One-flowered Broomrape (Orobanche uniflora) Linnaeus, 1753 |
Other names: One-flowered cancer root, ghost pipe, naked broomrape |
Orobanche uniflora occurs throughout most of temperate Canada, and the United States, e.g., from British Colombia to Newfoundland, south to California and Texas (Map). It grows in coniferous, mixed and deciduous forests and woodlands, thickets, meadows, prairies, stream banks, and cliffs, in lowlands and mountains; often in moist rocky areas. O. uniflora is an annual or perennial holoparasitic herb obtaining nutrients from roots of other plants, mostly of the Asteraceae, Crassulaceae, and Saxifragaceae, through a system of feeder roots (haustoria); it does not produce chlorophyll. The stem is under the ground, and only the flowering stalks are visible (5-15 cm tall, pale gray or tan, covered with fine glandular hair); 1-5 stalks per plant. Each produces a single flower with a short hairy calyx, and a tubular corolla with 5 lobes. The corolla is white to violet (rarely purple), covered with short fine hairs. This species flowers in May-June; pollinated by bumblebees or self-pollinate. The fruit is an ovoid capsule.