Lignosus sacer

Lignosus sacer is a woody polypore of the family Polyporaceae and a member of the genus Lignosus, the group collectively known as tiger milk mushrooms. Unlike a typical fleshy mushroom, its medicinal value lies in a hardened underground sclerotium rather than the bracket-like fruiting body. L. sacer is the African representative of the genus, found in tropical forests of Africa, and is distinguished from its relatives chiefly by microscopic features such as pore size and spore dimensions.

History

The tiger milk mushrooms take their name from Lac tigridis ('tiger's milk'), a term recorded in 17th-century European writings describing a prized, metal-heavy 'concretion' brought from Asia that physicians of the day could not identify. The most famous and best-studied member of the genus is the Southeast Asian Lignosus rhinocerus, long used by Indigenous communities as a tonic and remedy. L. sacer shares this ethnomycological heritage within the genus but is the African species, named from the Latin lignosus ('woody') and sacer ('sacred'); it remains far less studied than its Asian relative, and much of its biology and phylogeny is still poorly documented.

Overview

Lignosus species are regarded among the most valued medicinal fungi where they occur, and the genus is traditionally used as a general tonic and for immune enhancement and a range of ailments including cancer, asthma, sinusitis, bronchitis, nausea and allergic reactions. The sclerotium is the source of this medicinal value. L. sacer itself is not a culinary mushroom and is too tough and woody to eat. Because most pharmacological research has focused on L. rhinocerus, species-specific data for L. sacer is limited, and wild specimens have been reported to carry trace levels of toxic metals - reasons to treat any consumption cautiously and to rely on properly identified, tested material.