A Revision of the Infrageneric Taxa of Fissidens

Fissidens Subgenus Aloma (Bryophyta) in Tropical Africa I. the Large-Celled Costate and Ecostate Species

“…This species is therefore included in the key below. All ecostate species have large cells but not all large-celled species are ecostate (Pursell & Bruggeman-Nannenga 2004). The present paper is a revision of those tropical African species of subgenus Aloma that have large (longer than 30 µm), smooth laminal cells.…”

“…These species appear ecostate, yet many have or can have vestigial costae (Salmon 1899;Pursell & Bruggeman-Nannenga 2004) which occasionally can reach as far as the length of the vaginant lamina (e.g., in Müller Z215, F. usambaricus and the lectotype F. enervis Sim). Such weak costae have the same arrangement of cells as the bryoides-type costa with two large adaxial and one large central cell, but differ from well-developed bryoides-type costae in having thinner cell walls and absent or poorly developed lateral bands.…”

“…This paper follows the classification by Pursell and Bruggeman-Nannenga (2004), who emphasized sporophytic characters. They considered large-celled limbate species to belong in subgenus Aloma, as they have Aloma sporophytes, 1 and classified limbate species with small, smooth cells in subgenus Fissidens because of their subgenus Fissidens sporophytes.…”

“…embraces a wide range of gametophytic types (Pursell & Bruggeman-Nannenga 2004). Five not sharply distinct groups can be recognized: one without costa, one with large (over 30 µm long) cells, one with pluripapillose cells, one with unipapillose cells and one with smooth cells.…”

“…Five not sharply distinct groups can be recognized: one without costa, one with large (over 30 µm long) cells, one with pluripapillose cells, one with unipapillose cells and one with smooth cells. Because of the existence of transitional species, these groups are no longer recognized as taxa (Pursell & Bruggeman-Nannenga 2004). Fissidens subgenus Aloma includes elimbate, semilimbate and a few completely limbate species, and the laminal cells are small, mediumsized or large.…”