ON THE TAXONOMY AND PHYLOGENY OF FLEISCHEROBRYUM (MUSCI, BARTRAMIACEAE)

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  According to “Index Muscorum” the genus Fleischerobryum Loeske has four species, S (Hampe) Loeske, F. macrophyllum Broth., F. eurybrochis (Ren. & Card.) Fleisch., and F. wallisii (C. Müll.) Loeske. The two latter belong to the related genus Philonotis Brid. and have been synonymized.

  The capsule of Fleischerobryum shows several primitive characters: The position of the capsule is horizontal or slightly pendulous, the capsule is long cylindrical or slightly asymmetric, the neck is large, ca one third of the length of the capsule, and the striae of the exothecium of Fleischerobryum are less regularly organized than are the striae in Philonotis species with ovoid or gibbous and horizontal capsules. Evolutionary lines from the primitive capsule of Fleischerobryum both to gibbous and regularly striate capsules, and to upright smooth capsules with reduced peristomes are possible. Fleischerobryum macrophyllum and F. longicolle have wide mammillose basal leaf cells and narrower more distinctly mammillose/papillose cells in the apical leaf like some Philonotis species. In the basal cells the mammilla is proximal, and in the distal cells the papilla/mammilla is distal. In the mid-leaf cells of Fleischerobryum, cells both with central papillae and with distal papillae are present. In Philonotis, with a few exceptions, the site of the papillae/mamillae is fixed either to the distal end or proximal end of the cell, on both cell ends, or papillae are central on the cell. A hypothesis is here presented that the ancestor of Philonotis, and possibly of all Bartramiaceae, was a plant having a capsule similar to that of the Fleischerobryum, and wide and smooth leaf cells.