Leptecophylla mariannensis is a plant in the Ericaceae family (heath or heathers) and is only known to exist on the tiny island of Alamagan in the Mariana archipelago.

[1] The species was first collected in 1933 by Japanese botanist, Ryōzō Kanehira, who described it in 1934 as Cyathodes mariannensis in The Botanical Magazine (Tokyo) (植物學雜誌, Shokubutsugaku zasshi).

An isotype fragment, also collected in 1933, was named Styphelia mariannensis, and reportedly found in mossy thickets and open places up to 700 meters elevation.

[4][5][6] It was not recorded during the 2017 botanical survey of Alamagan by the CNMI Division of Fish & WIldlife.

However, a detailed examination and descriptive treatment of Leptecophylla mariannensis was not provided by the author.