Silphium trifoliatum

When the whorled rosinweed is in bloom in midsummer, a layer of sunny flowerheads can be seen softening the transition from meadow to sky. At the center of each flowerhead, tubular florets draw in long-tongued pollinators like bumble bees and butterflies. The plant’s leaves encircle its tall stem, creating an attractive look even when the flowers aren’t in bloom.

One of the more easterly distributed members of the silphium genus, whorled rosinweed is tolerant of light shade in addition to full sun, and it occupies woodland openings as well as meadows. If growing at the edge of a tree canopy, however, the plant has a tendency to lean toward the sun. Whorled rosinweed grows well in soil moisture ranging from moderately wet to moderately dry, forming small colonies through the production of short underground stems. Attaining a mature height of 5 – 8’, this plant is a long-lived perennial that reliably blooms in midsummer year after year.

References: 1,2,3,4,5.

Photo by Julie Slater.