Extensions of the kidney tubules into the cortical substance.
Strands of parenchymal tissue extending from the pith to the bark and separating the vascular bundles in the stems of certain plants (dicotyledons and gymnosperms)
Medullary-ray Sentence Examples
Such a cell-plate is called a medullary ray.
The xylem and phloem parenchyma consist of living cells, fundamentally similar in most respects to the medullary ray cells, which sometimes replace them altogether.
The cortical tissues gradually shrink and dry up, turning brown and black in patches or all over, and when at length the cambium and medullary ray tissues dry up the whole twig dies off.
The secondary phloem contains numerous thick-walled fibres, parenchymatous cells, and large sieve-tubes with plates on the radial walls; swollen parenchymatous cells containing crystals are commonly met with in the cortex, pith and medullary-ray tissues.
The xylem parenchyma cells are connected, as are the medullary ray cells, with the tracheal elements by one-sided bordered pitsi.e.