Lycopus virginicus

Native

Wet or moist. Marshes, wet meadows, fens, stream banks, ditches, lake shores.

July to September

White

4″ to 40″

This is a 4″ to 40″ tall, erect, perennial forb that rises from a long, horizontal rhizome and fibrous roots. The rhizome does not have tubers. It produces an above-ground runner (stolon) that usually does not have a tuber at the tip.

The stems are erect, branched or unbranched, green, square, hollow, and densely hairy with appressed hairs. They are weak and may sprawl without nearby supportive vegetation. There is a single vertical groove on each side of the stem.

The leaves are opposite and lance-shaped or oval. Each pair of opposite leaves is at right angles to the leaf pairs above and below it. The leaf blades are 2″ to 4¾″ long, and ⅝″ to 1″ wide. They taper at the tip to a point with concave sides along the tip, and taper gradually to the leaf stalk, with concave sides approaching the stalk. The lower leaves are short-stalked and toothed, never lobed. They become progressively shorter stalked as they ascend the stem. Upper leaves are stalkless. The upper surface is hairy with long hairs. The lower surface is hairy with short, felty hairs. The margins are coarsely toothed from just below the middle to the tip. Below that point the margin is untoothed. Although this is a mint, when crushed the leaves do not smell of mint.

The inflorescence is a tight cluster of stalkless flowers in the leaf axils on the upper ⅔ of the stem. Pairs of clusters in opposite leaf axils form false whorls.

The green sepals (calyx) are united for most of their length into a 1 ⁄16″ to ⅛″ long, bell-shaped tube with 4 teeth. The calyx teeth are egg-shaped or triangular. There are 5 white petals (corolla) that are united at the base into a tube that is barely longer than the calyx tube, and are separated at the tip into 4 spreading lobes. The upper lobe is notched at the tip and is broader than the lower and lateral lobes. There are 2 fertile stamens with brown anthers and 2 sterile stamens (staminodes). The stamens are shorter than or barely as long as the corolla tube. The staminodes are club-like and are shorter than the corolla tube. The flowers are not fragrant.

The fruit is a set of 4 egg-shaped, brown, hairless, ridged nutlets with one seed each. The inner angle is as long as the outer ones so that the center of the nutlets is almost flat across. When the fruit is mature the nutlets surpass the calyx lobes.

See the Lycopus ID Filter for a spreadsheet to aid identification of this and similar species.

American bugleweed (Lycopus americanus) leaves have deep, coarse, irregular teeth. The lower leaves are pinnately lobed near the base. The upper leaf surface is hairless. The lower surface is hairless except for short hairs along the veins. The calyx has 5 narrow, sharply pointed teeth that are more than twice as long as their base is wide. When the fruit is mature the calyx lobes surpass the nutlets. The cluster of 4 nutlets is depressed across the top, not flat.

Northern bugleweed (Lycopus uniflorus var. uniflorus) produces a stolon with a tuber at the tip. The leaves are much shorter. The base of the leaves are wedge-shaped with straight or slightly convex, never concave, sides. The upper and lower surfaces are hairless or nearly hairless. The margins toothed, including near the base. The calyx has 5 teeth, not 4. The stamens are conspicuously longer than corolla tube. The corolla has 5 lobes, not 4. The stamens are longer than the corolla tube. The cluster of 4 nutlets is depressed across the top, not flat.

Rough bugleweed (Lycopus asper) leaves are a little wider, broad at the base, and stalkless. The underside is hairless or minutely hairy. The margins toothed, including near the base. The calyx has 5 teeth, not 4. The calyx teeth are longer, 1 ⁄16″ to ⅛″ long. When the fruit is mature the calyx lobes surpass the nutlets. The cluster of 4 nutlets is depressed across the top, not flat.

Sherard’s waterhorehound (Lycopus X sherardii) is a hybrid between this species and northern bugleweed. It is found wherever the ranges of the two species overlap.