Scalariform Perforation Plates Research Articles

Systematic and phylogenetic implications of the wood anatomy of six Neotropical genera of Primulaceae

Our main goals were to identify diagnostic characters at the species, genus, and subfamily levels, find anatomical features with potential for future morphological and molecular (combined) phylogenetic analyses, and to reconstruct the evolution of wood anatomical characters in two subfamilies of Primulaceae in a molecular phylogenetic framework. We investigated twenty-seven species from the woody Myrsinoideae (4 genera) and Theophrastoideae (2 genera) using scanning electron, light, and epifluorescence microscopy. Samples were prepared using standard protocols. Based on the wood anatomical characters, we were able to identify synapomorphies and to detect evolutionary trends of interest for the genera and subfamilies. Both subfamilies share the presence of diffuse porosity, simple perforation plates, septate fibres, and scanty paratracheal axial parenchyma. Theophrastoideae species have rays > 10 cells wide and short (< 350 µm) vessel elements, and Myrsinoideae have breakdown areas in rays and longer vessel elements. Ardisia and Stylogyne have scalariform intervessel pits, Myrsine exhibit breakdown areas in rays, and two Cybianthus species from subgenus Weilgetia have distinguishing features (e.g., scalariform perforation plate in C. nemoralis and the absence of rays in C. densiflorus). Overall, when combining characters, we were able to segregate the Neotropical Primulaceae subfamilies and genera from each other and from the subfamily Maesoideae based on wood anatomy.

Morphological analysis of vessel elements for systematic study of three Zingiberaceae tribes.

Zingiberaceae containing over 1,000 species that are divided into four subfamilies and six tribes. In recent decades, there has been an increase in the number of studies about vessel elements in families of monocotyledon. However, there are still few studies of Zingiberaceae tribes. This study aims to establish systematic significance of studying vessel elements in two subfamilies and three tribes of Zingiberaceae. The vegetative organs of 33 species processed were analysed by light and scanning electron microscopy and Principal Component Analysis was used to elucidate genera boundaries. Characteristics of vessel elements, such as the type of perforation plate, the number of bars and type of parietal thickening, are proved to be important for establishing the relationship among taxa. Scalariform perforation plate and the scalariform parietal thickening are frequent in Zingiberaceae and may be a plesiomorphic condition for this taxon. In the Principal Component Analysis, the most significant characters of the vessel elements were: simple perforation plates and partially pitted parietal thickening, found only in Alpinieae tribe, and 40 or more bars composing the plate in Elettariopsis curtisii, Renealmia chrysotricha, Zingiber spectabile, Z. officinale, Curcuma and Globba species. Vessel elements characters of 18 species of Alpinieae, Zingibereae and Globbeae were first described in this work.

A novel device to measure gaseous permeability over a wide range of pressures: characterisation of slip flow for Norway spruce, European beech, and wood-based materials

AbstractA novel device was conceived and built to measure the apparent gaseous permeability of porous media over a large range of permeability values (10−10–10−18m2) and mean pressures (from 1 bar down to ca. 40 mbar). An extensive series of experimental data are presented and analysed for various porous media: (1) Norway spruce (Picea abies) and European beech (Fagus silvatica) in the three anatomical directions, and, for comparison, (2) three simpler porous media, i.e. an autoclaved aerated concrete (AAC, light concrete) and two wood-based panels. For all porous media, the intrinsic permeability, the gas slippage factor, and the effective pore size were determined from the variations of the apparent permeability as a function of mean pressure. These results are in good agreement with those of previous studies for spruce and bring new insights for beech and wood-based materials, in general. For all products, the effective pore sizes identified with the new instrument are closely linked to the medium morphology. In particular, it was found that in spite of the huge anisotropic ratios between wood’s longitudinal and tangential directions, the identified pore size is similar and corresponds to anatomical features: openings in margo for spruce and scalariform perforation plates for beech. Besides, the pore size identified for beech in the radial direction suggests that radial permeability is most probably controlled by the openings in ray cells (either pits or intercellular voids).

WOOD ANATOMY OF SEVEN SPECIES KNOWN AS "PAU-PARA-TUDO" IN BRAZIL

ABSTRACT Different medicinal plant species can be sold under the same common name. Considering the importance of the correct identification, this study aims to separate, using wood anatomy, seven species popularly known as pau-para-tudo. The results show that Drimys brasiliensis is separated from the others by the presence of tracheids. Capsicodendron dinisii hhas scalariform perforation plates and oil cells associated with the axial parenchyma. Axial parenchyma paratracheal vasicentric and in marginal bands beyond the rays' width, can separate Osteophoeum platyspermum from Simaba cedron. Handroanthus serratifolius has the unique presence of the axial unilateral paratracheal parenchyma and storied cell elements (parenchyma, fibers and vessel elements). Rauvolfia sellowii and Leptolobium dasycarpum can be separated by the number of square/upright marginal ray cells, greater in Rauvolfia sellowii. Thus, this work shows that wood anatomy is a valuable tool for species separation, helps with the identification and consequently is important for the quality control of plant product.

Anatomía de la madera de doce especies del bosque mesófilo de montaña del Estado de México

En este estudio se realizó la descripción anatómica de la madera de 12 especies propias del bosque mesófilo de montaña en el Estado de México. Para cada especie se describen los caracteres microscópicos cualitativos y cuantitativos de las maderas. Con base en la relación de Runkel se clasifica la calidad de sus fibras para obtener pulpa para papel. Se dan a conocer las características morfológicas de cada especie, así como sus nombres comunes y distribución nacional. Ocho especies tienen anillos de crecimiento formados por bandas angostas de fibras con lúmenes reducidos y paredes gruesas, o comprimidas radialmente, en la madera tardía. La porosidad es difusa; los vasos son pequeños, con menos de 100 μm de diámetro y numerosos. Varias especies presentaron elementos de vaso con placa de perforación escalariforme. Los elementos de vaso y fibras se clasifican como medianos y largos. En general el parénquima axial es escaso y en siete especies los radios son de tipo heterogéneo I. Estos resultados son parecidos a los obtenidos en otras regiones similares. De acuerdo a la relación de Runkel se determinó que las fibras son de regular a buena calidad para obtener pulpa para papel.

Laurinoxylon chalatenangensis sp. nov. from the Miocene Chalatenango Formation, El Salvador

Fossil woods from Miocene sediments in El Salvador, collected in rocks of the Chalatenango Formation, have yielded a diverse plant assemblage in need of detailed studies. This new report of Laurinoxylon chalatenangensis sp. nov. Cevallos-Ferriz, Cerón-López et Flores-Rocha, is based on the combination of wood anatomical characters like distinct growth rings, diffuse porosity, vessel elements solitary and in multiple radials of 2–4, occasionally larger, simple and occasionally scalariform perforation plate, intervessel pits alternate, large elliptical vessel element-ray pits with reduced borders, septate thin-walled fibers, 1–4 seriate heterocelular rays, axial parenchyma scanty paratracheal, and oil cells associated with rays and among the fibers. Its presence in the Chalatenango Fm., and similarity to the Chiapas Laurinoxylon, suggest that this lineage extended its distribution southwards through the Neoegene. This record adds a new species to the growing list of Neotropical taxa that were present in Mexico prior to the great exchange of biota in the Americas.

Wood anatomy of some members of family Lauraceae with reference to their identification

The wood anatomy of family Lauraceae was examined to evaluate the detailed anatomical characteristics among selected species of Cinnamomum, Litsea and Phoebe collected from the forests of Upper Assam, NE India. The present study showed that wood structure was homogeneous among genera. The common anatomical characteristics among genera seen were: diffuse porous wood, solitary vessels, intervessel pits alternate, scanty paratracheal parenchyma, presence of septate fibres, oil/mucilage cells, homocellular rays and heterocellular rays. Cinnamomum and Litsea species showed variation in anatomical characteristics. Among Cinnamomum species, growth rings were distinct in C. ceicidodaphne and C. zeylanicum, indistinct in C. tamala and C. bejolghota. Confluent parenchyma was present in C. bejolghota and C. zeylanicum. Aggregate rays were present only in C. ceicidodaphne whereas sheath cells were observed in C. bejolghota. Among Litsea species, indistinct growth ring boundaries, spiral thickenings in vessel elements, crystals in fibres, aggregate rays and sheath cells were distinct features of L. monopetala, scalariform perforation plates were present in both L. cubeba and L. salicifolia. However, L. cubeba could be differentiated from L. salicifolia in having perforated ray cells with scalariform perforation.

Middle Eocene trees of the Clarno Petrified Forest, John Day Fossil Beds National Monument, Oregon

One of the iconic fossils of the John Day Fossil Beds National Monument, Oregon, USA, is the Hancock Tree—a permineralized standing tree stump about 0.5 m in diameter and 2.5 m in height, embedded in a lahar of the Clarno Formation of middle Eocene age. We examined the wood anatomy of this stump, together with other permineralized woods and leaf impressions from the same stratigraphic level, to gain an understanding of the vegetation intercepted by the lahar. Wood of the Hancock Tree is characterized by narrow and numerous vessels, exclusively scalariform perforation plates, exclusively uniseriate rays, and diffuse axial parenchyma. These features and the type of vessel-ray parenchyma indicate affinities with the Hamamelidaceae, with closest similarity to the Exbucklandoideae, which is today native to Southeast and East Asia. The Hancock Tree is but one of at least 48 trees entombed in the same mudflow; 14 others have anatomy similar to the Hancock Tree; 20 have anatomy similar to Platanoxylon haydenii (Platanaceae), two resemble Scottoxylon eocenicum (probably in order Urticales). The latter two wood types occur in the nearby Clarno Nut Beds. Two others are distinct types of dicots, one with features seen in the Juglandaceae, the other of unknown affinities, and the rest are very poorly preserved and of unknown affinity. Leaf impressions in and immediately below the layer containing the trees include the extinct genera Macginitiea and Platimeliphyllum (Platanaceae), and Trochodendroides (Saxifragales).

First anatomically characterized wood from the Tertiary of Moravia: Spiroplatanoxylon from the area of Austerlitz (Southern Moravia, Czech Republic)

A new silicified angiosperm wood from the alluvial sediments in Vážany nad Litavou (SW of Slavkov/Austerlitz near Brno, Vyškov district) is described. The wood is diffuse-porous with indistinct growth ring boundaries. Vessels are exclusively solitary with helical thickenings and scalariform perforation plates. Rays are very high and up to 18 cells wide, homocellular to slightly heterocellular. Crystals are present in axial parenchyma mostly in chambered cells, rarely in idioblasts. The fossil is attributed to Spiroplatanoxylon mueller-stollii Süss. Other species of Spiroplatanoxylon are also discussed. Wood anatomical descriptions from the eastern part of the Czech Republic published so far deal either with the Silesian Tertiary or describe only partially lignified probably Quaternary material; therefore the present paper can be considered as the first detailed anatomical description of the Tertiary wood from Moravia.

Origins and nature of vessels in Monocotyledons. 14. Vessellessness in Orontioideae (Araceae): adaptation or relictualism?

SEM studies of tracheary elements of subfamily Orontioideae (Lysichiton, Orontium, Symplocarpus) of Araceae show unexpected features. The plants are entirely vesselless. There are small pores in pit membranes of end walls of tracheids in roots and stems, but pit membranes remain intact. End wall pit membranes of stems have a coarse fibrillar texture, somewhat reminiscent of (but different from) those of Nymphaeaceae and Cabombaceae. Acoraceae, which are also vesselless, represent the first branch of the monocot tree, according to phylogenies, and the orontioids form the next branch. Vessellessness is therefore a potentially plesiomorphic feature in monocots, but it may also be related to the highly mesic habitats of Acoraceae and the orontioids. Various other non‐submersed monocots have vesselless or near‐vesselless xylem. Sectioned xylem of Orontioideae is also very suggestive of stages in the development of the pit membranes of both end walls and lateral walls of tracheids: open networks of cellulosic fibrils apparently precede the addition of denser fibrillar meshes, key information in assessing to what extent perforations in scalariform perforation plates of vascular plants may stop formation at the open network stage, and to what extent a thicker pit membrane experiences lysis and disintegration as the vessel element matures.

A new species of Antarctoxylon: a contribution to the early angiosperm ecosystem of Antarctica during the late Cretaceous

AbstractA new species of Antarctoxylon is described from the Coniacian Hidden Lake Formation of James Ross Island as A. mixai Sakala, sp. nov. This angiosperm fossil wood shows a unique combination of features in having indistinct growth ring boundaries, scalariform perforation plates with about 30 bars and rays both narrow (1–6-seriate) and very wide (up to 18-seriate). Its systematic affinities and exact living relative at the specific, generic or even familial level cannot be specified. Along with Weinmannioxylon nordenskjoeldii from James Ross Island and the angiosperm woods from the Williams Point on Livingston Island, this record provides further evidence of the earliest record of arboreal angiosperms in Antarctica.

Hydraulic engineering of the angiosperm leaf: do the Baileyan trends in perforation plate evolution account for the origin of high vein density?

Hydraulic engineering of the angiosperm leaf: do the Baileyan trends in perforation plate evolution account for the origin of high vein density?

Comparative wood anatomy of Rhodothamnus species

In this study, the comparative wood anatomy of the European [Rhodothamnus chamaecistus (L.) Reichb.] and Anatolian (Rhodothamnus sessilifolius P.H.Davis) species of Rhodothamnus were studied. The wood anatomy of the taxa shows evidence of adaptation to growing in alpine habitats. The woods of the species exhibit primitive wood anatomical characteristics and share similar qualitative anatomical features. However, some of the quantitative anatomical characteristics of the taxa show significant differences, such as the distinctness of the growth ring and the bar number of the scalariform perforation plate. The present study describes and compares the anatomical properties of the wood of the Rhodothamnus species.

Virtual Special Issue (VSI) on whole‐plant water transport

Virtual Special Issue (VSI) on whole‐plant water transport

How wood evolves: a new synthesis

Recent advances in wood physiology, molecular phylogeny, and ultrastructure (chiefly scanning electron microscopy, SEM), as well as important new knowledge in traditional fields, provide the basis for a new vision of how wood evolves. Woody angiosperms have, in the main, shifted from conductive safety to conductive efficiency (with many variations and modifications) and from ability to resist cavitation (low vulnerability) to ability to refill vessels. The invention of the vessel was a kind of dimorphism (vessel elements plus tracheids) that permitted division of labor and many kinds of wood repatterning that suit conductive safety–efficiency trade-offs. Angiosperms were primarily adapted to mesic habitats but were not failures or “unstable.” They have survived to the present in such habitats well, along with older structural adaptations (e.g., the scalariform perforation plate) that are still suited to such habitats. These “primitive” features are evident in earlier branchings of phylogenetic trees based on multiple genes. Older features may still be functional and thus persist, although newer formulations are overriding in effect. There are, however, numerous instances of “breakouts” in a number of clades (ecological iterations and bursts of speciation and diversification related to new ways of dealing with water economy), whereas in other branchings, other clades show ecological stasis over long periods of time. Newer physiological and anatomical mechanisms have permitted entry into habitats with marked fluctuation in moisture availability. Wood evolves progressively, and literal character state reversal may be unusual: genomic and developmental information holds answers to these changes. Wood is a complex tissue, and each of the histological components shows polymorphism as an evolutionary mechanism. Cell types within wood evolve collaboratively. Shifts in wood features (e.g., simplification of the scalariform perforation plate) are commonly homoplastic. Manifold changes in habit and in leaf physiology, morphology, and anatomy accompany wood evolution, and wood should be studied with relationship to real-world ecology, information that cannot be gleaned from literature or other secondary sources. Heterochrony (protracted juvenilism, accelerated adulthood) characterizes angiosperm xylem extensively, far more so than in other vascular plants, and these mechanisms have resulted in many remarkable changes (e.g., monocots have permanently juvenile xylem, woody trees represent accelerated adulthood). Understanding the many successful features of angiosperm wood evolution must ultimately rest on syntheses.

A diverse charcoalified assemblage of Cretaceous (Santonian) angiosperm woods from Upatoi Creek, Georgia, USA. Part 1: Wood types with scalariform perforation plates

This paper is the first in a series describing a diverse assemblage of charcoalified angiosperm woods from the Cretaceous (early to mid-Santonian) Eutaw Formation at Upatoi Creek, Georgia, USA. In our study, we separated ‘twigs’ from more ‘mature’ woods and further subdivided the latter material into specimens showing scalariform and simple perforation plates. Here, we report on thirteen ‘mature’ specimens with scalariform perforation plates. For such a small sample size, there is a remarkable diversity, with seven more or less distinct wood types present including two new taxa: Gregoryoxylon georgiaensis gen. et. sp. nov. and Chaloneroxylon pagei gen. et. sp. nov. The seven wood types are similar to most previously reported specimens from the Turonian–Santonian interval, i.e., they are diffuse porous, with predominantly solitary vessels, heterocellular rays, and only diffuse and/or scanty paratracheal parenchyma. None of the seven Upatoi wood types has a combination of features that allows unequivocal assignment to a single extant family. Chaloneroxylon may represent a record of the Magnoliaceae; of the other unnamed wood types, one has features found in the asterid orders Cornales and Ericales, while two possibly are referred to the Malpighiales. The affinities of the remaining three wood types, including Gregoryoxylon, are uncertain. The cryptic affinity of these woods is significant in itself, reflecting their Cretaceous age, a time when extant families were still rapidly diversifying.

Wood anatomical variations in some species of Quercus of Meghalaya

The main aim of present study is to gather original information on anatomical features and variations in dimensions of wood elements of some Quercus species of Meghalaya. All species of Quercus show diffuse porous wood with indistinct growth rings except Q. acutissima which shows tendency towards semi ring porous and Q. semiserrata with fairly distinct growth rings. Vessels are solitary or radial multiple of two arranged in radial or diagonal pattern. All species of Quercus show presence of scalariform perforation plates and vasicentric tracheids. Aggregate rays are present only in Q. acutissima where as Q. lanceofolia and Q. semiserrata show the presence of multiseriate rays. Both homocellular and heterocellular rays are present in Quercus species except Q. acutissima and Q. fenestrata which show only heterocellular rays. Axial parenchyma is apotracheal diffuse in all species except Q. acutissima that shows diffuse in aggregate, banded and unilateral paratracheal parenchyma in addition to apotracheal diffuse. Chambered crystals are present in Q. dealbata and Q. fenestrata.Tissue proportion of different wood elements shows that fiber percentage is maximum in all species. Variance ratio (F test) indicates that there are statistically significant differences in wood elements dimension namely fiber length, fiber diameter, vessel diameter, vessel density and wood density. Also a positive and significant correlation exists between fiber diameter and wall thickness while other parameters are not correlated with each other.

Comparative Wood Anatomy of Stem and Root in Korean-grown Yellow-poplar (Liriodendron tulipipfera L.)

This study was carried out to offer basic information on the wood anatomy of domestic yellow-poplar (Liriodendron tulipifera L.), a new plantation species selected by Korea Forest Service as one of the promising hardwood and bioenergy sources of the future, through comparison of stem wood with root wood in the qualitative and quantitative features. In the qualitative anatomical features, growth rings were distinct in stem wood but relatively less distinct in root wood. And stem wood appeared to have pores in radial multiples of 2 to 5, sometimes clusters but root wood to have pores in radial multiples of 2 to 3, rarely clusters. And numbers of bars in scalariform perforation plates were somewhat numerous in vessel elements of root wood than in those of stem wood. Interestingly, on the other hand, more extraneous materials in the wood rays of tap root than in those of lateral root and stem were confirmed in the chemical composition analyses. In the quantitative anatomical features, pore densities were significantly greater but vessel elements were considerably narrower in stem wood than in root wood. Vessel elements and wood fibers of root wood were considerably longer than those of stem wood. Rays were somewhat more numerous in stem wood than in root wood, and only ray heights of stem wood were more or less greater in cell numbers but both ray heights and widths of stem wood were lower in dimension than those of root wood. The anatomical differences between stem wood and root wood were thought to be associated with different growth environments between the stem above ground and the root below ground.

The Ecophysiology of Xylem Hydraulic Constraints by “Basal” Vessels in Canella winterana (Canellaceae)

Early angiosperms are hypothesized as constrained to wet environments where many of their defining characteristics evolved. A functional capability potentially enforcing the wet habitation of early angiosperms was possession of xylem with low hydraulic capability and drought intolerance. Recent studies indicate that a structural hallmark of these performances is long, steeply angled scalariform perforation plates in extant basal angiosperms. However, Canella winterana (Canellaceae), a magnoliid, appears to have radiated into much drier tropical dry forest habitats despite possessing a wood vasculature structurally similar to hypothesized ancestral wet-adapted system for angiosperms as a whole. Based on a field study of Canella wood hydraulic function, we present ecophysiological data that basal vessels do not necessarily mark low resistance to drought. We found that Canella wood was resistant to drought-induced cavitation. Leaf hydraulic capacity as well as leaf pressure-volume relations and leaf water potential minima found for Canella were comparable to some of the most drought-tolerant tropical dry forest angiosperms. Thus, our results suggest that vessels of an ancestral design can be exported to dry environments. We found that scalariform-plated vessels in Canella were associated with low hydraulic capacities at the xylem and whole shoot-scales as well as limited plasticity of the xylem to varying hydrodynamic demand. Consequently, our results support the hypothesis that evolution of simple perforation plates, not vessels per se, represented a critical adaptation for producing large hydraulic gains during angiosperm evolution across a broader range of environments.

Wood and bark anatomy of Centella: scalariform perforation plates support an affinity with the subfamily Mackinlayoideae (Apiaceae)

Detailed descriptions of the wood and bark anatomy of five representative Centella species are presented. The wood structure is reported for the first time for this genus. Scalariform perforation plates occur frequently in the secondary xylem of two Centella species (Centella difformis and C. rupestris) indicating a phylogenetic relationship with Apiopetalum and Mackinlaya, the only other genera of Apiaceae where this feature occurs regularly and not merely as an aberration. This character commonly occurs in two other families of Apiales, Araliaceae and Myodocarpaceae, supporting the presumed basal position of subfamily Mackinlayoidae within Apiaceae. Surprisingly, no axial secretory canals occur in the secondary phloem of Centella species, apparently a unique feature within the suborder Apiineae, which comprises Araliaceae, Myodocarpaceae, Pittosporaceae, and Apiaceae. Other noteworthy characters of Centella include subepidermal origin of the periderm, tangential expansion of rays in dilated secondary phloem, poorly sclerified or non-sclerified collapsed secondary phloem, small intervessel pits with groove-like sculptures near their apertures, diffuse and marginal axial parenchyma, and a predominance of upright and square cells in the ray composition, all of which may be of value in exploring infrageneric relationships.