Broomrape

Orobanche

Broomrapes are a genus (Orobanche) of parasitic plants, members of the family Orobanchaceae. There are 11 genera and about 130 species of broomrape, generally found in warm or temperate regions.

The broomrape plant is small, only 4 to 12 inches tall. It is best recognized by its yellow-to-straw colored stems and blue or white, snapdragon-like flowers. The flower shoots are scaly, with a dense terminal raceme. The leaves are merely triangular flaps. The seeds are minute, tan-to-brown and blacken with age. These plants generally flower from February through May.

The broomrapes are totally parasitic on the roots of other plants and as such have no chlorophyll. Each broomrape seed puts out a root-like growth, which attaches to the roots of nearby hosts. Once attached to a host, the broomrape robs its host of water and nutrients.

Some varieties are able to parasitise a single plant species, e.g. Ivy broomrape , Orobanche hederae, is restricted to parasitising Hedera helix. Others can infect a whole family, such as the Lesser broomrape , O. minor, on Trifoliata and possibly other Papilionaceae.

Branched Broomrape , Orobanche ramosa, is considered a major threat to crops of the United States. Several crop plants that are parasitized are tomato, eggplant, potato, cabbage, coleus, bell pepper, sunflower, celery, and beans. In heavily infested areas, Branched Broomrape can cause total crop failure.

Species (not a complete list)

• Fascicled Broomrape , Orobanche fasciculata
• Desert Broomrape , Orobanche ludoviciana
• Gray's Broomrape , Orobanche grayana
• Nodding Broomrape , Orobanche cernua
• Naked Broomrape , Orobanche uniflora