Nigrohydnum is a fungal genus in the order Polyporales. It contain a single species, Nigrohydnum nigrum, a rare toothed polypore known from only a few collections in Brazil.
The fruit body of the fungus is characterized by its purplish-black, semicircular caps with spines on the cap underside. The caps, which measure up to 3 cm (1.2 in) wide by 5 cm (2 in) broad and 1 cm (0.4 in) thick at the base, become tough and woody when dried. The spines on the cap underside are up to 3 mm long, and are densely packed, numbering about 1–3 per millimetre. Nigrohydnum has a dimitic hyphal system, containing both generative hyphae with clamp connections and skeletal hyphae. The spores of Nigrohydnum nigrum are cylindrical, thin-walled, hyaline, and measure 4.5–2 μm. They are inamyloid.[1]
The type of the fungus was collected in Serra do Aracá State Park, in the state of Amazonas, Brazil.[1] It was later reported from Paraná.[2] After an old voucher specimen was discovered in a herbarium and identified to be N. nigrum, the geographic distribution was extended to the Atlantic rainforest of Porto Alegre, Rio Grande do Sul state, in Southern Brazil.[3]
Nigrohydnum is a fungal genus in the order Polyporales. It contain a single species, Nigrohydnum nigrum, a rare toothed polypore known from only a few collections in Brazil.
