Favolaschia calocera - Orange Pore Fungus

Favolaschia calocera's Ascent in Northern Ireland

Bright, bold, and unmistakably exotic, Favolaschia calocera—commonly known as the Orange Porecap—is a newcomer to Northern Ireland’s fungal scene. With its vivid orange hue and distinctive pored underside, this tiny fungus is both a visual delight and a biological curiosity. In this post, we explore its expanding distribution, delve into its spore morphology, and consider its ecological implications.

Distribution

Originally native to Madagascar and tropical Asia, Favolaschia calocera has become a globally invasive species, spreading rapidly across temperate regions. In Northern Ireland, it was first recorded in the early 2020s, likely arriving via imported wood products or horticultural materials.
It now appears in:

•     Urban woodlands and park edges, especially on rotting twigs and branches
•     Nature reserves with high foot traffic, such as Brackagh Bog and Oxford Island
•     Roadside hedgerows and disturbed habitats, where it thrives on small woody debris

Its preferred substrate is dead hardwood, particularly twigs from species like ash, willow, and sycamore. Fruiting occurs from late summer through autumn, though mild winters may extend its season.

The specimen featured here was on a small Sycamore branch, a tree that in itself is non-native too.

Spore Analysis

Despite its flamboyant and tiny appearance, Favolaschia calocera produces microscopic spores that are larger than some of the biggest mushrooms out there.  Here’s a breakdown of its spore features:

Spore showing the spherical shape and distinct size

Spores are produced on the underside pores, which resemble a miniature polypore.  These pores are relatively large for the size of the fruiting body, giving it a honeycomb-like appearance when viewed up close.

The caps are relatively tiny in comparison to other mushrooms related to Mycena genus at only 5-15mm in size.  They can be ridged and bumpy on the cap when observed in close quarters and make a striking image with the colouration and pore layout.

Underside of fungus showing the pores as opposed to gills

Under side of mushroom in detail

The rough tops of the 6-7mm caps

The rapid spread of Favolaschia calocera raises questions about its impact on native fungal communities. Some researchers suggest it may outcompete local saprotrophs, particularly those that colonize small woody debris. However, its long-term ecological role in Northern Ireland remains uncertain as this is a vastly under recorded species here.

For now, it’s a fascinating example of fungal globalisation, and a reminder that even the smallest species can travel far and wide.