Family, Mint. Color, whitish or light purple, dotted with darker purple. Leaves, long, narrow, nearly sessile, clustered thickly in the axils; those nearest the flowers whitish, with a soft down. July and August.
There are several species of mountain mint, found oftener below the hills than upon them. Most of them have small flowers with a 5-toothed calyx and 2-lipped corolla crowded in button-like heads, downy, whorled around the stem and terminal in close cymes. With the heads are short, stiff, pointed bracts. It is not easy always to distinguish the species. (See illustration, p. 343.)
P. flexubsum often grows with the last. Color, purple. Leaves, linear, firm. Calyx-teeth, awn-pointed. Heads of flowers terminating the branches.
Dry ground throughout the Atlantic States.
P. muticum has broader leaves than the last, with rounded or heart-shaped bases, and few, rather large heads of purplish flowers in dense clusters, corymbose. Whole plant downy.
New Hampshire to Missouri and southward.
P. Torreu - Color, purple. Heads of flowers, roundish, terminal, dense. Green throughout, and not, like the last, whitish. Leaves, thin, petioled, long, narrow, pointed at both ends.
Dry soil, fields and woods, New York to Georgia.
P. incanum. - Color, purple. Flowers, in large, open cymes or loose clusters, terminal and in the upper axils. Leaves, ovate, those above covered with whitish down on both sides, with short petioles, broadly toothed.
Open woods and dry hills, Virginia to Georgia. All these species of the mountain mint grow in dry soil, in fields or woods, and are common in the Atlantic States, north and south.