Abstract:
A taxonomic revision of the family Thuidiaceae Schimp. for Africa and the east African Islands is
presented. Three genera, namely, Pelekium Mitt., Thuidiopsis (Broth.) M. Fleisch. and Thuidium
Bruch & Schimp., and 16 species are accepted and revised for the region. The nomenclature, keys
to genera and species, descriptions, illustrations and distribution maps are included.
Thuidiaceae is one of over 40 families that belong to the Hypnales which is known to
contain the most diversity among pleurocarpous mosses. Members of the Thuidiaceae are
characterised by gametophytes with attractive, regularly 2- or 3-pinnate branching, presence of
paraphyllia on surfaces of stems and branches, dimorphic stem and branch leaves, longitudinally
plicate leaves with a single costa, papillose leaf cells, and a hypnoid peristome. Abietinella Müll. Hal., Haplocladium (Müll. Hal.) Müll. Hal., Hylocomiopsis Cardot and
Rauiella Reimers are excluded from African Thuidiaceae. Thuidium involvens var. thomeanum
Broth. is raised to species status under Pelekium, as Pelekium thomeanum (Broth.) Phephu.
Thuidium pseudoinvolvens (Müll. Hal.) A. Jaeger is also transferred to Pelekium and the new
combination Pelekium pseudoinvolvens (Müll. Hal.) Phephu is proposed.
