Leucobryum is a genus of haplolepideous mosses (Dicranidae) in the family Leucobryaceae.

[1] Leucobryum species are found in erect, dense, and often rounded cushions.

Species are characterized by having thick, whitish leaves with a large, expanded costa.

[1] It has been suggested that the characteristic pale color exhibited by some species is caused by air bubbles in the leucocysts.

The bubbles are theorized to be necessary for the function of the chlorocysts for the purpose of gas exchange.