A new species of Comatricha (Myxomycetes) from southern Vietnam

Abstract

A new species Comatricha spinispora Novozh. et D. W. Mitch. was obtained as field collections and isolated from moist-chamber cultures from samples of ground litter. Specimens of sporocarps and substrates for moist chamber cultures were collected in deciduous monsoon tropical lowland forests (Cat Tien National Park, Vinh Cuu Nature Reserve), mixed montane tropical forests and cloudy tropical forests (Bi Dup-Nui Ba Nature Reserve) of southern Vietnam during surveys carried out in December 2010, November 2011, 2012. The morphology of representative specimens of sporocarps was examined by light and scanning electron microscopy and micrographs of relevant details are provided. Spore ornamentation consists of long spines 0.5–0.8 μm long and 6–8 very small additional spines 0.1–0.3 μm long densely distributed over the top part of spine surface and visible only by SEM. The stability of the taxonomic characters of the species was confirmed by several collections obtained over a period of three field seasons in field as well as in moist chamber cultures. Comatricha spinispora resembles C. rutilipedata H. Marx in overall shape and size of the sporocarps but has dark brown bottom of stalk and slightly larger spores decorated by scattered long spines. The main morphological difference between C. spinispora and Macbrideola ovoidea Nann.-Bremek. et Y. Yamam. lies in shape and colour of sporocarp and spore ornamentation.