Aspects of plant intelligence: an answer to firn

In a recent 'Invited Review', I stated the case for plant intelligence, provided definitions and outlined some of the consequences, illustrating them with examples. A short critique of this concept by Firn is given in the preceding 'Viewpoint' and rebuttals of the criticisms it contains are presented in the present article. The importance of plant intelligence as an emergent property resulting from interactions and communication of the component tissues is re-stated. The contentions made by Firn that plants are collectives of physically joined organs but acting in relative isolation of each other is subject to critical analysis and found to be contradicted by much established literature. Viewing plants as expressing intelligent behaviour should lead to better understanding of their ecological success and indicate experiments to test the basic concept. (C) 2004 Annals of Botany Company