Broomrape Family

Dense-flowered Owl’s-clover © TCorelli

Orobanchaceae (or-o-ban-KA-see-ee)

Iconic Features

  • All species partially or completely parasitic
  • Plants lacking chlorophyll have leaves reduced to fleshy scales
  • Flowers bilaterally symmetrical

Description (Jepson)

  • Eudicotyledons (eudicots) – a major lineage of flowering plants including most plants traditionally described as dicots and generally characterized by
    • 2 seed leaves (dicotyledon)
    • Netted (reticulate) leaf venation
    • Flower parts in fours and fives
    • Pollen grains with 3 pores (tricolpate)
    • Vascular bundles in stem arranged in a ring
    • Taproot system
  • Annual herbs or perennial herbs or shrubs
  • Leaves
    • Generally simple (not divided into leaflets)
    • Reduced to fleshy scales in plants lacking chlorophyll (holoparasitic)
    • Usually alternate (1 leaf at each junction with stem)
  • Flowers
    • Inflorescence (flower arrangement) in many forms
      • Usually with bracts (modified leaves) at base
    • Bisexual and bilaterally symmetrical flowers
      • 2 fused upper petals and 3 fused lower petals, arranged like lips
    • Ovary superior (above the attachment of other flower parts)
  • Fruit is a capsule (a dry, multi-chambered fruit that splits open at maturity) with many tiny seeds

Notes

  • Approximately 2,060 species worldwide
    • Includes owl’s-clover, paintbrush, warrior’s plume, cream sacs, and broomrapes
  • Only plant family with both completely-parasitic (holoparasitic) and partially-parasitic (hemiparasitic) species
    • Holoparasitic – plants lack chlorophyll and depend on host for nutrition (e.g. clustered broomrape)
    • Hemiparasitic – plants have chlorophyll, but take some water and nutrients from other plants, sometimes species-specific hosts (e.g. warrior’s plume)
  • Modified roots (haustoria) grow into the host plant
  • Distinct from myco-heterotrophs, such as coralroot orchids, which also lack chlorophyll but have a symbiotic relationship with fungi
  • Some species have significant economic impacts by damaging commercial crops
    • Branched broomrape (Phelipanche ramose), which is especially damaging to tomatoes, causing up to 80% loss in Chilean tomato crops. has recently re-emerged as a threat in California (Osipitan et al. 2020)
  • Scientific name from the included genus Orobanche, from the Greek orobos, “a vetch,” and anchone, “strangle,” alluding to its parasitic nature
  • Common name from the word “broom,” referring to various shrubs in the Pea family, and the Latin rāpum, “tuber”; thus referring to the parasitizing of broom roots by members of this family
  • Represented by 14 species at Edgewood

See General References

Specific References

    Osipitan, O.A. et al. 2020, Aug. 12. Getting familiar with branched broomrape: a parasitic weed in California processing tomato. UC Weed Science.

    Browse Some Edgewood Plants in this Family