Medullary Ray

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medullary ray

[me′dəl·ə·rē ‚rā]
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.
Portland, OR, said he thinks the took is only because of the large medullary rays.
White oak has a beautiful tan color, it is water resistant, it steam bends beautifully and when quarter sawn, and it has a wonderful pattern with the flake of the medullary rays.
You get a flake look because of the medullary rays of the wood that is very attractive.