Orobanche cernua (nodding broomrape).

O. cernua is an obligatory, non-photosynthetic root parasite which is native over a wide range across northeast Africa, southern Europe and western and southern Asia. In many of these areas it is a serious pest of Solanaceaeous crops such as Solanum lycopersicum (tomato) Nicotiana tabacum (tobacco) and S. melongena (aubergine) and occasionally S. tuberosum (potato). Species of Orobanche depend totally on their hosts for all nutrition and become an active sink for the host plant. This therefore results in a decrease in crop yield and as a result can have a major impact on the economy and livelihoods. Once established, the seed bank may last 10-20 years and there are no simple, economic control measures. Seeds of O. cernua are very small and inconspicuous and can be accidentally introduced into new areas as a contaminant of soil, seeds and machinery. There is potential for this species to invade many other areas of the world.