Annual-rings Sentence Examples
A few years ago a full-sized tree was felled in Fresno county, California, and contiguous transverse sections have been set up, one in the Museum of Natural History at New York, the other (upper one) in the British Museum of Natural History at South Kensington; the annual rings of the latter section have been carefully counted and found to indicate an age of 1335 years.
Owing to differences in the character of the elements produced at the beginning and end of the season, the wood is marked out in transverse section into concentric rings, one for each season of growth - the so-called annual rings.
The wide annual rings show that the tree was grown too quickly, probably in marshy ground.
The annual rings are well defined, each ring consisting of a hard and a soft portion, respectively dark and light in colour.
The colour of the cut wood is a very light yellowish or brownish white, the hard parts of the annual rings being of a darker shade.Advertisement
The annual rings in a root are often less clearly marked than in the stem, and the xylem-elements are frequently larger and thinner.
In the Araucarian type of wood (Araucaria and Agathis) the bordered pits, which occur in two or three rows on the radial walls of the tracheids, are in mutual contact and polygonal in shape, the pits of the different rows are alternate and not on the same level; in this type of wood the annual rings are often much less distinct than in Cupressus, Pinus and other genera.