The species epithet refers to the Acadian region of eastern North America, where the lichen seems to be most common.

[2] The thallus, or body, of Leptogium acadiense is foliose, meaning it is leaf-like and loosely attached, and ranges in size from 2 to 9 cm (0.8 to 3.5 in) in diameter.

Apothecia, the reproductive structures of the lichen, are rare, usually stipitate, and range in size from 0.2 to 1.2 mm in diameter.

[2] Leptogium acadiense has a wide distribution across boreal and northern temperate regions in eastern North America.

The lichen prefers deciduous trees like Acer, Aesculus, Fraxinus, and Populus in mixed hardwood-conifer forests but it has also been observed on the bark of conifers like Thuja and on mossy logs or rocks.