| Research Abstract |
Species of the genus Ramalina collected mainly in Japan (30 taxa) and South America (182 taxa) are investigated for their chemical variations and their relationships with respect to morphology and phytogeography. The diagnostic medullary substances found in species of Ramalina are orcinol depsides, beta-orcinol depsidones and fatty acids. Present study revealed that species in the sugenus Fistularia show 1 to 2 chemical variations in each species, whereas species of the subgenus Myelopoea usually have 3 to 5 chemical races. The variation fall in 1) additional, 2) replace and/or chemosyndrome types. Ramalina usnea, in contrast, shows 11 chemical variations of the chemosyndrome-type. In this species, fatty asid (bourgeanic acid) race shows strong correlationship with its distribution. Total 53 taxa of the section Myelopoea chemical deficient races, whereas section Fistularia has no chemical deficient ones.
Anatomical characters of apothecia and thalli can be considered very useful taxonomic characters. Two types of chondroid tissues are recognized in Ramalina; smooth, non-cracked chondroid tissue and cracked chondroid tissue. All species of the subgenus Fistularia have non-cracked chondroid tissue and species of the subgenus Myelopoea has one of the two types of chondroid tissue. The type is always constant in each species. Anatomical characters of apothecia such as characters of proper exciple and supportive tissue below hypotheicum are also considered as useful characters in the present genus.
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