Multiseriate Rays Research Articles

Wood anatomy of five species from Mozambique and its potential application

SUMMARY: Wood trade is strongly dependent on global economic conditions. In Africa, the market for tropical wood also has dynamic changes. In Mozambique, the international demand for wood comes mainly from emerging economies such as China and India. Almost 70 % of the country is still covered by forests and other woody vegetation. There are many species with favorable properties for wood commerce, although, at present, this is restricted to a few species. We analyzed the wood anatomy of Acacia nigrescens, Combretum imberbe, Icuria dunensis, Pericopsis angolensis and Sterculia appendiculata and comment about properties and potential use based on their anatomical composition. In general, the species presented wood diffuse pores, simple perforation plates, alternate intervessel pits, deposits in vessels; abundant axial parenchyma; multiseriate rays, very thick-walled fibers and mineral inclusions. Based on anatomical characteristics, the studied species have great potential for use in panels industry, furniture, floor, structures and craftwork.

A new genus of Anacardiaceae fossil wood from El Bosque Formation (Eocene), Chiapas, Mexico

ABSTRACTWe describe a new fossil wood from the El Bosque Formation (Eocene) in Chiapas, southern Mexico. It has a combination of features found in the Anacardiaceae, including distinct growth rings, diffuse porosity, vessels solitary and in radial multiples of 2–3, simple perforation plates, medium to large alternate intervessel pits, vessel-ray parenchyma pits rounded and elongate with reduced borders, septate and non-septate fibers, axial parenchyma scanty paratracheal, vasicentric, apotracheal diffuse, Kribs heterogeneous rays type IIA, and multiseriate rays with radial canals. The mosaic of features of this wood supports the erection of a new genus, Bosquesoxylon Pérez-Lara, Castañeda-Posadas et Estrada-Ruiz. This new genus of anacardiaceous fossil wood extends our knowledge of this family’s history and offers hints on the possible relationships with floras from other localities worldwide, especially North America and Asia.

Fossil woods of Detarioideae subfamily (Fabaceae) from El Palmar Formation (Late Pleistocene) in South America

The main aim of the present paper is to describe the first Detarioideae fossil woods from El Palmar Formation (Late Pleistocene) in the Uruguay River Basin (Entre Ríos, Argentina). This study is based on five silicified wood specimens preserved in fluvial deposits, which were transported from their growth site. Two new genera and species are described: Paraoxystigma concordiensis gen. nov and sp. nov. has medium-sized vessels, paratracheal axial parenchyma, heterocellular and multiseriate rays, and diffuse axial canals similar in size and shape to vessels, and Gossweilerodendroxylon palmariensis gen. nov and sp. nov. has medium-sized vessels, alternate intervessel pits, paratracheal and apotracheal axial parenchyma, homocellular and uni to-multiseriate rays, and small diffuse axial canals. These Detarioideae fossil records in south-eastern South America support the existence of a very old relationship with the extant West African forests. Eco-anatomical features observed in these fossil woods, along with the climatic information available from the Nearest Living Relatives (NLRs) comparison, suggest warm and humid climatic conditions for the upper-middle basin of the Uruguay River during some periods of the Late Pleistocene.

Evolution of wood anatomical characters in Nepenthes and close relatives of Caryophyllales.

Nepenthes attracts wide attention with its spectacularly shaped carnivorous pitchers, cultural value and horticultural curiosity. Despite the plant's iconic fascination, surprisingly little anatomical detail is known about the genus beyond its modified leaf tip traps. Here, the wood anatomical diversity of Nepenthes is explored. This diversity is further assessed with a phylogenetic framework to investigate whether the wood characters within the genus are relevant from an evolutionary or ecological perspective, or rather depend on differences in developmental stages, growth habits, substrates or precipitation. Observations were performed using light microscopy and scanning electron microscopy. Ancestral states of selected wood and pith characters were reconstructed using an existing molecular phylogeny for Nepenthes and a broader Caryophyllales framework. Pairwise comparisons were assessed for possible relationships between wood anatomy and developmental stages, growth habits, substrates and ecology. Wood anatomy of Nepenthes is diffuse porous, with mainly solitary vessels showing simple, bordered perforation plates and alternate intervessel pits, fibres with distinctly bordered pits (occasionally septate), apotracheal axial parenchyma and co-occurring uni- and multiseriate rays often including silica bodies. Precipitation and growth habit (stem length) are linked with vessel density and multiseriate ray height, while soil type correlates with vessel diameter, vessel element length and maximum ray width. For Caryophyllales as a whole, silica grains, successive cambia and bordered perforation plates are the result of convergent evolution. Peculiar helical sculpturing patterns within various cell types occur uniquely within the insectivorous clade of non-core Caryophyllales. The wood anatomical variation in Nepenthes displays variation for some characters dependent on soil type, precipitation and stem length, but is largely conservative. The helical-banded fibre-sclereids that mainly occur idioblastically in pith and cortex are synapomorphic for Nepenthes , while other typical Nepenthes characters evolved convergently in different Caryophyllales lineages.

Vessel element and fiber length variation in successive cambia of Iresine latifolia (Amaranthaceae)

The size of the axial cell elements of wood, vessel elements and fibers, increases or decreases from pith to stem periphery in the species that have been studied with successive cambium such as members of the Menispermaceae. Iresine latifolia (Amaranthaceae) was selected for this study because it is a scandent shrub widely distributed in Mexico with successive cambia. The objectives were to quantify vessel element and fiber lengths in each of the vascular rings, to evaluate whether cellular size increases or decreases from pith to periphery, and to describe its wood. Macerations were performed for each of the secondary xylem rings present in 3 individual samples, and permanent slides were prepared using conventional procedures for wood. Observations showed that I. latifolia has 13–36 concentric rings, each ring showing an active cambium. Like other species of Amaranthaceae, there are nucleated fibers and multiseriate rays with a meristematic center. Variance analyses showed significant differences between vessel element and fiber lengths between only some of the vascular rings from pith to periphery. These results suggest that the parenchyma cells, from which the new cambium is derived, reach the size of the fusiform initial cells early in the differentiation process.

Internal cambium and intraxylary phloem development in Ipomoea turbinata Lag. (Convolvulaceae)

Strands of phloem that are present at the periphery of pith are known as intraxylary phloem. Its presence remains restricted to a small portion of eudicots and considered as a characteristic feature for certain families. In the present study, Ipomoea turbinata Lag. showed development of intraxylary protophloem on adaxial tips of protoxylem from the procambial derivatives. Subsequently, additional intraxylary sieve elements were added from the adjacent parenchyma cells that were morphologically different from the pith cells. In thick stems, thin walled cells located between protoxylem and intraxylary protophloem acquired meristematic characters and formed several small segments of internal cambium. Initially, these cambial segments produced only phloem derivatives. Soon after, these segments became bidirectional and began to produce secondary xylem centrifugally and secondary phloem centripetally. Interestingly, in some of the samples development of secondary phloem and xylem was observed in the same direction. The secondary xylem formed by the internal cambium was composed of wide and fibriform vessels, fibres and axial parenchyma. Phloem possessed sieve tube elements, companion cells and parenchyma cells while rays in both xylem and phloem were mostly uniseriate but multiseriate rays were also observed.

Estudio anatómico de la madera de cinco especies del genero Quercus (Fagaceae) del estado de Veracruz

Se presenta la descripción macroscópica y microscópica de la madera de cinco especies de encino; dos de ellas, Quercus glabrescens Benth. y Q. potosina Trel., pertenecientes al subgénero Leucobalanus (encinos blancos) y las otras tres, Q. eduardii Trel., Q. ghiesbreghtii M. Martens & Galeotti y Q. xalapensis Humb. & Bonpl., pertenecientes al subgénero Erythrobalanus (encinos rojos), con base en material recolectado en el municipio de Huayacocotla, Veracruz. Se observaron diferencias en el color de la madera, en el tipo de porosidad, en el tamaño de los radios multiseriados y en el tipo y la abundancia de extractivos.

Determinación de algunas propiedades físicas y mecánicas de Grevillea robusta A. Cunn. del estado de Veracruz

Se determinaron las propiedades físicas y mecánicas de la especie Grevillea robusta A. Cunn. con especímenes colectados en la región central del estado de Veracruz. Las propiedades mecánicas se estimaron en condición “verde” y seca. Se determinó que hay un valor alto de la relación entre la contracción tangencial y la radial, lo que generalmente se interpreta como una baja estabilidad dimensional; sin embargo, del secado del material para pruebas mecánicas en condición seca, se obtuvieron piezas con distorsiones pequeñas. Las propiedades mecánicas que se estudiaron fueron flexión estática, compresión paralela y perpendicular a la fibra, dureza, cortante paralelo a la fibra y tenacidad por impacto. Los resultados que se presentan son los valores promedio de cada propiedad, el número de ensayos realizados para obtenerlos, la desviación estándar y el coeficiente de variación, tanto en condición seca como en condición “verde”. Considerando la presencia abundante de radios multiseriados apreciables a simple vista, se estimó el porcentaje del área de una sección tangencial ocupada por dichos radios, encontrando valores altos de este porcentaje que, posiblemente, influyen en la resistencia mecánica de la madera de esta especie. Se encontró que esta madera tiene una resistencia mecánica de baja a media.

Influencia de los radios en algunas propiedades físicas y mecánicas de la madera de ocho encinos (Quercus) de Durango, México

Se presenta la relación del parénquima radial (radios uniseriados y multiseriados) con la contracción volumétrica y las propiedades mecánicas de flexión, compresión paralela y perpendicular y el cortante paralelo de la madera de ocho especies de encinos de Durango, México. Para determinar la relación de los radios con las propiedades tecnológicas, se hizo un análisis de regresión multivariado en 3 donde las variables dependientes fueron los valores anatómicos y las independientes los valores físicos y mecánicos. Los resultados muestran que la altura y anchura de los radios multiseriados son los caracteres anatómicos de mayor influencia en las propiedades tecnológicas. Se resalta que en la selección de la madera de encino para su aprovechamiento, se deben considerar las características anatómicas, físicas y mecánicas, que influyen en su manejo para aprovechar de manera óptima este recurso y lograr la conservación de los encinares y preservar el equilibrio ecológico de los sitios donde crecen.

Anatomía de la madera de las especies arbóreas de Ipomoea (Convolvulaceae)

Se describe la anatomía de la madera de ocho especies de la serie Arborescentes del género Ipomoea, grupo con porte arbóreo o de enredadera leñosa y flores de color blanco o amarillo. Las especies presentan cambia sucesivos que forman anillos concéntricos de xilema, floema y tejido conjuntivo. Todos los taxa tienen vasos solitarios a frecuentemente agrupados, redondeados a elípticos y con diámetro tangencial medio; los elementos de vaso son cortos, con la placa de perforación simple y las punteaduras alternas y poligonales. Presentan tílides. Las fibrotraqueidas van de muy cortas a medianas en su mayoría con un diámetro medio y paredes muy delgadas. El parénquima axial es de tipo vasicéntrico y ocasionalmente en bandas angostas. El parénquima radial está formado por radios uniseriados y multiseriados, heterogéneos, con granos de almidón y drusas. Los resultados coinciden con lo publicado para el grupo, pero se presentan diferencias estadísticas en la longitud y el diámetro medio de las fibras, en la altura y el número de células de los radios uniseriados y en la altura y número de series de los radios multiseriados.

Development of successive cambia and wood structure in stem of Rivea hypocriteriformis (Convolvulaceae)

Abstract This study examined the formation of successive rings of cambia in Rivea hypocriteriformis Choisy (Convolvulaceae). The mature stem is composed of four to five rings of xylem alternating with phloem. Successive cambia originate as smaller and larger segments; union and anastomosing of small cambial segments often leads to the formation of discontinuous rings. In the initial stage of growth, several vascular bundles interconnect to form the first ring of vascular cambium. The cambium remains functional for one complete season and becomes dormant during summer; a new ring of cambium is completed prior to the subsequent monsoon season and sprouting of new leaves. Successive cambia are initiated from the pericyclic parenchyma situated three to four cell layers outside of the protophloem. Functionally, all the successive cambia are bidirectional and produce secondary xylem centripetally and phloem centrifugally. The secondary xylem is diffuse-porous, with indistinct growth rings and consisting of wide fibriform vessels, fibre tracheids, and axial and ray parenchyma cells. The xylem rays are uni- to multiseriate and heterocellular. The multiseriate rays contain lignified marginal ray cells and thin-walled, unlignified central cells. The central ray cells also show accumulations of starch and druses. Discrete strands of intraxylary phloem occur at the periphery of the pith, and additional intraxylary phloem develops from adjacent cells as secondary growth progresses. Earlier-formed phloem shows heavy accumulation of callose, followed by its compaction. The development of successive cambia is correlated with extension growth and with the phenology of the plant.

Gene dosage effects and signatures of purifying selection in lateral organ boundaries domain (LBD) genes LBD1 and LBD18

Wood formation is an economically and environmentally important process and has played a significant role in the evolution of terrestrial plants. Despite its significance, the molecular underpinnings of the process are still poorly understood. We have previously shown that four lateral organ boundaries (LBD) transcription factors have important roles in the regulation of secondary (woody) growth with two (LBD1 and LBD4) involved in secondary phloem and ray cell development and two (LBD15 and LBD18) in secondary xylem formation. We studied gene copy number and variation in DNA and amino acid sequences of the four LBDs in a wide range of woody and herbaceous plant taxa with fully sequenced and annotated genomes. LBD1 showed the highest gene copy number across species, and gene copy number was strongly and significantly correlated with tangential ray width. The climbing vines, cucumber and grape, with wide multiseriate rays (>10 cells wide) showed the highest gene copy number. Because the growth habit of woody lianas like grape requires significant twisting and bending, it was suggested that the unlignified ray parenchyma cells likely facilitate stem flexibility and maintenance of xylem conductivity. We further demonstrate conservation of amino acids in LBD18 protein sequences specific to woody taxa downstream of the LBD domain. Neutrality tests showed evidence for strong purifying selection on these regions across various orders, indicating important functional roles in woody taxa. Additionally, structural modeling demonstrates that these regions have a significant impact on tertiary protein structure and thus are likely of significant functional importance.

Fossil wood from the upper Miocene Mpesida Beds at Cheparain (Baringo District, Kenya): Botanical affinities and palaeoenvironmental implications

Seven wood samples from a petrified forest, in situ in ash flow deposits at Cheparain in the Tugen Hills (Kenya) in the Mpesida Beds, were discovered and studied. The age of the Mpesida Formation is estimated to be about 6.3 Ma on the basis of radio-isotope age determinations on the volcanic deposits, which overlie and underlie the sedimentary levels. The wood samples are mineralized with obvious sectors of differential mineralization, and different degrees of silica impregnation. All samples show heteroxylous structures corresponding to angiosperm dicotyledon trees.One sample consists in a half cylinder showing a well preserved mineralized structure of heteroxylous wood and probably corresponds to a fragment of root. This wood, with solitary (or in radial group) vessels, heterocellular multiseriate rays, paratracheal parenchyma in wide bands, and partly storied fusiform cells, clearly shows affinities with the genus Erythrina (Fabaceae). A slightly compressed branch, partly disturbed by injuries and highly mineralized shows solitary (or in short radial group) vessels, the rays uni-(bi) seriate are heterocellular, and the apotracheal parenchyma is in thin tangential bands. The closest affinities are with the genus Spirostachys (Euphorbiaceae).The other structures are poorly preserved (highly mineralized) and precise botanical affinities cannot be accessed. But the growth rings are distinct or diversely marked and the samples show semi-ring porous structures. They exhibit two different patterns.The growth rings reveal the presence of seasonal climate, and numerous injuries, a disturbance of the vegetation by animals and/or strong climatic events. Erythrina and Spirostachys are present in the extant vegetation of the Tana River Valley, in Kenya, which could represent a modern analogue for the vegetation of the Mpesida Beds prior to the major uplift of the Tugen Hills at the end of the Miocene.

ANATOMIA DO LENHO DE RAIZ, TRONCO E GALHO DE BARBATIMÃO (Stryphnodendron adstringens (Mart) Coville)

Objetivou-se analisar o lenho de raiz, tronco e galho de barbatimão, Stryphnodendron adstringens em área de cerrado, no município de Lavras, MG. Amostras de lenho do tronco e do galho foram retiradas a 0, 25, 50, 75 e 100% da altura total do tronco e comprimento total do galho. Amostras de lenho das raízes foram retiradas a 40 cm de profundidade do solo. Qualitativamente o lenho do barbatimão possui camadas de crescimento distintas para o tronco e galho; na raiz, encontram-se pouco definidas. Porosidade difusa. Placas de perfuração simples. Pontoações intervasculares e raio-vasculares, areoladas, alternas e com guarnições. Parênquima paratraqueal vasicêntrico. Raios predominantemente unisseriados, apresentando raios multisseriados. Os raios são heterocelulares, onde o corpo do raio é formado por células procumbentes e margens com células quadradas e eretas. Observaram-se, raios homogêneos formados apenas por células procumbentes. Presença de cristais nas células dos parênquimas axiais, radiais e nas fibras. Quantitativamente, as características relevantes para o lenho foram: maior frequência de vasos para o galho; paredes das fibras mais espessas no lenho de raiz e raio mais largo no tronco.

Age trends in the wood anatomy of Quercus faginea

The wood anatomy of Quercus faginea, an oak native to the Iberian Peninsula and the Maghreb in Africa, is described and age trends of fibres and ray dimensions are recorded. The analysis was made on a total of 20 trees from two different sites in Portugal. The wood structure within both sites was similar. Quercus faginea shares its microscopic characteristics with other species of the white oak group; i.e., it was not easily distinguishable from other European oaks. The wood is ring porous with wide multiseriate rays and a high proportion of fibres and vasicentric tracheids. There was an increase of fibre and ray dimensions from the pith outwards. Fibre length started to stabilize around 30 years of age up to 50–60 years and decreased afterwards under a traditional rotation period (100–150 years). Linear and polynomial adjustments fitted better the fibre variation at younger and older ages, respectively. Rays were quite homogeneous within the trees. Cambial age accounted less to total variation than individual trees at both sites; i.e., tree-to-tree variation is greater than variation related to maturation or cambial age. The average dimensions of fibres and rays were similar between sites.

Development of Successive Cambia and Structure of Secondary Xylem of Ipomoea Obscura (Convolvulaceae)

Abstract Stems of Ipomoea obscura Ker Gawl., increase in thickness by forming multiple rings of cambia. Stems 5-6 mm thick produce parenchymatous derivatives which divide repeatedly to form small arcs of cambium. Several such small arcs initiate simultaneously and form a ring of small cambial arcs. After the formation of a few xylem and phloem elements, all these arcs are interconnected by transdifferentiation of parenchyma cells present between the cambial arcs and constitute a complete cambial cylinder. This newly formed cambium is functionally bidirectional: earlier- formed arcs produce xylem centripetally and phloem centrifugally, while later-formed segments exclusively produce thin-walled parenchyma cells on either side. Young stems are circular in cross section but as stem thickness increases they become oval to elliptic or lobed and dumbbell-shaped. Xylem rays are mostly uni- or biseriate and thin-walled, but multiseriate rays characteristic for a climbing habit are observed occasionally. In thick stems, the marginal ray parenchyma in most of the samples becomes meristematic and develops ray cambia which exclusively produce sieve elements. Similarly, parenchyma cells produced from later-formed cambial segments give rise to several irregularly oriented vascular bundles. The secondary xylem is diffuse porous, with indistinct growth rings and is composed of fibriform and wider vessels, fibres, and axial and ray parenchyma cells, while phloem consists of sieve elements, companion cells, and axial and ray parenchyma cells.

Loxopterygium wood in Coayuca de Andrade, Oligocene of Puebla, Mexico

A wood type preserved in Oligocene sediments of Coayuca de Andrade, Puebla, Mexico, is described and compared to Loxopterygium Hook. f. (Anacardiaceae). Among the characters that sustain this assignment are growth rings are marked by 2–3 rows of flattened latewood fibers. The vessel elements are circular to oval, predominantly solitary and radial multiples of 2 and 3. The perforation plates are simple, intervascular pits are alternate, oval and polygonal, with lenticular apertures, some of them are coalescent. Axial parenchyma is paratracheal scanty. Rays correspondent to the heterogeneous Kribs type IIB and one to two radial canals occur in multiseriate rays. These same characteristics are important to distinguish it from the extant species in the genus and support the recognition of a new species, Loxopterygium andradensii Méndez-Cárdenas et al. The presence of this new species in the Cenozoic of Mexico confirms the importance of Anacardiaceae in the flora and vegetation of low latitude North America, reinforcing the idea that some elements of the Neotropical flora were in North America before the Plio-Pleistocene Great Biotic exchange and that at some point it was important for the diversification of some taxa.

Anatomical differences between stem and branch wood of Ficus carica L. subsp. carica

The quantitative anatomical differences between the stem and branch wood of Ficus carica L. subsp. carica (Moraceae) were investigated. In spite of the similarity in the qualitative traits, according to statistical analysis, tangential vessel diameter, radial vessel diameter, vessel frequency, vessel wall thickness, multiseriate ray width, fibre length, fibre diameter, and fibre wall thickness showed statistically significant differences in the stem and branch wood of taxon examined. Fibre length and vessel element length in branch wood is about 16% and 3% shorter respectively. In addition, vessel frequency in the branch wood is about 52% higher. Whilst the number of rays per mm is not different in branch wood and stem wood, ray width is about 18% narrower in branch wood.

Anatomía de anillos de crecimiento de 80 especies arbóreas potenciales para estudios dendrocronológicos en la Selva Central, Perú

The knowledge about the existence of annual tree rings in tropical trees, which was already found at the beginning of the last century, was ignored by many scientists for a long time. Wood samples of 80 tree species from seven different sites belonging to Satipo and Chanchamayo provinces in Central Forest, Perú. Wood slices were taken at 1.30 m height, following the Peruvian Technical Norms (NTP) 251-008, COPANT norms 30:1-019 and IAWA (1989). Results showed that 24 of the 80 tree species analyzed showed a potential for dendrocronological studies, 25 had problems for growth-rings analysis, and 31 did not have potential. The problems most frequently found were: barely visible or irregular ring growth, parenchyma bands and multiseriate rays difficult to be identified in rings growth. The "T" Student test showed that the significant variation in vessel and fiber diameters between growth zones (Early-wood and late-wood) of species with potential for dendrocronology, do have a periodic cells production, so is possible to suggest the annual formation of each growth-ring. However, those species without potential to dendrocronology may be influenced by of a lot of factors, such as biotic and abiotic conditions of environment, as well as the genetic aspect of each species.

Wood anatomy of tribe Detarieae and comparison with tribe Caesalpinieae (Leguminosae, Caesalpinioideae) in Venezuela

We studied the wood anatomy of 29 species belonging to 10 genera of the tribe Detarieae, subfamily Caesalpinioideae and compare them with tribe Caesalpinieae. Detarieae is the largest of four tribes of Caesalpinioideae, with 84 genera, only eleven occur in Venezuela with species of timber importance. The specimens were collected in Venezuela and include wood samples from the collection of the Laboratorio de Anatomía de Maderas de la Facultad de Ciencias Forestales y Ambientales de la Universidad de Los Andes, Venezuela, and of the Forest Products Laboratory of the USDA Forest Service in Madison, Wisconsin, USA. The terminology and methodology used followed the IAWA List of Microscopic Features for Hardwood Identification of the IAWA Committee, 1989. Measurements from each specimen were averaged (vessel diameters, vessel element lengths, intervessels pit size, fibre lengths and ray height). The species of Detarieae can be separated using a combination of diagnostic features. Wood characters that provide the most important diagnosis and may be used in systematics of Detarieae include: intercellular axial canals, rays heterocellular, rays exclusively or predominantly uniseriate, prismatic crystals common in ray cells, irregular storied structure and fibre wall thickness. For comparative anatomy between Detarieae and Caesalpinieae: intercellular axial canals, heterocellular rays, rays exclusively or predominantly uniseriate, prismatic crystals common in ray cells (in Detarieae) and regular storied structure, fibres septate, fibre wall thick or very thick, rays homocellular, multiseriate rays and silica bodies (in Caesalpinieae). Axial parenchyma is typically a good diagnostic feature for Leguminosae, but not for Detarieae and Caesalpinieae comparisons.