7.5 Parasite Attraction

Dodder (Cuscuta pentagona) is a parasitic plant. Immediately after germination, it must attach itself to a host plant to survive, because its photosynthesis capacity is extremely low.

A 2006 study showed that dodder does not choose hosts randomly — it is guided by volatile chemical compounds emitted by nearby plants. Tomato plants, for example, produce molecules that are highly attractive — more than those produced by wheat.

So — does dodder smell nearby plants and choose the one it prefers?

What changes if we rephrase that question without anthropomorphism?

Is this extraordinary behaviour evidence of intelligence — or an automatic biochemical mechanism?