ClimateAugust 18, 2026

keystone

KEE-stohn

Definition

A plant or animal species that plays such a critical role in an ecosystem that its presence or absence fundamentally dictates the survival and diversity of other species within that same environment.

Etymology

Derived from the architectural term for the central, wedge-shaped stone at the top of an arch that locks all other stones into place; metaphorically extended in biology to describe a central species that holds an ecosystem together.

In the news

The article uses the term to describe specific trees and shrubs that provide essential ecological support for a wide array of other wildlife, arguing that prioritizing these 'powerhouse' plants is the most efficient way to restore biodiversity.

Column | See which native plants will thrive in your garden

Read the full article ↗

The Washington Post

Related words

Learn a word like this every day

Meet one new word every morning.

Newspoken pulls one carefully chosen word from the day’s news — with a clear definition, context, and light review that makes it stick. Get it on your phone.