Medullary Ray


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medullary ray

[me′dəl·ə·rē ‚rā]
(botany)
An extension of pith between vascular bundles in the plant stem. Also known as pith ray.

Medullary Ray

 

a single or polystichous layer of parenchymal cells that intersect the lignin and bast of stems and roots of dicotyledonous plants. Medullary rays serve a storage function and transport matter in a horizontal direction.

medullary ray, pith ray

medullary rays
In a cross section of a tree or log, one of the ribbons of tissue extending radially from the pith; may vary from microscopic to 4 in. (10 cm) or more in oak; used to store and transport food horizontally within the tree.
References in periodicals archive ?
The Limousin oak was characterized by the high content of ellagitannins and ellagic acids--no doubt resulting from the high proportion of summer wood and the numerous medullary rays. Limousin oak also contained high levels of hmf, although this compound seems unlikely to influence flavor in itself, in view of its high sensory threshold (Sefton, 1991, Chatonnet, et al.
The rich tones of their furniture are achieved by fuming the wood - a process used in the early 1900s by the Arts and Crafts movement - which as well as colouring the oak, accentuates the medullary rays.
In Australia, silky oak has been used in applications as a substitute for oak, but Miles Gilmer, owner of Gilmer Wood Co., Portland, OR, said he thinks the took is only because of the large medullary rays. "It might resemble the look of quartersawn oak somewhat, but oak has less luster and chatoyance."
Wood has prominent medullary rays. Close, fine, hard, compact, interlocking grain.