Broomrapes - Orobanche spp

Broomrapes Orobanche spp are a parasitic plant group without chlorophyll. They can be very variable and difficult to pin down to a species, so we have chosen to deal with them all together. There are 14 species and 5 subspecies recorded for this area. To identify them to species level take a specimen (one of the few times we recommend picking a wildflower) and use a good field guide such as The Wildflower Key by Francis Rose or Flowers of Europe by Oleg Polunin, carefully reading the descriptions and not relying too much on picture matching. If you read French then Tela Botanica is also very useful. Note that it can actually be unhelpful to know the host plant, as broomrapes often grow some distance from the plant they are tapping in to the root system of. Do not base your identification solely on the presence of a particular host species.

To identify them you need to check:
  • colour and how close together the stigma lobes are (these are two little bobbles on a stalk inside the flower).
  • whether individual flowers are straight or curved in profile.
  • the number of bracts with each flower (don't confuse these separate bracts with the calyx in which the flower sits).
  • the shape and size of the 'lower lip' of each flower.
  • how hairy or sticky the stamen stalk is (inside the flower).
  • is the flower sweetly scented? If so it is Thyme or Bedstraw Broomrape.
Scientific Name / English Name / French Name / Host:
O. alba / Thyme Broomrape /Orobanche blanche ou du Thym / Thyme, mints and deadnettles.
O. amethystea / Amethyst Broomrape / Orobanche couleur d'améthyste, du panicaut ou violette / Eryngium.
O. arenaria / Sand Broomrape /Orobanche des sables ou lisse / Wormwoods Artemisia spp
O. caryophyllacea / Bedstraw or Clove-scented Broomrape / Orobanche commune, du gaillet, giroflée ou a odeur d'oeillet / Bedstraws Galium spp.
O. gracilis / None /Orobanche grele ou sanglante / certain members of the Pea family.
O. hederae / Ivy Broomrape /Orobanche du lierre / Ivy.
O. minor / Common or Lesser Broomrape /Orobanche du tréfle ou Petite Orobanche / Pea family, especially clover, and Daisy family.
O.minor subsp minor
O. picridis (syn. O. artemisiae-campstris) / Oxtongue or Picris Broomrape /Orobanche de la Picride ou du Picris / Oxtongues Picris spp and Hawks-beards Crepis spp.
O. purpurea / Yarrow or Purple Broomrape /Orobanche pourpre, pourprée ou violette/ Yarrows Achillea spp, Wormwoods Artemisia spp, Thistles Cirsium spp.
O. ramosa / Branched or Hemp Broomrape / Orobanche du chanvre ou ramifiée / Hemp, tobacco, potato, tomato.
O. ramosa subsp ramosa
O. ramosa subsp mutelii / Mutel's Hemp Broomrape.
O. rapum-genistae / Greater Broomrape / Orobanche du genet / Gorse, Brooms.
O. rapum-genistae subsp rapum-genistae
O. reticulata / Thistle Broomrape /Orobanche réticulée / Thistles and teasels.
O. reticulata subsp pallidiflora
O. rubens / None / Orobanche rouge ou jaune / Lucerne and other members of the pea family.
O. teucrii / None / Orobanche de la germandrée / Germanders Teucrium spp.

Curiously, Knapweed Broomrape O. elatior (syn. O. major) does not seem to occur in this area.

5 Key Characters:
  • dense flower spikes 10 - 45 cm high.
  • flowers and stems cream, usually with a wash of red, brown, yellow or violet.
  • no leaves, but some pale leaf like 'scales' on the stems.
  • never any green parts.
  • flowers tubular with rather frilly open 'mouths'.
Lookalikes: It is very easy for beginners to mistake Broomrapes for orchids, but once you have a bit of practice in the field you can separate them easily. Orchids usually have leaves and chlorophyll (ie green parts) and their flowers are never tubular (although many have a nectar spur on the back). Broomrapes may also be mistaken for their parasitic relative Toothwort Lathraea squamaria, which has all the flowers on one side of the stem and does not have 'open mouthed' flowers like Broomrapes.

Habitat: Grasslands, roadsides, garden beds, woodlands - anywhere there are suitable hosts.

Flowering Period: May-June-July.

Status: Several species are common and widespread, such as Common Broomrape (on clover), others such as Yarrow, Greater, Thyme and Oxtongue Broomrapes are locally common. Several are rare and have restricted ranges, for example Sand and Thistle Broomrapes.

Photographed by Loire Valley Nature:

Photographs are numbered from left to right and top to bottom. All photographs will enlarge in a new window if you click on them. 1 - 2 Orobanche sp in our orchard, May.

Ivy Broomrape, showing this species characteristic brownish purple stem and short cream tubular flowers with purple streaks. If you look carefully at the top flower facing the camera you can see that the stigma lobes are yellow. The host plant Ivy is just visible in the background on the left.
Amethyst Broomrape can be distinguished from Common Broomrape by a longer corolla (flower tube), up to 25 mm, and a distinctly divided upper 'lip'. The lobes of the flower tube spread open and curve back as the flower ages.

Despite its name, Amethyst Broomrape is usually a reddish-brown rather than a violet-purple colour.

Amethyst Broomrape, closely related to Ivy Broomrape, almost exclusively parasitising Field Eryngo Eryngium campestres (the spiky plant between the two Broomrapes).


  1. Orobanche - currently my most hated weed in Australia. They seem to be comingup everywhere where previously I was virtually unaware of them. I'm constantly pulling them out of my front garden, but they seed so prolifically. And I've even seen them out in the bush. Seems there are two species in NSW - O. minor and O. cernua.

  2. Harvey: The one you really don't want is O. ramosa. I mostly get O. minor in the orchard (lots of clover for it to latch on to), but there are some lovely rare ones in the area that I get to see on botany outings.