Lamium amplexicaule, commonly known as henbit dead-nettle, is a species of Lamium native to most of Europe, Asia and northern Africa. The specific name refers to the leaves, which are amplexicaul (clasping the stem).
It is a low-growing annual plant growing to 10–25 cm (4–10 in) (rarely to 40 cm) tall, thinly pubescent with soft, finely hairy stems. The leaves are opposite, rounded to kidney-shaped, 2–3 cm (3⁄4–1+1⁄4 in) diameter, with a lobed margin, and often with long internodes. The lower leaves are stalked and the upper ones stalkless, often fused, and clasping the stems. The flowers are pink to purple, relatively large, 1.5–2 cm (1⁄2–3⁄4 in) long, and form a few-flowered terminal spike with axillary whorls. The calyx is regular with five lobes and closes up after flowering. The corolla is purplish-red, fused into a usually erect tube 15 to 20 mm (1⁄2 to 3⁄4 in) long. The upper lip is convex, 3 to 5 mm (1⁄8 to 3⁄16 in) long and the lower lip has three lobes, two small side ones and a larger central one 1.5 to 2.5 mm (1⁄16 to 1⁄8 in) long. There are four stamens, two long and two short. The gynoecium has two fused carpels and the fruit is a four-chambered schizocarp.
This plant flowers very early in the spring even in northern areas, and for most of the winter and early spring in warmer locations such as the Mediterranean region. At times of year when there are not many pollinating insects, the flowers self-pollinate.
