Hydnangium aurantiacum

A hypogeous to semi-hypogeous fungus that emerges noticeably onto the soil surface during late developmental stages. Its striking coloration, ranging from deep orange to paler hues with yellowish or whitish mottling, makes it almost unmistakable. Stephanospora caroticolor has similar coloration, but its gleba is smoother and lacks the tuberiform, irregular morphology of H. aurantiacum; furthermore, microscopy readily separates them.

We find it year after year fruiting in large numbers on bare ground within a plantation of Cupressus sempervirens, typically from November to early February. A rare species with very few literature records, which appears in dense gregarious troops where established.

The microscopy corresponds to a collection gathered in December 2019 under Cupressus sempervirens in Amurrio (Álava), with subsequent photographs illustrating later collections.