Dead nettle, a common sight in lawns and gardens, is often mistaken for a stinging weed. This widespread plant belongs to the Lamium genus and is a member of the mint family, Lamiaceae. Dead nettle is frequently found in disturbed soils, along roadsides, and in fields, with the most common species being Purple Dead Nettle (Lamium purpureum). Correctly identifying this plant relies on recognizing its unique vegetative features, flower structure, and the absence of irritating hairs.
The Defining Features of the Foliage
A primary identification mark of dead nettle, shared by all members of the mint family, is its distinctively square stem. If you gently roll the stem between your fingers, you can easily feel the four flat sides, a characteristic that helps distinguish it from many other plants. The leaves grow in opposite pairs along this square stem, with each subsequent pair rotated 90 degrees from the one below it.
The leaves are typically heart-shaped or broadly triangular and feature serrated or toothed edges. They are covered in fine, soft hairs that give them a textured, downy feel. A clear visual cue, particularly in the Purple Dead Nettle variety, is the striking purple or reddish tint that colors the leaves nearest to the top of the plant. These upper leaves often appear crowded or overlapping, contrasting with the greener leaves found lower down the stem.
Flower Structure and Coloration
Dead nettle flowers form small, elongated tubes that emerge in dense clusters, or whorls, around the stem. These whorls appear where the upper leaves meet the main stalk, known as the leaf axils. Each individual flower is small and possesses a two-lipped corolla, giving it a hooded or trumpet-like shape.
The coloration of the flowers can vary depending on the specific Lamium species, ranging from white in White Dead Nettle (Lamium album) to pink, lavender, or a reddish-purple in Purple Dead Nettle. These colorful blooms often appear early in the spring, sometimes even during mild winter weather. The flowers are a significant source of nectar, particularly attractive to long-tongued insects like bumblebees.
Key Differences from Stinging Nettle
The name “dead nettle” refers to its primary distinguishing feature from the true Stinging Nettle (Urtica dioica): the complete absence of stinging hairs. Stinging Nettle is covered in fine, hollow, needle-like hairs called trichomes that inject irritating chemicals upon contact, causing a painful rash. Dead Nettle, conversely, has soft, non-stinging hairs, making it safe to handle.
The two plants have different stem shapes; Dead Nettle has a square stem, while Stinging Nettle features a rounder, often ridged or furrowed stem. Stinging Nettle produces tiny, inconspicuous, greenish-white flowers that droop in clusters, unlike the hooded and upright flowers of dead nettle. While both plants have opposite leaves, Stinging Nettle leaves are typically more elongated and pointed, and the plant often grows much taller, whereas dead nettle is a low-growing plant.