Monarda is a fascinating example of parallel evolution: it makes a display by clustering small ray-like flowers together in one head so closely that the head is often taken for a single flower. In other words, it adopts the method of the Compositae. This particular species is bright red, which is a very attractive color to hummingbirds. It is otherwise very similar to Wild Bergamot (M. fistulosa), which is rather more common around here.
This is a native perennial, but much used as an ornamental planting, so that it is difficult to distinguish truly wild populations from garden escapes. These plants are probably truly wild; both grew in North Park, where they were blooming in the middle of July. The species is very adaptable to different light conditions: one of these plants was growing in full sun,and the other deep in the woods where a fallen tree had opened up the sky just a bit.
Gray describes the genus and the species:
MONÁRDA L. HORSE MINT. Calyx 15-nerved, usually hairy in the throat. Corolla elongated, with a slightly expanded throat; lips linear or oblong, somewhat equal, the upper erect, entire or slightly notched, the lower spreading, 3-lobed at the apex, its lateral lobes ovate and obtuse, the middle one narrower and slightly notched. Stamens elongated, ascending, inserted in the throat of the corolla. — Odorous erect herbs, with entire or toothed leaves, and large attractive flowers in a few verticels closely surrounded by bracts. (Dedicated to Nicolás Monardes, author of many tracts upon medicinal and other useful plants, especially those of the New World, in the latter half of the 16th century.)
Stamens and style exserted beyond the linear straight acute upper lip of the corolla; heads solitary and terminal or sometimes 2 or 3; leaves acutely more or less serrate; perennials.
Leaves petioled; calyx-teeth scarcely longer than the width of the tube.
Glabrous or villous.
Calyx smooth or smoothish in the throat.
M. didyma L. (Oswego Tea, Bee Balm.) Stem somewhat hairy, 2 m. or less high, acutely 4-angled; leaves ovate-lanceolate, acuminate, the floral ones and the large outer bracts tinged with red; calyx smoothlsh, nearly naked in the throat; corolla smooth or minutely pubescent, 4-5 cm. long, bright red, showy. — Moist woods, by streams, w. Que., Out., and south w. July, Aug.