Yellow Giant Hyssop (Agastache nepetoides)

 

Yellow Giant Hyssop  (Agastache nepetoides)

Yellow giant hyssop is a tall, native perennial of Wisconsin’s savannas and rich woodlands, where it contributes steady mid‑ to late‑season nectar for bees, butterflies, and other pollinators. Most plants grow five to six feet tall, with pale yellow flowers held in dense vertical spikes that may reach four to sixteen inches. Individual blossoms are small, about a third of an inch long. The opposite leaves are thin, coarsely toothed, and somewhat egg‑shaped with a rounded base, often up to six inches long and three inches wide on long stalks. The species favors mesic, fertile soils in part shade but can tolerate full sun when moisture is reliable. In Wisconsin it appears in savannas, open woods, thickets, meadows, and along fencerows, thriving in moist to moderately dry conditions without extending into truly dry uplands or saturated wetlands.

Sources: 

Wisconsin State Herbarium — Agastache nepetoides specimens

Flora of Wisconsin — Agastache nepetoides entry

USDA Plants Database — Agastache nepetoides profile

Illinois Wildflowers — Yellow Giant Hyssop

Minnesota Wildflowers — Agastache nepetoides

BONAP — Agastache nepetoides county distribution map

NatureServe Explorer — Agastache nepetoides species account

(SF)