Calyx bell-shaped, 4–5-toothed, naked in the throat. Corolla bell-shaped, scarcely longer than the calyx, nearly equally 4-lobed. Stamens 2, distant; the upper pair either sterile rudiments or wanting. Nutlets with thickened margins.—Perennial low herbs, glabrous or puberulent, resembling Mints, with sharply toothed or pinnatifid leaves, the floral ones similar and much longer than the dense axillary whorls of small mostly white flowers; in summer. (Name compounded of λύκος, a wolf, and ποῦς, foot, from some fancied likeness in the leaves.)
[*] Stoloniferous, the long filiform runners often tuberiferous; leaves only serrate.
[+] Calyx-teeth usually 4, barely acutish, shorter than the mature nutlets.
1. L. Virgínicus, L. (Bugle-weed.) Stem obtusely 4-angled (6´–2° high); leaves oblong or ovate-lanceolate, toothed, entire toward the base, acuminate at both ends, short-petioled; calyx-teeth ovate.—Shady moist places, Lab. to Fla., Mo., and northwestward across the continent.
[+][+] Calyx-teeth usually 5, very acute, longer than the nutlets.
[++] Bracts minute; corolla twice as long as the calyx.
2. L. sessilifòlius, Gray. Stem rather acutely 4-angled; leaves closely sessile, ovate or lanceolate-oblong (1–2´ long), sparsely sharply serrate; calyx-teeth subulate, rigid. (L. Europæus, var. sessilifolius, Gray, Man.)—Pine barrens of N. J. to Cape Cod, Mass. (Deane).
3. L. rubéllus, Moench. Stem rather obtusely 4-angled; leaves petioled, ovate-oblong or oblong-lanceolate, sharply serrate in the middle, attenuate-acuminate at both ends (3´ long); calyx-teeth triangular-subulate, not rigid-pointed. (L. Europæus, var. integrifolius, Gray.)—Penn. to Minn., and southward.
[++][++] Outer bracts conspicuous; corolla hardly exceeding the calyx.
4. L. lùcidus, Turcz., var. Americànus, Gray. Stem strict, stout, 2–3° high; leaves lanceolate and oblong-lanceolate (2–4´ long), acute or acuminate, very sharply and coarsely serrate, sessile or nearly so; calyx-teeth attenuate-subulate.—Sask. and Minn. to Kan., thence west to Calif.