nucellus

American  

[noo-sel-uhs, nyoo-] / nuˈsɛl əs, nyu- /

noun

Botany.

PLURAL

nucelli

1. the central cellular mass of the body of the ovule, containing the embryo sac.

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nucellus British  

/ njuːˈsɛləs /

noun

1. the central part of a plant ovule containing the embryo sac

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nucellus Scientific  

/ no̅o̅-sĕl′əs /

PLURAL

nucelli

1. The megasporangium of a seed-bearing plant, located in the ovule. In angiosperms, it is the central portion of the ovule in which the embryo sac develops. In some cases of apomixis (production of seeds without fertilization), cells of the nucellus develop into an embryo.

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Other Word Forms

• nucellar adjective

Etymology

Origin of nucellus

1880–85; < New Latin, equivalent to Latin nuc- (stem of nux ) nut + -ella -elle

Example Sentences

A papery remnant of nucellus lines the inner face of the woody shell, and, as in cycadean seeds, the apical portion is readily separated as a cap covering the summit of the endosperm.

From Project Gutenberg

The hilum or base of the seed, and the chalaza or base of the nucellus are united by means of the raphe r.

From Project Gutenberg

There are thus two integuments to the nucellus, an outer and an inner.

From Project Gutenberg

The nucellus is a cellular tissue enveloping one large cell, the embryo-sac or macrospore.

From Project Gutenberg

Each ovule is enclosed at the base by an envelope or collar homologous with the lamina of a leaf; the fleshy and hard coats of the nucellus constitute a single integument.

From Project Gutenberg