A REVISION OF POGONATUM SECT. RACELOPUS, SECT. NOV., INCLUDING RACELOPUS DOZY & MOLK., PSEUDORACELOPUS BROTH., AND RACELOPODOPSIS THÉR.

抄録

  The genera Racelopus Dozy & Molk., Pseudoracelopus Broth., and Racelopodopsis Thér. form a group sharing a scabrous seta and a strong trend toward reduction in size and structure of the gametophore. They are considered insufficiently distinct from Pogonatum P. Beauv., and the species are accommodated in Pogonatum sect. Racelopus (Dozy & Molk.) Touw, stat. nov., also including P. neo-caledonicum Besch. All species occur in tropical Southeast Asia or adjacent regions and grow in humid evergreen forest. Nine species are recognized that are put in two groups. One group consists of 2 species that are tall colonists characterized by complanate, anisophyllous stems. The other group consists of more or less dwarfed shuttle species. Morphology and distribution of the latter suggest that its ancestors invaded tropical Asia from the Southeast. The paper contains a historical review, a morphological survey of the group, a preliminary discussion of its relationship to other groups in Pogonatum, general notes on distribution and ecology, a key to ♀ plants, and for each species synonymy, typification of names, description, illustrations, and notes on distribution (illustrated by dots maps), ecology, and various other matters. New reductions are proposed of 12 species and 1 variety, and the following new names or combinations are proposed: Pogonatum philippinense (Broth.) Touw, comb. nov. (based on Pseudoracelopus p. Broth.), P. misimense (Bartr.) Touw comb. nov. (based on Pseudoracelopus m. Bartr.), P. iwatsukii Touw, nom. nov. (based on Racelopus acaulis Mitt.), P. petelotii (Thér.) Touw, comb. nov. (based on Pseudoracelopus p. Thér.), P. camusii (Thér.) Touw, comb. nov. (based on Racelopodopsis c. Thér.), and P. piliferum (Dozy & Molk.) Touw, comb. nov. (based on Racelopus pilifer Dozy & Molk.).