B. Papp szerk.: Studia Botanica Hungarica 32. 2001 (Budapest, 2001)

Erzberger, Peter: Ditrichum crispatissimum (Muell. Hal.) Paris, a new species of the Hungarian bryoflora, and Ditrichum flexicaule (Schleich. ex Schwaegr.) Hampe in Hungary

character states differentiating between D. crispatissimum and D. flexicaule published after the detailed and well illustrated study of FRISVOLL (1985) are rather misleading (see Discussion). The following account is based essentially on FRISVOLL (1985), but since that paper might not be easily accessible, the main features are summarized in Table 1 and commented below (slight modifications based on observations of the author are included). Habit is very variable in both species. At one extreme there is D. flexicaule with very low, compact turfs (this morph is often called var. densum (B., S. et G.) Braithw.), and at the other we find tall lax cushions, which is the usual habit of D. crispatissimum. However, stunted forms of D. crispatissimum may have the apTable 1. Character states of Ditrichum crispatissimum and D. flexicaule (after FRISVOLL (1985), modified). Character Habit Height Flagellae Orientation of dry leaves Leaf length Leaf shape Subula length Leaf apex Cells (in the middle) of the sheathing part of the leaf Basal cells near costa Marginal cells Dorsal costa cells (in the middle of the sheathing part of the leaf) Auricles (Innermost) perichaetial leaves D. crispatissimum in lax tufts, strongly tomentose > 4 cm common straight > 3.5 mm sheathing base gradually tapering towards subula > 2/3 of total leaf length often denticulate far down the subula elongate with curved walls long,porose thin-walled, forming broad hyaline border merging into lamina shorter than adjacent lamina cells absent suddenly narrowed into subula D. flexicaule in dense tufts, usually less tomentose < 5 cm absent (except in arctic material) flexuose < 3 mm sheathing base abruptly narrowed into subula < 2/3 of total leaf length entire except a few denticulations at extreme apex isodiametric with straight walls short, eporose thick-walled, forming narrow hyaline border distinct from adjacent lamina longer than adjacent lamina cells often present gradually narrowed into subula