How does witchweed grow?

An annual plant, witchweed overwinters in the seed stage. Its seeds germinate in the presence of host root exudate, and develop haustoria which penetrate host root cells. Host root exudate contain strigolactones, signaling molecules that promote striga seed germination.

What is unique about witchweed?

Commonly known as 'witchweed,' the parasitic plant Striga hermonthica devastates crops in sub-Saharan Africa. Scientists have discovered a unique protein in Striga that helps sustain its high transpiration. ... In transpiration, water is carried through plants and evaporates from their leaves via stomata (breathing pores).