The species was described as new to science by the lichenologists Kerry Knudsen, John A. Elix, and James Lendemer in 2007; it was originally classified in the genus Lepraria.

It was found in a thin-soiled opening in maritime chaparral on sandstone bluffs, growing over Rinodina intermedia, Lepraria xerophila, bryophytes, and soil.

[3] Lendemer and Brendan Hodkinson transferred the species to the genus Leprocaulon in 2013 as part of a major revision of the classification of leprose lichens.

A distinctive feature of this species is the presence of small attaching hyphae that act as anchors or rhizines, causing the granules (soredia) to adhere to one another and to the surface they grow on.

[5] While Leprocaulon adhaerens is rarely found with apothecia (fruiting bodies), a fertile specimen was documented in San Benito County, California.

[5] It has been recorded in coastal southern California, from the Santa Monica Mountains south to San Diego, as well as in scattered locations in Pennsylvania and Missouri.