A wood anatomy key based on reliable xylem features of ray type and proportions separates the six genera in the family Vochysiaceae. Selected anatomical features of 57 species are summarized. The wood anatomical range encountered is presented in descriptions for each genus.Woods of the Vochysiaceae differ from closely related taxa. Vochysiaceae have vestured vessel pitting and only libriform fibers; banded axial parenchyma and traumatic interce11ular canals occur frequently; heartwoods of a11 Vochysiaceae test positive (turn blue) with the application of Chrome-Azurol-S. * Maintained at Madison, Wis., in cooperation with the University ofWisconsin.
A vast source of oak wood is available for use in the United States for papermaking. Knowledge of the proportions of tissue types and cell dimensions for hardwoods, especially on a weight basis, could help extend their use in the pulp and paper industry. This report provides such information for 11 red and white oak species. A method for calculating tissue proportions by weight from proportions by volume is given. The proportion by weight for fibers varied from 74% for fast-grown trees to 38% for slow-grown trees; for axial and ray parenchyma from 24% for fast grown to 54% for slow grown; and for vessels from 2% for fast grown to 8% for slow grown. Results show the relationship of tissue proportions to both growth rate and site. Information in this report can be used to help decide whether it is economical to separate fines and other components in pulping hardwoods. The amount of axial and ray parenchyma by weight in slow-grown material suggests it may be economically feasible to separate the parenchyma for possible use as fuel, chemical stock, or cattle feed.
The woods of 15 genera of the tribe Cassieae and 4 genera of the Cercideae were studied for presence or absence of vestured pits. Vestured pits are absent from the subtribes Dialiinae, Duparquetiinae and Labicheinae and from all Cercideae studied. These results are compared with variation patterns in other wood anatomical features and discussed in terms of tribaI delimitation and affinities between subtribes in this part of the Leguminosae.
Torque is a vector component of wind acting on a growing tree. Mechanical devices which were attached to the tree were used to twist a single internode, which simulated the torque component in the absence of bending.Treatments either in a clockwise or counterclockwise direction were initiated at 20° and increased periodically through the entire growing season. Grain angle changed as much as 250% and radial growth was enhanced by as much as 100%, but fiber length decreased 20%.
Under natural conditions, the tree is stressed statically by the mass of the crown and bole. Pairs of steel rods drilled through two branch whorls were connected by turnbuckles to simulate increasing static load on a given internode. Level of soil moisture was included to discern its influence on the effect of static loading.Compression and moisture stress each reduced radial growth. After computed loading exceeded the proportional limit, the next-formed fibers were greatly expanded radially and, when macerated, exhibited extreme twisting. The fibers produced before the proportional limit was exceeded exhibited compression failures when macerated.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.