§ 1. Flowers loose, without long-subulate bracts; calyx villous in the throat.
[*] Pubescent; peduncles short but mostly distinct; bracts minute.
C. Népeta, Link. (Basil-Thyme.) Soft-hairy; stem ascending (1–3° high); leaves petioled, broadly ovate, obtuse, crenate; corolla (3´´ long) twice the length of the calyx.—Dry waste grounds, Md. to Ark. (Nat. from Eu.)
[*][*] Glabrous or nearly so; common peduncles hardly any; pedicels 1–5, slender, the conspicuous bracts subulate-acuminate; on wet limestone river-banks.
1. C. glabélla, Benth. Smooth; stems diffuse or spreading (1–2° long); leaves slightly petioled, oblong or oblong-linear, narrowed at base (8´´–2´ long), sparingly toothed or nearly entire; clusters 3–5-flowered; corolla (purplish, 5–6´´ long) fully twice the length of the calyx.—S. Ind., Ky., and Tenn.
2. C. Nuttàllii, Gray. Smaller; the flowering stems more upright (5–9´ high), with narrower mostly entire leaves and fewer-flowered clusters, while sterile runners from the base bear ovate thickish leaves only 2–5´´ long. (C. glabella, var. Nuttallii, Gray.)—Niagara Falls to Minn., south to Mo. and Tex.
§ 2. Flowers in sessile dense many-flowered clusters, and involucrate with conspicuous setaceous-subulate rigid bracts; calyx nearly naked in the throat.
3. C. Clinopòdium, Benth. (Basil.) Hairy, erect (1–2° high); leaves ovate, petioled, nearly entire; flowers (pale purple) in globular clusters; hairy bracts as long as the calyx.—Borders of thickets and fields, naturalized extensively, but indigenous from the Great Lakes to the Rocky Mts. (Eu., Asia)
16. MELÍSSA, L. Balm.
Calyx with the upper lip flattened and 3-toothed, the lower 2-cleft. Corolla with a recurved-ascending tube. Stamens 4, curved and conniving under the upper lip. Otherwise nearly as Calamintha.—Clusters few-flowered, loose, one-sided, with few and mostly ovate bracts resembling the leaves. (Name from μέλισσα, a bee; the flowers yielding abundance of honey.)