Icmadophilaceae species are usually crust-like to shrub-like in form. Their photobiont partner is chlorococcoid, which is crucial for their survival. Their apothecia (fruiiting bodies) are typically biatorine in form, meaning they have a light-coloured (not carbonised) margin, and are often pink in colour. Some may have stalk-like structures, referred to as pseudopodetia.[3]
Within these reproductive structures, Icmadophilaceae lichens have unbranched filaments called paraphyses, which are amyloid. The asci, or spore sacs, in these lichens are thin-walled and lack a thickened top section (apical tholus) but have a thin, amyloid cap at their tips. They are typically cylindrical in shape.[3]
Each ascus typically contains eight spores. These spores come in various shapes – ellipsoid, oblong, fusiform (spindle-shaped), to cutriform (knife-shaped) – and are clear (hyaline) and non-amyloid. In addition to spore reproduction, Icmadophilaceae lichens can also reproduce asexually through structures called pycnidia, which produce rod-shaped (bacillar), hyaline conidia (asexual spores).[3]
In terms of chemical composition, this family is characterised by a variety of depsides, a type of secondary metabolite (lichen product) commonly found in lichens.[3]
