aril

The fleshy scarlet covering formed around the naked seed in the yew is by some considered of the nature of an aril.

From Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 3 "Frost" to "Fyzabad" by Various

But on closer inspection we observe that the flower stalks are combined into little groups, each group occupying the aril of one of the basal leaves.

From Species and Varieties, Their Origin by Mutation by Vries, Hugo de

Fruit about size of child’s head or smaller, somewhat pear-shaped, juicy, pulp melon-like, 1 compartment with numerous seeds, each in a mucilaginous aril.

From The Medicinal Plants of the Philippines by Thomas, Jerome Beers

The aril which surrounds the seed and the roots of Sapindus Saponaria, an evergreen tree, I have seen used as soap in South America and the West Indies under the name of soap berries.

From The Commercial Products of the Vegetable Kingdom Considered in Their Various Uses to Man and in Their Relation to the Arts and Manufactures; Forming a Practical Treatise & Handbook of Reference for the Colonist, Manufacturer, Merchant, and Consumer, on the Cultivation, Preparation for Shipment, and Commercial Value, &c. of the Various Substances Obtained From Trees and Plants, Entering into the Husbandry of Tropical and Sub-tropical Regions, &c. by Simmonds, P. L.

The fruit is about the size of an ordinary walnut, with a thick rind, which, upon opening, at maturity, discloses a reddish aril covering the nut within.

From The Nut Culturist A Treatise on Propogation, Planting, and Cultivation of Nut Bearing Trees and Shrubs Adapted to the Climate of the United States by Fuller, Andrew S.