Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Notes: Superficially Leptochidium is similar to large species of Leptogium and Collema, both of which contain Nostoc as the photobiont. Collema does not have either an upper or lower cortex. Leptochidium is the only genus of the three to have white hairs on the upper surface, although one group of Leptogium species (sect. Mallodium) has either very short, white hairs or white tomentum on the lower surface and occasionally the margins (e.g. L. hirsutum).