Kingdom: Plantae

Phylum: Magnoliophyta -- flowering plants

Class: Magnoliopsida -- dicotyledons

Order: Scrophulariales

Family: Orobanchaceae -- broomrape

Common Name: naked broomrape, oneflower broomrape

Species Code: ORUN

Origin: Native to open, moist places in grasslands and open forest over much of North America.

Rare: no

Form: forb, perennial, 5-15 cm tall, finely glandular-villous, lacking chlorophyll, root parasite; stems short, mostly subterranean, barely rising above the soil surface.

Mature height: 2-6 inches

Duration: perennial

Habitat Type: prairie

Wetland Indicator Status: FACU

Leaves: bract-like, alternate, lanceolate, glabrous, lacking chlorophyll.

Flowers: borne singly on a pedicel 3-10 cm long; calyx campanulate, 4-12 mm long with 5 subequal triangular lobes; corolla curved, 12-35 mm long, tubular, perfect, yellowish to purple, 15-35 mm long, bilabiate, the lobes rounded and finely fringed-ciliate.

Flower color: blue/purple, sometimes yellow

Bloom: April, May, June

Bloom starts on: late April

Bloom ends on: early June

Fruit: capsule 6-8 mm long, ovoid; seeds angled, reticulate, brown, less than 0.7 mm long.

Characteristics:
Thalesia uniflora in Piper & Beattie 1914.
The species is variable and a number of infraspecific taxa have been proposed but current practice is to reduce them all to synonyms.
Hitchcock et al (1969) recognized var. minuta and var. purpurea in the Pacific Northwest.
Davis (1953) recognized those two plus var. sedi in Idaho.
St. John (1963) recognized only var. minuta in southeastern Washington and adjacent Idaho.
Plants are root parasites of other plants. They have only rudimentary leaves and lack chlorophyll, emerging above ground only to flower.
Host plants on Kamiak Butte are probably Lomatium macrocarpum and Eriogonum heracleoides (Hufford 1997).
Parasitic on Lithophragma and Eriogonum (Piper & Beattie 1914).
Parasitizes roots of Saxifragaceae (Davis 1953).
Usually parasitic on Sedum or members of Asteraceae and Saxifragaceae (Hitchcock et al 1969).
Reproduces sexually by seed.
n=18, 36 (Hitchcock et al 1969).
2n=36, 48, ±70 (Baldwin et al 2004)
Multiple ploidy levels are present and apomixis may occur in some polyploids (Heckard & Chuang 1975).
Fruit is a capsule.
Has medicinal uses as an astringent (Winegar 1982).

Sun requirement: O. uniflora does not photosynthesize and thus has no sun requirement itself, but many of the hosts require full sun.

Soil moisture: xeric to mesic

Fire: roots probably survive most fires

Hazards: non-native members of the genus are often considered noxious weeds

Sowing time: no information available

Transplant time: no information available

Stratification: no information available

Seed yield: no information available

Seed harvest: difficult

Seed first harvest: no information available

Seed cleaning: no information available

Planting duration: no information available

Seed insect problem: no information available

Seed shatter: no information available

Seed size: small

Seed harvest date: no information available

Herbaria: Specimen data and digital resources from The Consortium of Pacific Northwest Herbaria

Keywords: native perennial upland forb

Propagation:
There is no information on propagation. Seed is probably best sown in the fall near host plants.

Notes: Orobanche uniflora is a parasite on the roots of other plants. The only time it comes above the ground is to flower, which it does in late April and early May. Otherwise, one would never know it is around. The flowers are purple and born on a short stalk about 4 inches tall. Don’t know how to grow it, but it is probably best to sow seeds among suitable host plants. Common names include naked broomrape, one-flowered broomrape, cancer drops, one-flowered cancer-root (Skinner et al 2005).

References:
Baldwin, B.G., S. Boyd, B.J. Ertter, D.J. Keil, R.W. Patterson, T.J. Rosatti, and D.H. Wilken (eds). 2004. Jepson Online Interchange for California Floristics. University and Jepson Herbaria, University of California, Berkeley, CA. Accessed 11/26/09 online at http://ucjeps.berkeley.edu/interchange.html

Cassera, Josephine D. 1935. Origin and Development of the Female Gametophyte, Endosperm and Embryo in Orobanche uniflora. Bulletin of the Torrey Botanical Club 62:455-470.

Davis, Ray J. 1952. Flora of Idaho. Wm. C. Brown, Dubuque, Iowa. 827 pp.

Heckard, L.R., and T.I. Chuang. 1975. Chromosome Numbers and Polyploidy in Orobanche (Orobanchaceae). Brittonia 27:179-186.

Hitchcock, C. Leo, Arthur Cronquist, Marion Ownbey, and J.W. Thompson. 1969. Vascular Plants of the Pacific Northwest. University of Washington Press. Seattle, WA. 5 vol.

Hufford, Larry. 1997. The Plants of Kamiak Butte. Marion Ownby Herbarium, Washington State University. Pullman, WA. Accessed 12/5/09 online at http://www.wsu.edu:8080/%7Ewsherb/kamiak.htm

Piper, C.V., and R.K. Beattie. 1914. The Flora of Southeastern Washington and Adjacent Idaho. Press of the New Era Printing Company, Lancaster, PA. 296 pp.

Skinner, David M., Paul Warnick, Bill French, and Mary Fauci. 2005. More Palouse Forbs for Landscaping. USDA NRCS Pullman Plant Materials Center and Palouse Prairie Foundation. Online at http://www.wsu.edu/pmc_nrcs/Docs/More_Forbs_for_Landscaping.pdf

St. John, Harold. 1963. Flora of Southeastern Washington and of Adjacent Idaho. 3rd edition. Outdoor Pictures. Escondido, CA.

Winegar, David. 1982. Desert Wildflowers: Drylands of North America. Beautiful America Publishing Co. Beaverton, OR.

Links:
Plant Profile from the USDA PLANTS Database
Species information from the University of Washington Herbarium