Septate Fibres Research Articles

Fossil woods from the late Campanian–early Maastrichtian Olmos Formation, Coahuila, Mexico

Three fossil wood types are described from the Olmos Formation, Coahuila, Mexico. The anatomical characters of two of them enable identification to Malvaceae and Fagaceae, while the affiliation of the third type is uncertain (Fagaceae?). The wood of the Malvaceae fossil plant is characterised by the presence of vessel-ray and vessel-parenchyma pits with reduced borders, larger than the intervascular pits, scanty paratracheal parenchyma, septate fibres and storied structure. This wood type, Javelinoxylon, has been also found in the Maastrichtian Javelina Formation, Texas. Aggregate and uniseriate homocellular rays, apotracheal diffuse and diffuse in aggregates parenchyma, simple perforation plates, vessel-ray pits variable with reduced borders and vasicentric tracheids relate the wood of a second plant to Quercinium. The third wood type, Sabinoxylon pasac Estrada-Ruiz, Martínez-Cabrera et Cevallos-Ferriz, is very similar to some species of Quercinium; however, the presence of heterocellular rays and the almost exclusive presence of scalariform perforation plates make unlikely its relationship with this genus. Since observation of vessel parenchyma and vessel ray pits was not possible, its inclusion in Fagaceae cannot be confirmed. Nevertheless, S. pasac and Quercinium centenoae Estrada-Ruiz, Martínez-Cabrera et Cevallos-Ferriz represent the earliest record of fagaceous plants in Mexico, while the presence of Javelinoxylon weberi Estrada-Ruiz, Martínez-Cabrera et Cevallos-Ferriz extends the geographic distribution of the genus in North America.

Wood Anatomy of the Tribe Caesalpinieae (Leguminosae, Caesalpinioideae) in Venezuela

We studied the microscopic wood anatomy of 8 genera and 30 species in the tribe Caesalpinieae, subfamily Caesalpinioideae, with a focus on the identification and comparative anatomy of these genera. Characters suitable for reliable identification include intervessel pit size, fibre wall thickness, septate fibres, storied structure, ray type, ray width, and silica bodies. A table of diagnostic characters, generic descriptions, and photomicrographs provide tools for identification and descriptive information for comparative and phylogenetic studies.

Anatomia comparada do pulvino, pecíolo e raque de Pterodon pubescens Benth. (Fabaceae - Faboideae)

Em Pterodon pubescens, os pulvinos primário e secundário, órgãos responsáveis pelos movimentos foliares, apresentam peculiaridades estruturais em relação ao pecíolo e raque. Estas peculiaridades incluem cutícula mais espessa, córtex mais desenvolvido formado por células parenquimáticas de formas variáveis, sistema vascular em posição central, floema circundado por fibras septadas não lignificadas e medula parenquimática reduzida ou ausente. Pecíolo e raque apresentam córtex reduzido constituído por células parenquimáticas isodiamétricas, sistema vascular periférico, floema envolvido por calota de fibras gelatinosas e medula ampla. Compostos fenólicos foram detectados no vacúolo das células corticais dos pulvinos, enquanto que no córtex e medula do pecíolo e da raque foram observados amiloplastos em abundância e ausência de compostos fenólicos. Em geral, as características estruturais do pulvino de P. pubescens são comuns aos pulvinos das demais espécies de Fabaceae e têm sido relacionadas com a intensificação de trocas laterais de íons e água entre células do córtex e sistema vascular, além de proporcionar maior flexibilidade e capacidade de movimento desta região. Já as características do pecíolo e da raque conferem maior rigidez a estas estruturas foliares.

Anatomia e ultra-estrutura do pulvino primário de Pterodon pubescens Benth. (Fabaceae - Faboideae)

The anatomy and ultrastructure of Pterodon pubescens primary pulvinus were studied to verify if slow leaf movements are associated with pulvinus cells features. Pulvini samples deriving from leaf with open and closed leaflets were prepared following usual techniques using light and electron microscopy. The pulvinus has a unisseriated epidermis covered by a thick cuticle and many trichomes, cortex with several layers of parenchyma cells (motor cells), a central vascular core surrounded by septate fibers, and a reduced pith. Cortical cells features change with the turgescence degree, showing alteration in the cell size and shape, cell wall thickness, frequency and arrangement of plasmodesmata, vacuole content and number and cytoplasm density. Septate fibers around the phloem were described for the first time in pulvini. The wide occurrence of plasmodesmata, the apoplastic barriers absence and the lignification scarcity (only present in xylem vessels) indicate a continuity, both simplastic and apoplastic, from the epidermis to the vascular tissue of the pulvinus. In Pterodon pubescens, primary pulvinus features are compatible with slow movement pulvini; the features shared to speedy movement pulvini are the presence of vacuoles with phenolic substances in the cortical cells and amiloplasts in the endodermal cells. Movements caused by P. pubescens primary pulvinus are associated with changes in both the apoplastic (wall infoldings) and symplastic (vacuolar reorganization).

NEW SPECIES OF TAPIRIRA (ANACARDIACEAE) FROM EARLY MIOCENE SEDIMENTS OF THE EL CIEN FORMATION, BAJA CALIFORNIA SUR, MEXICO

From the early Miocene El Cien Formation, Baja California Sur, Mexico, a new Tapirira species is described. Among the diagnostic features that relate T. peninsularis Martínez-Cabrera & Cevallos-Ferriz sp. nov. with extant species of the genus are libriform septate fibers, radial canals with 2–4 layers of epithelial cells, and scanty paratracheal to vasicentric axial parenchyma. In order to establish similarity between wood of T. peninsularis and fossil and extant species of the genus, cluster and principal component analyses were carried out. Numerical analyses support that Tapirira peninsularis is distinct from other extant and fossil species of the genus. Quantitative characters like frequency of radial canals, diameter of fibres, vessel element lumen, and height and width of the rays with radial canals are important in distinguishing between these taxa. Though these wood characters are quantitative, they also have been useful in the recognition of two subgenera within the genus. Recognition of this new species, along with the fossil record of the group, and a phytogeographic analysis suggest a low latitude North American origin for the genus, and a subsequent introduction to southern latitudes.

Anatomia do lenho de espécies do gênero Nectandra Rol. ex Rottb. (Lauraceae)

RESUMO Neste trabalho é apresentada a descrição anatômica do lenho de Nectandra leucantha Nees, Nectandra puberula (Schott) Nees e Nectandra rigida (H. B. K.) Nees. As três espécies apresentaram camadas de crescimento distintas; porosidade difusa; parênquima axial paratraqueal; placas de perfuração simples e escalariformes; pontoações intervasculares alternas e fibras septadas. As características que se mostraram úteis para a segregação das espécies foram: tipo e distribuição do parênquima axial, formato das pontoações intervasculares e presença de células oleíferas/ mucilaginosas.

EARLY LINEAGES IN APIALES: INSIGHTS FROM MORPHOLOGY, WOOD ANATOMY AND MOLECULAR DATA

Recent molecular studies indicate that the araliaceous tribes Myodocarpeae R. Vig. (Delarbrea Vieill., Pseudosciadium Baill. and Myodocarpus Brongn. & Gris.) and Mackinlayeae R. Vig. (Apiopetalum Baill., Mackinlaya F. Muell. and several genera of Hydrocotyloideae Link (Apiaceae)) comprise basally branching lineages within Apiales, an interpretation consistent with data from morphology and wood anatomy. Comparison of selected features in these genera, and in close relatives of Apiales, suggests that ancestral character states for the order may include: simple leaves, inflorescences in panicles of umbellules, flowers with articulated pedicels and a bicarpellate gynoecium, an andromonoecious, duodichogamous sexual system, septate fibres, the absence of radial canals, and the presence of paratracheal axial parenchyma in the wood.

PHYLOGENETIC RELATIONSHIPS WITHIN APIALES: EVIDENCE FROM WOOD ANATOMY

Wood anatomical data confirm the close relationships of most Araliaceae to Apiaceae, but do not indicate any intermediate groups between the two families. Heteromorpha Cham. & Schltdl., Bupleurum L. and Melanoselinum Hoffm. form a well-delimited group distinguished from other woody Apiaceae by helical thickenings on their vessel walls, septate fibres, and mostly homogeneous rays. The woodiness in Nirarathamnos Balf.f. and Myrrhidendron J. M. Coult. & Rose is likely to be of secondary origin.

Monimiaceae sensu lato, an element of Gondwanan polar forests: Evidence from the late Cretaceous-early tertiary wood flora of Antarctica

Palaeofloristic studies of the Antarctic Peninsula region are important in furthering our understanding of (i) the radiation and rise to ecological dominance of the angiosperms in the Southern Hemisphere during the Late Cretaceous and (ii) the present day disjunct austral vegetation. Investigations of Upper Cretaceous and Early Tertiary sediments of this region yield a rich assemblage of well-preserved fossil dicotyledonous angiosperm wood which provides evidence for the existence, since the Late Cretaceous, of temperate forests similar in composition to those found in present-day southern South America, New Zealand and Australia. This paper describes two previously unrecognised morphotypes, which can be assigned to the Monimiaceae sensu lato, and represents the first record of this family in the wood flora of Antarctica. Specimens belonging to the first fossil morphotype have been assigned to Hedycaryoxylon SÜss (subfamily Monimioideae) because they exhibit anatomical features characteristic of Hedycaryoxylon and extant Hedycarya J.R.Forst. & G.Forst. and Tambourissa Sonn. Characters include diffuse porosity, vessels which are mainly solitary with scalariform perforation plates, opposite to scalariform intervascular pitting, paratracheal parenchyma, septate fibres and tall (>3 mm), wide multiseriate rays with a length: breadth ratio of approximately 1: 4. Specimens belonging to the second morphotype have been assigned to Atherospermoxylon KrÄusel, erected for fossil woods of the Monimiaceae in the tribe Atherospermeae (now Atherospermataceae) in that they exhibit anatomical features similar to Atherospermoxylon and extant Daphnandra Benth., Doryphora Endl. and Laurelia novae-zelandiae A.Cunn. These characters include diffuse to semi-ring porosity, scalariform perforation plates with up to 25 bars, septate fibres, relatively short (<1 mm) rays with a length: breadth ratio of between 1: 4 and 1: 11.

WOOD ANATOMY OF SCHEFFLERA AND RELATED TAXA (ARALIACEAE). II. SYSTEMATIC WOOD ANATOMY OF NEW CALEDONIAN SCHEFFLERA

The wood anatomy of 22 of the 26 species of Schefflera occurring in New Caledonia was studied. Only two features (the presence of scalariform perforation plates and scanty paratracheal axial parenchyma) appear to be constant throughout the species examined. The pattern of wood structure diversity was analyzed using PCA; the results generally agree with the current recognition of four groups of species among New Caledonian Schefflera based on macromorphology. Three of these groups (Dizygotheca, “Canacoschefflera” and “Gabriellae”) represent natural assemblages closely related to one another. The fourth group (Schefflera sect. Schefflera) is isolated from the others, as indicated by its very large rays and abundant septate fibres. The occurrence of crystals in chambered cells of axial parenchyma was observed for the first time in Araliaceae. The wood structure of Schefflera plerandroides, previously placed in the segregate genus Octotheca, shows no essential differences from that of the other members of the Dizygotheca group, supporting the hypothesis that polymerous flowers have evolved independently at least twice within the Schefflera alliance.

Contributions to the Wood Anatomy of the Rubioideae (Rubiaceae)

The secondary xylem of Craterispermeae, Coussareeae, Morindeae s.str., Prismatomerideae, Pauridiantheae, Urophylleae, and Triainolepideae (Rubiaceae, Rubioideae) is described and illustrated in detail. Genera that were previously placed in the Morindeae or Psychotrieae such as Damnacanthus, Lasianthus, Saldinia, and Trichosfachys are also included. Wood anatomical characters are compared with recent phylogenetic insights into the study group on the basis of molecular data. The observations demonstrate that the delimitation and separation of several taxa from the former Coussareeae/Morindeae/Prismatomerideae/Psychotrieae aggregate is supported by wood anatomical data. The Coussareeae can be distinguished from the other Rubioideae by their scanty parenchyma, septate libriform fibres, and the combination of uniseriate and very high multiseriate rays with sheath cells. Axial parenchyma bands and fibre-tracheids characterise Gynochtodes and some species of Morinda (Morindeae sstr.), but the latter genus is variable with respect to several features (e.g. vessel groupings and axial parenchyma distribution). Wood data support separation of Rennelia and Prismatomeris from Morindeae s.str.; vessels in both genera are exclusively solitary and axial parenchyma is always diffuse to diffuse-in-aggregates. Damnacanthus differs from the Morindeae alliance by the occurrence of septate fibres, absence of axial parenchyma, and the occasional presence of fibre wall thickenings. There are interesting similarities between members of the Lasianfhus clade and the Pauridiantheae/Urophyleae group such as the sporadic occurrence of spiral thickenings in axial parenchyma cells.

NUCLEATED XYLEM FIBERS IN SOME INDIAN SPECIES

Xylem fibers were found to have retained their nucleus in 27 species of 17 genera. These fibers were characterized by thick lignified walls with narrow lumen and tapering ends. Their length and width varied among the species studied and were greatest in Phyllanthes emblica Linn. and least in Antigonon leptopus H. & A. Depending on the species, the fibers were either septate or nonseptate. Each compartment of the septate fibers was accompanied by a single nucleus. The nuclei of these fibers were oval to oblong or fusiform in shape. Accumulation of starch in the lumina of the nucleated fibers was a common feature in all the species. Occurrence of nucleated fibers and its possible significance is discussed.

Wood Anatomy of Selected West African Species of Caesalpinioideae and Mimosoideae (Leguminosae): A Comparative Study

Leguminosae constitute an important proportion of the charcoal sampIes recovered at archaeological sites in the West African savannas. Identification of these fragments to a level below family or subfamily was problematic, because a comparative survey was missing. Therefore, the wood anatomy of 31 species (23 genera) of Mimosoideae and Caesalpinioideae growing in the Sudanian savannas of West Africa was examined. The species were grouped into 18 types according to wood anatomical structure. The types represent single species or genera (fourteen types), two genera (three types) or three genera (one type) . The following features are regarded as suitable for a reliable delimitation and identification . Heterocellular rays and storied structure allow for a first differentiation. Enlarged, non-bordered vessel-ray pitting , nonvestured vessel-pits, silica, axial canals, septate fibres and crystals in non-eharnbered ray cells are additional features characterizing few or single types. Types without these features are delimited less easily. Parenchyma distribution and ray width are, due to variability, not as reliable , but remain necessary features for identification. Types characterized by these features only may not always be recognized correctly. Quantitative features of the vessels are not regarded as helpful for the differentiation within the set of examined species. A table (Table 1) summarizes the results for easy reference.

The Seasonal Occurrence and Histology of Septate Fibers in Kalopanax Pictus

Septate wood fibers were abundant in the following parts of growth rings of Kalopanax pictus Nakai: 1) around the vessels, 2) in the vicinity of ray cells, 3) in terminal regions of the growth rings. Septum formation in wood fibers progressed from the initial region (pore zone) towards the terminal region within a current growth ring with progressing 1ignification of the wood fiber walls. Many septate wood fibers at the end of the growth ring had radially continuous septa. Karyokinesis was observed in severa1 wood fibers before the initiation of septum formation, while lignification was in progress after the completion of the S3 layer deposition. This suggests that the septation starts in parallel with the progress of lignification after the deposition of the S3 layer.

Wood Anatomy of the Hippocrateoideae (Celastraceae)

In this paper the wood anatomy of the subfarnily Hippocrateoideae of the Celastraceae is treated. Halle's division (1986, 1990) of the subfarnily into four tribes, chiefly based on material of tropical Africa: viz. Salacieae, Campylostemoneae, Helictonemeae and Hippocrateae is followed. In a recent issue of the Flora of the Guianas the Hippocrateaceae - there treated as aseparate farnily - were divided into Hippocrateoideae and Salacioideae. This bipartition was reflected in the wood structure of the genera studied (Mennega 1994). Here the wood structure of all genera worldwide (24), except the Asian genus Arnicratea, is described. It appeared that again a subdivision into two distinct anatomical groups could be made, with the three last tribes mentioned above showing the same characteristic structure as found before in New World Hippocrateae/Hippocrateoideae. The most important features of this group are the presence of very wide and very high rays, in a number of genera with unlignified ray cells at the growth ring border, the absence of included phloem tissue, and in many species an intruding bark resulting in an indented wood pattern in stern cross sections or even an intricate pattern of deep furrows. The Salacieae/Salacioideae on the other hand are characterized by narrow, not exceptionally high rays, absence of unlignified ray cells, the occurrence of septate fibres in a parenchyma-like distribution, and often by the presence of included phloem tissue, either as isolated strands or more often as conspicuous concentric bands, or as irregular bands with radial connections. Features present in all genera are: vessels with simple perforation plates, preponderance of solitary vessels, wide and narrow vessels distributed at random, alternate pitting; fibretracheids, and libriform nonseptate and septate fibres present; axial parenchyma scanty paratracheal or as rare isolated strands; rays heterogeneous, the cell types irregularly distributed, rhombic crystals numerous, often in characteristic radial distribution. Campylostemon, considered in the past by some taxonornists as belonging in Celastraceae or as intermediate between Hippocrateaceae and Celastraceae, closely resembles Hippocrateae in its wood anatomy. And it is especially this group that by its characteristic features -like the wide rays - is more different from Celastraceae in general than Salacieae, which have several features in common with genera of Celastraceae.

Wood Anatomy of Akaniaceae and Bretschneideraceae: A Case of Near-Identity and Its Systematic Implications

Wood anatomy is described in detail for the single-species families Akaniaceae and Bretschneideraceae, placed close together in most phylogenetic systems. Both families have simple perfora- tion plates with occasional scalariform plates, alternate lateral wall pitting, helical sculpturing on vessel walls, septate fibers with pits simple or nearly so, scanty vasicentric axial parenchyma, and wide tall multiseriate rays composed mostly of procumbent cells. Differences between the genera are relatively few and minor compared with resemblances; close relationship is indicated. Wood anatomy of the two families resembles that of Sabiaceae and, to a lesser extent, that of other Sapindales. The wood is distinctive within Capparales whether that order is defined traditionally or in the light of molecular studies. Wood data are compatible with an interpretation that Akaniaceae and Bretschneideraceae diverged from near the base of Sapindales.

Wood Structure and Generic Status of Some Southern African Cassinoideae (Celastraceae)

Opinions differ on whether to treat Cassine in southern Africa in a wide sense, or to recognise several segregate genera, such as Elaeodendron, Crocoxylon, Lauridia, Mystroxylon and Cassine s. str. A comparative anatomical study was made of mature wood representing 17 southern African species of Cassine s.l., Pleurostylia and the three monotypic genera, Allocassine, Hartogiella and Maurocenia (all members of the subfamily Cassinoideae). The wood structure is described with emphasis on the taxonomic value of quantitative and qualitative characters. Various features were found to be diagnostic at supraspecific level. The presence or absence of scalariform perforation plates, septate fibres, various ray types, and additional quantitative characters could be useful for taxonomic application, especially for generic delimitation. Three principal wood types, of which one encompasses three subtypes, are recognised among the species examined. Wood anatomical evidence tells against a wide generic concept for Cassine, and favours the recognition of segregate genera.

Wood anatomy of selected Cucurbitaceae and its relationship to habit and systematics

Qualitive and quantitative data are presented on wood anatomy and cambial conformations of four species of Cucurbitaceae. Although all woody to various degrees, the four species were selected to show a wide range of habits and therefore to discern possible correlations between habit and wood anatomy. Vessels are widely spaced and libriform fibers are minimal where storage of water and carbohydrates is prominent. Axial parenchyma is dimorphic: lignified thick-walled paratracheal may lend strength to the vessel elements (which are wider than long), whereas thin-walled apotracheal parenchyma may lend flexibility to stems (especially in lianoid species) and serve for storage. Rays are multiseriate only and alter little from primary rays (but large multiseriate rays originate suddently in fascicular areas of one species). Distribution and abundance of libriform fibers relate to habit: most abundant in the shrubby Acanthosicyos, least in the storage-oriented lower stems of Apondanthera). Vasicentric tracheids extend radially and interconnect vessels, potentially providing a subsidiary conductive system that would maintain the conductive pathways of the large vessels if some of those vessels were to be disabled or deactivated. Cucurbitaceae are characterized by septate fibers, vasicentric tracheids, and storied wood structure. Each of these features is found in at least half of the families now commonly included in Violales, to which Cucurbitaceae are thought to belong.

Wood Anatomy of Trees and Shrubs from China. IV. Ulmaceae

The wood anatomy of 37 species belonging to the eight genera of Ulmaceae native to China is described. The wood of Chinese Ulmaceae is characterised by mostly simple perforations (sporadic scalariform plates occur in Hemiptelea and Zelkova); altemate, non-vestured intervessel pits; relatively short vessel elements and fibres; non septate fibres with simple to minutely bordered pits confined to the radial walls; mainly paratracheal parenchyma; rays rarely higher than 1 mm. Tanniniferous tubes are reported for the first time in Ulmaceae; they are limited to the genus Pteroceltis. Other, sporadically occurring features such as perforated ray and axial parenchyma cells and perforated fibres are also reported for the first time.

Wood Anatomy of the Bignoniaceae, with a Comparison of Trees and Lianas

The secondary xylem anatomy of trees and lianas was compared in the family Bignoniaceae. General descriptions of the family and the six woody tribes are provided. Lianas belong to the tribes Bignonieae, Tecomeae and Schlegelieae, and most have ve.ssels of two distinct diameters, many vessels per unit area, large intervascular pits, septate fibres, large heterocellular rays often of two distinct sizes, scanty paratracheal and vasicentric axial parenchyma and anomalous growth. Conversely, trees, which belong to the tribes Coleeae, Crescentieae, Oroxyleae and Tecomeae generally have narrower vessels in one diameter class, fewer vessels per unit area, smaller intervascular pits, non-septate fibres, small homocellular rays, scanty paratracheal, aliform or confluent parenchyma, and none exhibits anomalous growth. The majority of both trees and Hanas possess growth rings, are diffuse-porous, have non-solitary vessels which lack helical thickenings, and few have apotracheal parenchyma or storied structure. All species have alternate intervascular pitting and simple perforation plates.