primary root

American  

noun

Botany.

1. the first root produced by a germinating seed, developing from the radicle of the embryo.

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primary root Scientific  

1. The first root of a plant, originating in the embryo. In gymnosperms, eudicotyledons, and magnoliids, the primary root develops into the taproot. In monocotyledons, the primary root disintegrates as the lateral roots develop into a system of fibrous roots.

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Etymology

Origin of primary root

First recorded in 1885–90

Example Sentences

Grain of Indian Corn in germination, the ascending sprout is the first leaf of the plumule, enclosing the younger leaves within, at its base the primary root has broken through.

From The Elements of Botany For Beginners and For Schools by Gray, Asa

These are exactly like the primary root from which they spring; there is no difference in structure or in machinery of growth. 

From Rustic Sounds and Other Studies in Literature and Natural History by Darwin, Francis, Sir

When the primary root grows more rapidly than the secondary roots, the so-called taproot, characteristic of lucerne, clover, and similar plants, is formed.

From Dry-Farming : a System of Agriculture for Countries under a Low Rainfall by Widtsoe, John Andreas

G, a germinating seed, × 2. r, the primary root.

From Elements of Structural and Systematic Botany For High Schools and Elementary College Courses by Campbell, Douglas Houghton

These are all simple, that is, there is but one primary root.

From Outlines of Lessons in Botany, Part I; from Seed to Leaf by Newell, Jane H.