Chemical analysis of representatives of a bout thirty genera of Lejeuneaceae has shown that the terpenoid and flavonoid content of the Lejeuneaceae is basically comparable to that of other Hepaticae and quite d iversified. Among the terpenoids detected , some are common throughout the family (elemenenes, germacrenes), others are distributed more restrictedly and are indicative of evolutionary relationships among genera , e.g. borneols (Nipponolejeunea), pinguisanines (Acrolejeunea complex),

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... atenes (Ptychanthoideae, Omphalanthus complex), calamenanes (Lopholejeunea) ~nd labdanes (Ptychanthus, Tuzibeanthus). Flavonoids are present in smaller amounts than terpenoids and comprise some compounds unique to bryophytes (Iu tonarin, kaem pferol-3-met hylet her). The genus Omphalanthus stands out by its total inability to biosynthesize flavonoids . At the species level the chemical constitution may vary considerably and in some species evidence for the existence of chemical races was detected. I NTRODUCTION