Psilachnum rubrotinctum

Very small fruit bodies consist of a greyish white fertile upper surface and pale yellowish white exteriors, which become a dull yellow colour when dry. Their margins have short, hyaline hairs. They have very short stalks. When exposed to ammonia vapour, the fruit bodies turn a brick red or orange colour. 

microscopy/ammonia test

Photograph on host plant; note substrate and associated plant species.  We recommend that this is identifed by an expert, from a specimen, before submission to NatureSpot; microscopic examination and/or ammonia test may be needed

Their hosts include damp, dead stems of meadowsweet and willow herbs.