Collema nigrescens is a leafy (foliose) jelly lichen (Collema genus) found growing on the bark of trees such as bigleaf maples, in wetter coastal parts of California.:34, 36 It is commonly called button jelly lichen or bat's wing lichen.:34, 36 It is blackish-green when wet, and dark brownish-green to dark olive when dry.:34, 36 The photosyntheic partner is the Nostoc cyanobacterium that is spread throughout the thallus (main body part).:34, 36 Although foliose