Postia stiptica - Bitter Bracket

Taxonomy

Phylum: Basidiomycota

Class: Agaricomycetes

Order: Polyporales

The Bitter Bracket is fairly common but often very well hidden, so that despite being big and brilliant white it is easily missed. Synonyms include Tyromyces stipticus and Oligoporus stipticus (plus at least another dozen!).

The watery droplets that in all but the driest of weather exude from the margin and the pores on the fertile (lower) surface help distinguish this bracket from several other related pallid polypores.

Identification Guide

Cap	Irregular bracket; up to 10cm across; sometimes roughly semicircular but more often shell shaped; 1 to 3cm thick; upper (infertile) surface velvety, uneven; white, becoming light ochre with age; margins rounded in young specimens, more acute as fruitbodies age; lower (fertile) surface with tubes and pores; watery droplets exuded mainly from margin region and from the pores.
Tubes and Pores	The tubes are white and 2 to 6mm deep. Pores are also white and spaced 1 to 2 per mm.
Spore print	White.
Odour/taste	Strong fungal odour; very bitter taste; inedible.
Habitat	Usually on felled trunks and large fallen branches of conifers; very occasionally on the timber of hardwood trees.
Season	Throughout the year, but releasing spores in late autumn.
Occurrence	Fairly frequent.
Similar species	Postia caesia is similar but has a blue tinge and lacks the watery droplets associated with the Bitter Bracket.