Conopholis americana aka American Cancer Root

Conopholis americana is a small perennial herb in the Orobanchaceae family. Common names include bear corn and American cancer-root. Its native range spans eastern Canada and the central and eastern United States. It also includes southern Mexico, Costa Rica, and Panama. This plant lives as a parasite on oak roots. It has no chlorophyll and cannot make food through photosynthesis. Instead, the host tree supplies its nourishment. Despite its name, no evidence links it with cancer.

Plants reach about 0.25–0.67 feet [0.08–0.20 metres] tall. Each is about 0.08 feet [0.025 metres] wide. The fleshy stems stand upright and do not branch. They measure about 0.04–0.08 feet [0.013–0.025 metres] thick. The plant has scales rather than true leaves. These pointed scales range from brown to yellow-tan. Some are egg-shaped, while others are narrow and lance-shaped. They sit beneath the flowers on the upper stalk. The stems lack both hairs and scent.

Dense flower spikes look like small cones or corn cobs. Their blooms range from cream to golden yellow. Each tubular flower hangs downward and has a swollen base. Flowers open from the spike's base toward its tip. Bloom may begin in April in warmer places. Elsewhere, spikes may appear as late as July. Each flowering period lasts about three weeks. The spikes then wilt, turn brown, and dry. Each flower gives way to a capsule holding many small seeds. These capsules are longer than they are wide.

Growth is slow, and much of it takes place underground. Spikes first emerge when plants are about four years old. Several spikes may share one root system. Its attachment points cause large, rounded swellings on oak roots. Woodland sites with rich organic soil suit this plant. It needs good drainage and tolerates moist or sometimes dry soil. It grows in shade, dappled light, partial shade, or full sun. The listed hardiness range covers USDA zones 3–9. Its reliance on oak roots remains central to its growing needs.

Bear corn adds spring and summer interest to native woodland gardens. The source lists low upkeep and no known diseases or insect pests. New plants spread through seed. Black bears eat the flower spikes after leaving hibernation. Deer sometimes browse them too. These animals may help move seeds, though this remains uncertain. Wildlife feeding does not establish safety for human food use. The supplied sources give no human edibility or toxicity assessment.