On the basis of internal structure of thallus, the lichens are divided into two groups, namely, homoiomerous and heteromerous lichens. 1. Structure of Homoiomerous Lichen Thallus: In the gelatinous lichen thalli such as Collema and Leptogium, the thallus shows a simple structure with little differentiation. It consists of a loosely interwoven mass of fungal hyphae with algal cells equally distributed [...]
In this article we will discuss about the modes of reproduction in lichens. A. Reproduction of Lichen Thallus: It multiplies by vegetative methods of fragmentation and also by the formation of highly differentiated propagules as follows: (i) Fragmentation: It consists in the breaking up of the established thalli into segments which are distributed to start new growths. Fragmentation is accomplished [...]
In this article we will discuss about the economic importance of lichens. A. Useful Aspects: (a) Ecological significance: (i) Pioneer colonizers: Lichens are said to be the pioneers in establishing vegetation on bare rocky areas (lithosere). They are the first members to colonize the barren rocky area. During development they bring about the disintegration of rock stones (biological weathering) by [...]