Chaenotheca is a genus of lichenized fungi within the family Coniocybaceae.[1] The sexual reproduction structures are a mass of loose ascospores that are enclosed by a cup shaped exciple sitting on top of a tiny stalk, having the appearance of a dressmaker's pin (called a mazaedium), hence the common name pin lichen.[2]: 15 Genus members are also commonly called needle lichens.[3] Photobiont partners for Chaenotheca include members of the algae genera Symbiochloris, Trebouxia, Trentepohlia, and Tritostichococcus.[4]