Asexual reproduction of lichens occurs through the production of spores.
(i) Soredium : Soredium is a tiny body of algae covered with fungi. It is dispersed by wind and germinates in favorable conditions to form new lichens.
(ii) Isidium : Isidium is a tiny papilla like spore. It grows and metamorphoses to form new lichens.
(iii) Pycnidium : Pycnidiospores are produced inside the pycnidium. Pycnidiospores germinate to form new lichens.
(iv) Phylidium : Leaf-like phyllidia are produced in foliose lichens. Lichens reproduce by phyllidia.