pith ray

American  

noun

1. medullary ray.

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Etymology

Origin of pith ray

First recorded in 1900–05

Example Sentences

P, pith; PB, primary bast; SB, secondary bast; C, cambium; PR, pith ray; PW, primary wood; SW, secondary wood; PS, procambium strands.

From Project Gutenberg

Isolated Fibers and Cells. a, four cells of wood parenchyma; b, two cells from a pith ray; c, a single cell or joint of a vessel, the openings, x, x, leading into its upper and lower neighbors; d, tracheid; e, wood fiber proper.

From Project Gutenberg

Microscopically the white pine can be distinguished by having usually only one large pit, while spruce shows three to five very small pits in the parenchyma cells of the pith ray communicating with the tracheid.

From Project Gutenberg

The following convenient and useful classification of pines into four groups, proposed by Dr. H. Mayr, is based on the appearance of the pith ray as seen in a radial section of the spring wood of any ring: Section I. Walls of the tracheids of the pith ray with dentate projections. a.

From Project Gutenberg

Walls of tracheids of pith ray smooth, without dentate projections. a.

From Project Gutenberg