Close this search box.

Word of the Week: Aril

Like what you see? Share this post

Welcome to Word of the Week! Stay tuned for a new word each Friday to amp up your nature vocabulary!

Aril [AR-il] (noun): A fleshy and usually brightly colored cover of some seeds that develops from the ovule stalk and partially or entirely envelopes the seed.

Easily recognized for its bright arils is an evergreen tree in the conifer family known as the Yew. Because of their red colour, the arils of a Yew tree are often mistaken for berries, but they are actually a highly modified seed cone scale.

The arils are usually tucked away among the foliage of the tree until the fruit becomes visible, hanging from stems early in the Fall. Each aril has a square opening at the bottom of its flesh that contains a brown cone.

This brown cone as well as most of the other parts of the Yew tree are made up of an extremely toxic compound. Only the fleshy red arils they produce are non-toxic. This toxic compound serves as a self-defense mechanism to help prevent animals from eating the Yew tree. However, there are a few animals that have adapted to the toxin and can consume parts of the tree. Also, the non-toxic red arils are a sweet source of food for many different species of birds.

Keep an eye out for Yew trees and their red arils on your next visit to High Park!