Agastache Urticifolia, Horsemint Giant Hyssop

The stout stems of agastache urticifolia grow vertically upwards, reaching heights of around three feet. Stems and leaves may be hairless or finely hairy. Leaves grow at opposite intervals along the stems, and right beneath the flowers, which are produced in a dense cluster at the stem tips. Leaves are relatively thick, generally hairless, and toothed along the margins. Leaf surfaces are crossed by prominent, branched veins.

The inflorescence is a narrow cluster up to 6 inches long, subtended at the base by several pinkish-green bracts. Flowers have a short hairy, glandular calyx extending to five narrow, purplish lobes. The corolla is about half an inch long, colored white to pink, opening to two lips, the upper of which is divided into two lobes. The lower lip is larger, and angled downwards. Four stamens (two different-length pairs) project out beyond the corolla, as does a two-lobed style.