 "Arachniotus ruber" have discrete ascomata present, usually confluent and mostly spherical, measuring 20-200 μm and are red, orange, and brown in colour.Asci of "A. ruber" are ovoid, hyaline, and measure 10-13 x 7-10 μm.The ascospores of "A. ruber" are smooth, spherical, and vary in colour between red, orange, and yellow.