DIVERSITY IN CRYSTAL PRODUCTION BY SOME BIRDS NEST FUNGI (NIDULARIACEAE) IN CULTURE

Hyphae of many species of bird's nest fungi (Nidulariaceae) were exami ned for the presence of crystals. Scanning electron microscopy reveale d crystals typical of calcium oxalate associated with hyphae. Crystal depositions included complete hyphal encrustation, organized druses, r andomly arranged groups, single crystals, and relatively ''clean'' hyp hae. The majority of crystals could be morphologically classified as s tyloid, raphide, or bipyramidal type. Energy-dispersive X-ray microana lyses confirmed that all crystal types were rich in calcium, and X-ray diffraction identified both the dihydrate (weddellite) and monohydrat e (whewellite) forms of calcium oxalate. Morphological variation of cr ystals was species and medium specific, with generally more crystals b eing produced on relatively calcium-rich V8 juice agar than on PDA. No association was found between crystal types and geographic and habita t distribution of species.