Flower:

Round cluster 1 to 2 inches across of tubular flowers, solitary at the end of branching stems arising from leaf axils. Color ranges from purple to lavender to pink, rarely white. Individual flowers have a ¼-inch wide curved lower lip and a thin straight upper lip. The upper lip has a tuft of white hairs at the tip, the lower is hairy on the underside and lobed with a short rectangular extension at the tip that is notched in 2 parts. 2 brown-tipped stamens extend beyond the tip of the upper lip. A tubular calyx holds each flower.

Leaves and stem:

Leaves are coarsely toothed, 1 to 4 inches long and up to 1½ inches wide, rounded at the leaf base and tapering to a point at the tip, on leaf stalks up to 5/8 inch long. Leaves are hairy underneath and smooth or hairy on the upper surface. Attachment is opposite. The stem is a reddish brown color, square, and hairy to varying degrees.

Fruit:

The flowers drop off leaving the calyxes behind. Seed develops inside the calyx. The head turns dark brown as the seed ripens.

Seed is smooth, brown, oval, and just over 1 millimeter long.

Notes:

There are 2 varieties of Wild Bergamot in Minnesota, var. fistulosa, very common throughout the state, and var. menthaefolia, a more western species found in only a few Minnesota counties. The latter is a shorter, little branched plant with leaf stalks that are rarely over 3/8 inch long, but is otherwise very similar. Wild Bergamot is one of my favorite flowers. In full bloom, the flower head looks like a little fireworks display. It is an excellent garden plant. The dried leaves and flower heads are wonderfully aromatic; Bergamot oils have been used in natural healing for centuries.