的分类学、生物地理及其生态适应性提供部分新证据。     

葡萄科植物叶表皮特征及其系统学意义

在光学显微镜和扫描电镜下,对葡萄科Vitaceae11属37种代表植物的叶表皮特征进行了观察,发现该科植物叶表皮细胞形状为无规则形或多边形,垂周壁一般为平直、弓形或浅波状;气孔器通常仅分布在下表皮（火筒树属Leea偶尔可在上表皮观察到）,除无规则型（地锦属Parthenocissus、俞藤属Yua、葡萄属Vitis、蛇葡萄属Ampelopsis和酸蔹藤属Ampelocissus）最为常见外,不等细胞型（火筒树属）、短平列型（白粉藤属Cissus、乌蔹莓属Cayratia和崖爬藤属Tetrastigma）、     

Morphological characters of leaf epidermis in schisandraceae and their systematic significance

The leaf epidermis of 23 species belonging to 2 genera within Schisandraceae was investigated using light and scanning electron microscopy. Many characters of the leaf epidermis in Schisandraceae, such as shape of epidermal cells, type of stomata, and cuticular ornamentation, are usually constant within species and thus helpful for elucidating the relationship between and within genera. Leaf epidermal cells are usually irregular or polygonal in shape. The patterns of anticlinal walls are straight, sinuolate, sinuous or sinuate. The stomatal apparatus belong to paracytic or laterocytic type and the latter is subdivided into various subtypes based on the number and arrangement of subsidiary cells. Under scanning electron microscopy observation, the cuticular membrane is often striated, sometimes squamulate or granular; the inner margin of the outer stomatal rim is nearly smooth or denticulate. Evidences from shape of epidermal cells, patterns of cuticular intrusions between the ends of each guard cell of a pair and distribution of stomatal apparatuses support the viewpoint thatKadsura is more primitive thanSchisandra. Study on leaf epidermis also shows thatKadsura interior deserves the rank of a distinct species and the treatment of the evergreen groups, includingS. propinqua andS. plena, as distinct from the deciduous species of the genus is quite natural.     

Structural characters of leaf epidermis and their systematic significance in Vitaceae

Leaf epidermis of 37species representing 11 genera of Vitaceae was investigated using light microscopy（LM）and scanning electron microscopy（SEM）.The shapes of leaf epidermal cells are usually irregular or polygonal;the patterns of anticlinal walls are stra     

獐牙菜属植物叶表皮特征

利用光学显微镜观察了獐牙菜属３５种植物的呈表皮,发现该属植物成熟叶上下表皮细胞形状（表面观）为多边形和不规则型,垂周壁式样为平直、弓形和波纹,多数种类上、下表皮均有气孔器分布,气顺类型主要有３种,无规则型,不等型和平列型。这些特殊２对獐牙菜属下分类有一定的意义。结合其它方面的研究成果,初步确定叶表皮特征可能具有以下演化趋势,垂周壁式样深波方←浅波纹→平直,弓型,气顺类型无规则型→不等型→平列型。     

Evaluation of seed and leaf epidermis characters in the taxonomy of some annual species of the genus Papaver (Papaveraceae)

To get a better understanding of their taxonomic importance, we examined morphological, leaf epidermal and seed micromorphological characters of 19 taxa of annual Papaver L. belonging to the sections Papaver, Carinatae Fedde and Rhoeadium Spach. Among the studied taxa, the pattern of the coat of the seed testa cells and seed epidermal cell showed large variation. The granulate type of testa sculpturing was most common, but other types were represented by one or two species. In contrast, most of the taxa have broadly similar leaf epidermal characteristics. We conclude that variation in seed characters are significant for the taxonomy at the specific and generic levels, whereas leaf epidermis morphology, with few exceptions, is mostly only useful for separation of taxa within species. Based on the results, P. lacerum Popov is regarded as a synonym of P. commutatum Fisch. & C. A. Mey, while P. piptostigma Bienert ex Fedde, P. halophilum (Fedde) Cullen and P. tubuliferum Fedde are regarded as synonyms of P. macrostomum Boiss. et Huet ex Boiss. var. macrostomum. Further, Papaver gaubae Cullen & Rech. f. and P. bipinnatum C. A. Mey. are included into the synonymy list of P. glaucum Boiss. et Hausskn. and P. arenarium M.‐Bieb., respectively. In contrast, Papaver chelidoniifolium Fisch. & C. A. Mey. var. pinnatum Tavakkoli & Assadi from Gilan province is described as a new variety, and P. rhoeas L. var. strigosum Boenn. and var. glabrum Fedde and P. commutatum subsp. euxinum Kadereit are introduced as new records to Iran. The evolutionary and phylogenetic implications of the observed variation in seed characteristics are also discussed.     

Comparative morphology of leaf epidermis in the Chloranthaceae

Leaf epidermis of 23 samples representing 16 species of all the four extant genera of the Chloranthaceae, i.e. Sarcandra, Chloranthus, Ascarina and Hedyosmum , were investigated under both light microscope and scanning electron microscope. Characters of leaf epidermis in this family, such as pattern of epidermal cells, type of stomata, shape of guard cell pairs and cuticular ornamentation, are usually constant in species and thus of great significance in understanding the relationships between and within genera. The previous viewpoints with either Hedyosmum or Chloranthus shown as having the closest affinity with Ascarina seem to be unreasonable. The phylogeny indicated by DNA sequence analysis, which suggested that Ascarina be the sister group of Sarcandra and Chloranthus , and Hedyosmum the sister of the above three genera, is well supported. Within Chloranthus , the traditional division of the genus on the basis of habit seems to be quite unnatural. Evidence from leaf epidermis, just as that from stem anatomy and cytology as well as sequence analysis of ITS region, strongly suggests the separation of the genus into two groups according to the characteristics of androecial organs.     

中国桑寄生科植物叶表皮微形态

通过扫描电镜对中国桑寄生科桑寄生亚科8属18种和槲寄生亚科1属2种植物成熟叶的上、下叶表皮内表面和下表皮外表面进行了研究。内面观发现桑寄生科植物叶上、下表皮形状为多边形,垂周壁式样平直或稍弓形,常具有角质增厚,平周壁常覆盖厚角质或颗粒状、丝状角质增厚;气孔存在于上下表皮,通常下表皮较多,气孔的形状,特别是保卫细胞的形态在亚科间、属间或种间都具有一定的差异,气孔器类型为平列型或单圈型。下表皮表面观察了的角质膜和蜡质纹饰、气孔的形状,外部气孔缘及外部气孔缘内缘的特征。这些特征在亚科或属级水平上较为稳定,有的也表现出种间差异,有一定的分类价值。从气孔形态和外部气孔周围角质膜来看,两亚科显示出明显的不同:桑寄生亚科上、下表皮均具有内部气孔缘,而槲寄生亚科没有此结构;桑寄生亚科外部气孔周围角质膜增厚成环状,其上具增厚的条纹,而槲寄生亚科外部气孔周围角质膜增厚成脊状,不具条纹。这些特征支持槲寄生亚科作为独立1个科来处理。     

The dangeardien and its significance in the taxonomy of the ascomycetous yeasts

The concept of a dangeardien is discussed in relation to the ascomycetous yeasts. In species of ascomycetous affinity the dangeardien may be expressed not only as the ascus, but also in the taxa showing an alternation of generation in the absence of an ascosporal state, as a site of reduction division. In such cases it is proposed to refer to the dangeardien as a meioconidiophore and to the externally delimited haplophase, as meioconidia. Taxa showing the formation of meioconidiophores are considered to represent perfect states.     

Phylogenetic significance of the pseudoparaphyses in Loculoascomycete taxonomy

The ontogeny of the ascostroma, in particular the centrum structures, has always been regarded as an important criterion in the subdivision of the Loculoascomycetideae (ascomycetous fungi). However, the use of pseudoparaphysis type, cellular or trabeculate, to classify taxa at the ordinal level has been contentious due to the lack of information about their evolution. To determine the phylogenetic significance of the pseudoparaphysis and its variants, DNA sequences of the 18S nuclear rRNA genes from representatives of the orders Pleosporales and Melanommatales were obtained and analyzed. Species with pseudoparaphyses formed a monophyletic group with high statistical confidence. The monophyly of a distinct lineage of species with cellular pseudoparaphyses (the order Pleosporales) is rejected. Likewise, monophyly of a distinct lineage of species with trabeculate pseudoparaphyses (the order Melanommatales) is rejected also. The Pleosporales and Melanommatales are, therefore, not natural orders. The Lophiostomataceae, Phaeosphaeriaceae, and Melanommataceae are most probably polyphyletic, as is the genus Massarina.     

Comparative morphology of the leaf epidermis in Schisandra (Schisandraceae)

The leaf epidermis of 127 samples representing ten species within Schisandra Michaux. and one species of the related genus, Kadsura Kaempf. ex Juss., was investigated using light and scanning electron microscopy. Many characters of the leaf epidermis in Schisandra , such as pattern of epidermal cells, type of stomata, shape of guard cell pairs and cuticular ornamentation, are usually constant within species and thus make good characters for studying the relationship between and within genera. A new character, rim number, of the outer stomatal rim in the genus is introduced. It is shown that double outer stomatal rims occur only in evergreen Schisandra species, whereas a single rim occurs in deciduous species. This character supports the classification of Schisandra into two subgenera based on habit and androecial organs. This classification is also supported by additional morphological and molecular taxonomic characters. Kadsura coccinea (Lem.) Smith A. C. is the most primitive taxon in the related genus Kadsura . The outer stomatal rim of this species also has double rims. Combined with morphological and molecular evidence, this suggests that Schisandra and Kadsura are closely related and may share a recent common ancestor.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 39–56.     

Taxonomy of the genus Ephedra. Significance of stem and leaf epidermis and cuticle

Epidermal and cuticular characters of 30 taxa of Ephedra (including 24 species and six additional varieties) are described and their taxonomic value is discussed.