Category: Lichens

STUDY OF EXTERNAL FEATURES OF THALLUS (FRUTICOSE LICHENS) These appear shrubby with cylindrical, flat or ribbon-like body. It is upright, generally branched and pendulous. It remains attached to the substratum by rhizoidlike structures forming a disc. The common examples include Usnea, Alectonia, Cladonia, etc.   STUDY OF INTERNAL STRUCTURE​ OF THALLUS (FRUTICOSE LICHENS) The transverse…

STUDY OF EXTERNAL FEATURES OF FOLIOSE LICHENS The foliose lichens have a flat, leaf-like, lobed or deeply incised thallus. It is attached to the substratum only at certain points by rhizines. Rhizines are rhizoid-like outgrowths which arise from the under surface. The thallus may be attached to the substratum either by a single rhizine or…

STUDY OF EXTERNAL FEATURES OF CRUSTOSE LICHENS The crustose lichens are hard, granular crusts on rocks and bark of the trees. These adhere very closely and firmly to the substratum. The thalli are partially or completely embedded in the substratum. These lichens are generally ash-coloured. However, the colours may vary. The surface of the thallus…

STUDY OF EXTERNAL FEATURES OF THALLUS (BASIDIOLICHENS) The basidiolichens are tropical in distribution and are found growing upon bare soil, rocks and trees. There are only three genera of basidiolichens and out of these Cora pavonia is the best known. The thallus is much lobed, internally attached to the substratum by rhizines and resembles superfically…