Surface wax, structure and function in leaves of Polytrichaceae

Abstract

Abstract The form and distribution of epicuticular wax has been examined by SEM in 35 species of Polytrichaceae. Australian and New Zealand species of Dawsonia have a dense covering of prominent angular platelets (or more irregular wax) on the lamella-margins; Polytrichadelphus magellanicus is very similar. In Polytrichum the epicuticular wax forms an angular to rounded granularity which varies in quantity from species to species; abundant and prominent on the lamella-margins of, e.g., P. formosum and P. commune, hardly detectable in, e.g., P. sexangulare. Pogonatum spp. show sparse to dense angular to rounded granularity on both surfaces, generally more abundant on the upper surface but (with the exceptions of P. grandifolium and (especially) P. urnigerum) less differentiated on the lamella-margins than in Dawsonia or Polytrichum. The parallel between Polytrichum alpinum, Pogonatum grandifolium, P. urnigerum, Psilopilum australe and P. crispulum is noteworthy. Oligotrichum, Batramiopsis, Atrichum and the...