Some names are better than others…
The Broom rapes are members of the Orobanche genus, which is Greek for “Strangling bitter vetch”, which may or may not be better than the common name. The common name derives from the fact that the plant was originally described as a destructive parasite upon Broom plants (Cytisus spp.) in Southern England.
Broom rape is a holoparasitic angiosperm (flowering plants that are wholly - “holo” - parasitic upon their host) which has no chlorophyll, and no ability to make its own nutrients. Its leaves are often no more than minute scales, as they serve no purpose in a non-phtosynthesizing plant.
Since these species do not have chlorophyll, they usually have brownish or straw-colored stalks, with brown, yellow, or purple flowers.
The way that these plants get their nutrients is by directly tapping into the roots of their hosts by way of haustoria - a “root” tip that can dig into a host plant and siphon off the products of photosynthesis that the host tries to send down into its root system.There are Orobanche species that parasitize almost every non-woody angiosperm native to Europe and the Near East, but they are currently found throughout the world. One of the most threatening species is Orobanche ramosa, branched broomrape, which parasitizes the Solinaceae family (including tomatoes, tobacco, potatoes, and eggplants) throughout Southwestern Europe.
Broom rape! Not a nice name for not a nice genus.
Images:
(via biomedicalephemera)
