THALLUS yellow-brownish, 320-700 µm.
RECEPTACLE (r) axis below the perithecium, 180-460 µm long, straight, consisting of 13-27 isodiametric or slightly flattened cells (receptacle stalk cells; rsc), slightly increasing distally; short proliferating posterior branch consisting of flattened, decreasing cells is developed as a continuation of the main receptacle axis above the stalk of the perithecium.
APPENDAGES dark brown, of three types, a, b, and c.
Appendages of type a (appa) formed in the lower part of the receptacle, broken off early.
Appendages of type b (appb) abundant in the middle and upper part of the receptacle axis, around the base of the perithecium and on the proliferating branch; in the lower part of the thallus, the appendages are short, 3-celled, whereas in the upper part of the thallus they are longer (up to 100 µm), 3-4-celled, all with a long first cell (above the basal septum) and a rounded distal cell.
Appendages of type c (appc) numerous, formed anteriorly along the main axis and in a posterior group below the perithecium, 40-50 µm long; the axis of the c appendages with the distal cell bent downwards.
PERITHECIA (p) 160-225 x 45-65 µm, with an inflated venter and a slightly differentiated neck terminated in a rounded apex; occasionally, a second perithecium forms above the primary one.
Stalk cell of perithecium (scp) usually slightly elongated, with a flattened basal cell.
SPORES hyaline, 50-58 x 4-5 µm.
HOST AND DISTRIBUTION. The specimens of R. philonthinus presented here are from Philonthus varians (Paykull) (Staphylynidae). It has also been found associated with some other genera of the Staphylynidae (Majewski 1994).
According to Majewski (1994), apart from Poland, R. philonthinus also commonly occurred in East Asia, other regions of Europe, Africa, and North America.
Majewski T. 1994. The Laboulbeniales of Poland. Polish Bot. Stud. 7, 3-466.