medullary ray

9.9

A band of cells in a stem or root that moves water and nutrients sideways

noun
/ˈmɛdʌlɛri reɪ/

Specialized

: rayo medular

The medullary ray can easily be seen in a cross-section of a woody stem.

Examples

Scientists study the medullary rays to better understand nutrient transport in trees.
In many trees, medullary rays help in the transport of nutrients.
In many plants, the medullary ray divides the vascular bundles and aids in water movement.
The medullary ray plays an important role in plant structure.
In many plants, the medullary ray divides the vascular bundles and aids in water movement.
Scientists study the medullary rays to better understand nutrient transport in trees.
The medullary ray can easily be seen in a cross-section of a woody stem.

Synonyms

vascular ray

vsmedullary ray

Specialized

9.8

A thin layer of cells in a plant stem that moves water and food sideways

consists of parenchyma cells extending from the pith to the cortex rather than vascular tissue

Surface Forms

medullary ray singular

medullary rays plural

Morphology

medullary + ray

The elements 'medullary' (relating to the medulla or central tissue) and 'ray' (a radiating or sheet-like structure) transparently suggest a radial structure arising from central plant tissue, so a B1 learner could infer a general anatomical/structural sense. However, the precise botanical function and specific anatomical details (parenchyma sheets separating vascular bundles and facilitating radial transport) are technical and not fully predictable from the parts alone, so full understanding requires specialist knowledge.

Etymology

Medullary ray comes from a word for soft 'marrow' or inner part (medullary) and a 'ray' or 'spoke' that runs out from the centre (ray). The tissue is a thin sheet that runs from a plant's centre out toward the outer part like a spoke and helps water and nutrients move across the stem, so the name describes what it does today.