Comparative Wood Anatomy in Pinaceae with Reference to Its Systematic Position

The wood anatomy of 132 species of the genera Abies, Cathaya, Cedrus, Keteleeria, Larix, Nothotsuga, Picea, Pinus, Pseudolarix, Pseudotsuga and Tsuga was studied to determine the elements that characterise the xylem of each genus and discuss possible groupings by wood anatomy for comparison with clades established by molecular phylogeny. The presence of resin canals and ray tracheids supports the family Pinaceae, although the absence of ray tracheids in Keteleeria and their occasional presence in Abies and Pseudolarix weakens it. Based on wood structure, Pinaceae clearly supports division into two groups, coinciding with molecular phylogeny: Pinoideae (Cathaya-Larix-Picea-Pinus-Pseudotsuga) and Abietoideae (Abies-Cedrus-Keteleeria-Nothotsuga-Pseudolarix-Tsuga). Although differences between genera are slight in Pinoideae, the Abietoideae group presents problems such as the presence of only axial resin canals in Keteleeria and Nothotsuga, absence of ray tracheids in Keteleeria and presence of traumatic radial resin canals in Cedrus. However, other features such as pitted horizontal walls and nodular end walls of ray parenchyma cells, indentures, scarce marginal axial parenchyma and presence of crystals in ray parenchyma strengthen the Abietoideae group.

Comparative wood anatomy of Atraphaxis taxa in Turkey

The wood anatomy of four Atraphaxis taxa that have natural distribution in Turkey—Atraphaxis billardieri Jaub. & Spach, Atraphaxis billardieri subsp. tournefortii (Jaup. & Spach) Lovelius, Atraphaxis spinosa L., and endemic Atraphaxis grandiflora (Willd.)—were compared in this study. The wood samples were sectioned according to standard techniques. Samples were macerated with Schultze’s method. Tangential and radial vessel diameters, intervessel pit diameters, vessel wall thickness, vessel elements length, dimensions of libriform fibres (lengths, widths, cell wall thickness and, lumen diameter), and uniseriate and biseriate ray heights were measured, and the number of vessels per mm2, number of rays per mm, and number of vessels per group were counted. The qualitative features such as growth rings, vessel grouping, presence of helical thickening and storied structure, vestured pits, type of perforation plate, and arrangement of axial parenchyma were determined. These four species of Atraphaxis shrubs differ in some wood characteristics such as growth rings, vessel grouping, vestured pits, height and density of rays, number of vessels per mm2, and the dimensions of the vessel.

Comparative wood anatomy of Astropanax and Neocussonia, an Afro-Malagasy lineage of Araliaceae

Astropanax and Neocussonia are two recently resurrected genera of Araliaceae that had long been considered as an Afro-Malagasy lineage of Schefflera. The wood structure of 11 Neocussonia spp. and eight Astropanax spp. has been studied. Neocussonia shows a higher average length of vessel elements (1319 µm) and number of bars on perforation plates (up to 66) than any other Araliaceae examined to date. Neocussonia is distinct from Astropanax by its smaller diameter and higher frequency of vessels, rare occurrence of simple perforation plates, more numerous bars on scalariform perforation plates and smaller intervessel pits. The interspecific variation in percentage of simple perforation plates, bar number on scalariform perforation plates, vessel frequency and uniseriate ray number is affected by seasonality in temperature and precipitation. The sharp distinction in wood structure between samples of A. abyssinicus from Cameroon and Burundi suggests that the populations from different parts of the disjunct range represent two different species. Our data also suggest that A. goetzenii is an artificial group. Astropanax myrianthus from Madagascar and A. polysciadus from continental Africa, two cryptic species that have long been included in Schefflera myriantha, show significant differences in vessel size and grouping, percentage of simple perforation plates and intervessel pit size.

Comparative wood anatomy of Korean Viburnum L. (Adoxaceae) and its taxonomic implication

Comparative wood anatomy of Viburnum was carried out to understand the differences in wood features amongst the species which might be useful for taxonomic discrimination in the genus. Altogether, nine taxa belonging to five clades were investigated using a sliding microtome and light microscopy. The growth rings are well represented and earlywood and latewood are distinguishable in cross-section. Some of the important wood features include angular, oval and rounded vessels with scalariform perforation plates, opposite to scalariform inter-vessel pitting, rounded pits with slit-like apertures, thick-walled xylem tracheids with simple, rounded bordered pits, diffuse axial parenchyma, uni- and multiseriate rays, 2–4 cells wide. In general, there is a remarkable uniformity in the qualitative wood features in Viburnum species, although quantitative measurement showed some disparities. The most significant quantitative wood variables which might be useful for taxonomic groupings of the species comprise a frequency of vessels and rays, the diameter of the vessels and tracheids in the radial and tangential planes and height and width of rays in the tangential plane.

Comparative wood anatomy of two tropical species

Wood Anatomy is science field very relevant to understanding environmental climate changes and important in suggested to species conservation. The present study proposed the characterization of wood anatomy of Inga alba and Tapirira guianensis from two locations in the Legal Amazon, establishing ecological relationships between both and their habitat. The species were described and characterized according to standards for wood anatomy of IAWA. The quantitative data were submitted to ANAVA and later to PCA (principal components analysis). Qualitatively, characters such as slightly different growth layers, bounded by fibrous zones, diffuse porosity, diagonal arrangement, predominantly solitary vessel, simple perforate plate, libriform and septate fibers, heterogeneous rays were common the two species independent sites following the pattern for Tropical rainforests. However, there were quantitative differences for diameter and frequency mm2 of vessel, and frequency of rays per linear mm related in sites where substrates are most nutritious. As for diameter of pits, there were significant differences, however, in this case, related to species. Similarities between qualitative characters suggest that species inserted in the same environment, even if they belong to different rates, can share several adaptive characters.

Comparative wood anatomy of eight tree species of Mimosa sect. Batocaulon (Leguminosae) distributed in Mexico and their taxonomic implications

The great diversity of the genus Mimosa and the difficulty in the circumscription of its species and varieties based on morphology have encouraged the search for characters in other sources of evidence such as wood anatomy, which provides characters of taxonomic importance. The main objective of this study was to identify characters with taxonomic value for Mimosa; we studied the wood anatomy of eight tree species in Mimosa sect. Batocaulon from Mexico: Mimosa acantholoba, M. bahamensis, M. benthamii, M. hexandra, M. leucaenoides, M. tejupilcana, M. tenuiflora, and M. texana belonging to eight series: Acantholobae, Bahamenses, Distachyae, Bimucronatae, Leucaenoideae, Plurijugae, Leiocarpae and Boreales, respectively. One stem fragment (80 cm in length) was collected at 80 cm above soil height, from three plants per species. Twenty-five measurements were taken per individual for 15 anatomical characters. Three species have ring-porous wood and five species have diffuse-porous wood; the species differ in colour, figure, in the prevalence of a certain type of axial parenchyma, in the tangential diameter of the earlywood vessels, in the number of vessels connected by confluent-aliform parenchyma, in the number of series of rays and in the presence or absence of crystal sand in the ray cells. These characters have taxonomic value at species level, but not at series level. At the section level, the presence of homocellular rays distinguished Batocaulon from other sections of the genus. Based on these results, we produced a wood anatomical identification key to the eight studied species.

Comparative wood anatomy of Ficus cestrifolia (Moraceae) in two distinct soil conditions

Wood anatomical traits respond to environmental variables and among them, soil has a direct impact on secondary xylem. This study compares the wood anatomy of two populations of Ficus cestrifolia occurring in two lowland formations of Southern Brazil (MAQ and SJS) with similar climate but different soil conditions. Wood samples were collected at breast height and prepared according to standard wood anatomy techniques. Soil samples were collected and subjected to a nutrient analysis. Wood was described quali and quantitatively. The qualitative wood anatomical features of both populations were similar. Some quantitative differences were observed. In MAQ area, the levels of macro- and micronutrients were higher than in SJS. Its population presented higher vessel frequency, thicker-walled fibers, and lower vulnerability index. SJS's population had longer fibers, wider rays and a higher ray frequency, and higher vulnerability index. This suite of characters indicates that the MAQ population has a safer and more efficient xylem structure for water conduction. Under the influence of similar climate and soil type, differences regarding wood anatomical traits found between the two populations of Ficus cestrifolia can thus be regarded as an ecological response to the micro-environmental soils nutrients composition.