Medullary ray (botany)
Medullary rays, also known as vascular rays or pith rays, are cellular structures found in some species of wood. They appear as radial planar structures, perpendicular to the growth rings, which are visible to the naked eye. In a transverse section they appear as radiating lines from the centre of the log. In an axial section they may appear as a variety of transverse markings, depending on how close the section is to the plane of the ray. In a tangential section they may be hard to see at all.[citation needed]
They are formed by the activity of fascicular
These medullary or pith rays are essential for the radial conduction of the water, minerals and other organic substances. They transport the substances from center to periphery.[citation needed]
In this context, the term refers to radial sheets or ribbons extending vertically through the tree across and perpendicular to the growth rings. Also called pith rays or wood rays, these formations of primarily
In
References
- ISBN 0-88029-318-7.