Cladonia didyma is a fruticose lichen, commonly known as southern soldiers, belonging to the family Cladoniaceae, which include fungal symbionts under the Ascomycotaphylum with characteristic red ascocarps containing sexually reproductive asci.[2]
Initially named Scyphophorus didymus (Fée 1824), it was later reclassified into Cladoniadidyma in 1887.[3] Its namesake is described as deriving from the ancient Greek κλᾰ́δος (kládos) meaning 'branching' and Δίδυμος (didymus) describing 'bunched', 'clustered' or 'paired'[4] indicative of the branched like structures characteristic of the Cladonia genus and the often observed clusters of C. didyma found among various other Cladonia spp. or other C. didyma variants.[3][5][6]