The yellow false foxglove is a splendid addition to the summer woodland flora of Illinois.
Aureolaria grandiflora (Benth.) Pennell.
Woods. July - August.
On the hogback ridge where the black oaks and ironwoods grow in heavy clay soil, the graceful plants of the yellow false foxglove stand tall in the splashy sun and shadow of the ridge woods. The foxglove plant has many willowy stems three feet tall or more, abundantly leafy with leaves deeply toothed, somewhat folded, grey-green; in the axils of the leaves are the bright buttercup-yellow buds. At first they are round. Then they elongate and open as a large tubular blossom often two to three inches long, with a broad, open face of five petal divisions and a deep, shining, golden throat. The flower glistens much as a buttercup or a marsh marigold does, and is almost like a garden flower misplaced there in the oak country or dry clay soil of the hogback. But the yellow false foxglove could not live in the garden. This plant is a semi-parasite on the roots of oak trees, and such parasites are firmly anchored to their chosen host in their chosen haunt and cannot be moved. Unlike many true parasites, the false foxglove has green leaves which manufacture most of their own food. The roots are fastened to the roots of the host, from which some food and moisture are obtained.
In August and September the yellow false foxglove opens its dramatically beautiful flowers; they turn brown and drop away, and more buds open during a period of several weeks. The interesting, blackened stalks of seed pods remain all winter.