A mass of naked broomrape (var. purpurea) as seen at Catherine Creek in the Columbia River Gorge....................April 9, 2009. In this case, the basal leaves of their host plants (Saxifraga integrifolia) can be seen scattered amongst the stems of the naked broomrape.
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 minuta: Flowers 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.
In the Columbia River Gorge it may be found between the elevations of 100'-3000' between Stevenson, WA and Biggs, OR.
The photo above shows a close-up sideview of the tubular corolla of naked broomrape: Orobanche uniflora var. occidentalis. Note the numerous gland-tipped hairs over the outer surface of the corolla.
Photo above of Orobanche uniflora var. purpurea with one of its hosts, Saxifraga integrifolia var. integrifolia at Catherine Creek, Columbia Gorge Scenic Area.......March 30, 1991.