Broom-Rape Plants in Orange County, California

By Bob Allen

This is a brief guide to the genus Orobanche in this area. The whole story will be presented in the upcoming book,

Allen, R.L., C.M. Barhill, & F.M. Roberts, Jr. Field Guide to the Wildflowers of Orange County, California, and the Santa Ana Mountains. Includes the Chino Hills, Temescal Valley, and San Mateo Wilderness. In Preparation.

Check with Acorn Naturalists in Tustin about its availability, slated for the year 2006.

Orange County Broom-Rape Plants

1. Orobanche bulbosa G. Beck - Chaparral Broom-rape
2. Orobanche californica (Jepson) Heckard - California Broom-rape - Read the true story of its first discovery in Orange County.
3. Orobanche fasciculata Nuttall - Clustered or Pine Broom-rape
4. Orobanche parishiii (Jepson) Heckard var. parishii - Parish's Broom-rape

Orobanche bulbosa G. Beck - Chaparral Broom-rape Entire plant dark blackish, covered with short grayish sticky-tipped hairs. Arises from a very thick underground tuber. Deep purple flowers with two yellow stripes in the throat. Flowers are very small, corolla lobes are very short. Occasionally found, in the higher portions of the Santa Ana Mountains, often in loose decomposed granite soils Mostly parasitizes Chamise, Adenostoma fasciculatum (Rosaceae)

Orobanche californica Chamisso & Schlechtendal - California Broom-rape Possibly ssp. jepsonii (Munz) Heckard - Jepson's California Broom-rape Plant yellowy-brown, covered with whitish or yellowish sticky-tipped hairs. Flowers on short stalks, attached to a thick central stalk that is mostly underground. Flowers pale yellow-pink, with reddish veins. The corolla lobes are very long. Uncommon throughout its range. Here known only from the Lomas de Santiago above Foothill Ranch. Parasitizes California Goldenrod, Solidago californica (Asteraceae). Story of its local discovery

Orobanche fasciculata Nuttall - Clustered or Pine Broom-rape Plant yellowish, often suffused with purple, covered with whitish hairs Flowers soft yellow, on long more-or-less solitary stalks aboveground. Corolla lobes are very short. Commonly found, in major canyons and higher portions of the Santa Ana Mountains, in loose sandy soils, rocky areas, and talus slopes Parasitizes Yerba Santa, Eriodictyon crassifolium, and buckwheats, Eriogonum spp.

Important link for other broom-rape plants

Dan Nickrent of the Southern Illinois University, Carbondale, maintains a large site at:

http://www.science.siu.edu/parasitic-plants/Scrophulariaceae/Orobanche.Gallery.html

If you look on his site, scroll down to our common local species: Orobanche bulbosa and Orobanche fasciculata. Chris Barnhill, co-author of my wildflower book, took those photos. I'm actually in one of them!

Unless indicated otherwise, all photos are (c)2005 Bob Allen. Unauthorized use prohibited. Educational use is freely allowed (teaching) as is use by the printed news media (with credit to Bob Allen). Redistribution of the images or information is not allowed without permission.

Revised Monday, August 8, 2005.