The photo above shows a close-up sideview of the tubular corolla of naked broomrape: Orobanche uniflora var. purpurea. Note the numerous gland-tipped hairs over the outer surface of the corolla. Photographed on slopes above the John Day River at milepost 80 along Highway 19 east of Service Creek, OR........April 8, 2007.
Naked broomrape is an attractive perennial wildflower with single,erect floral pedicels from 5-15 cm high. The main stem is 0.5-2 cm long and is typically buried under the soil. The herbage is typically finely glandular-hairy.
The inflorescence consists of 1-3 flowers on long pedicels. The calyx is 6-12 mm long with the calyx tube from 2-4 mm long and the subequal lobes from 4-9 mm long. The corolla is 15-25 mm long and yellowish to purplish in color. The tube is curved with the lobes measuring 2-7 mm long with rounded, finely fringed tips. The anthers are 0.9-12 mm long, ranging from glabrous to woolly-pubescent.
Naked broomrape is parasitic on many saxifrages, sedums and members of the Asteraceae.
variety occidentalis: Flowers cream to light yellow to purplish with the throat not much expanded. Limb is small and does not expand much. The corolla measures 1.5-2.5 cm long. The anthers are glabrous.
variety purpurea: Flowers purplish with the throat fairly expanded and spreading. The limb is large and expands widely. The corolla measures 2-3.5 cm long. The anthers are woolly.
Naked broomrape may be found in open, moist grasslands or occasionally in moist woodlands from the lowlands to moderate elevations in the mountains.
Naked broomrape may be found from the Yukon south to southern California and east to Newfoundland and hence south to Florida.