The reproduction method of lichen is-
1. Organogenesis: Organogenesis of lichens occurs by fragmentation and continuous process of death and decay.
2. Asexual reproduction: 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.
3. Sexual reproduction : The reproductive organs of lichens are ascocarps or basidiocarps. Sexual reproduction of lichens also occurs through plasmogamy. Male genitalia of lichens are called spermagonia and female genitalia are called carpogonia. Spermagonium produces pungametes and carpogonium produces strigametes. The male gamete and female gamete unite to form the zygote. The zygote germinates to form a new lichen.