OTA 057306

Fruiting body a stalked sporangium, gregarious, stalked, up to 2 mm tall. Sporotheca subglobose, shiny, scarlet fading to orange, about 1 mm in diameter. Hypothallus membranous, discoid or contiguous for a group of sporangia, brown. Stalk sturdy, 0.2–1.2 mm long, pale orange, filled with white, crystalline lime. Peridium of three closely adherent layers, the outer layer membranous, bright yellow, the middle layer calcareous, thick and brittle, the inner layer membranous, colourless and smooth, dehiscence from the apex, forming 6–8 lobes and thus more or less floriform. Columella conical or globose, calcareous, reaching to about the centre of the sporotheca, pale yellow. Capillitium dense, the threads rather slender, very pale orange. Spores dark brown in mass, medium dark violet-brown by transmitted light, subglobose, warted, 10–15 µm in diameter. Plasmodium unknown.

Described originally from South America (Nannenga-Bremekamp 1989), this species also has been reported from several localities in southern Mexico (Rodríguez Palma 1998). The New Zealand record is based upon a specimen collected in Dunedin.

Various types of plant debris

Nannenga-Bremekamp (1989).

The collection from New Zealand, which consists of approximately 25 sporangia, was referred to Diderma miniatum only because it seems to fit the published description of this species better than any other member of the genus Diderma. The identification is not entirely satisfactory, since the New Zealand material also differs in several important respects. For example, the colour of the peridium is yellow instead of the "scarlet fading to orange" mentioned in the original description, the spores are larger (up to 15 µm in diameter versus 10–11 µm in diameter), and the columella is globose and not conical. Because D. miniatum is an apparently very rare species represented by only a few collections, the total extent of its morphological variation is still unknown. Further study with adequate material may indicate that the collection from New Zealand is a separate and distinct species, but it is included within D. miniatum for the purposes of this monograph.