Mnium hornum
“lipstick thyme moss”
Mnium hornum (pointed leaves) and Plagiomnium cuspidatum (rounded leaf tips) on bluff along stream. Hocking County, Ohio. June 18, 2007.
Mnium hornum on bluff along stream. Hocking County, Ohio. June 18, 2007.
Mnium hornum leaf tip.
How to recognize lipstick thyme moss: Mnium hornum is an acrocarp (cushion moss) with moderately narrow, double-toothed leaves. The leaf cells are equal-sided (isodiametric) cells except along the leaf margins, which are marked by elongate cells. The leaves have a pronounced costa (midrib) that ends well below the leaf apex. All the other species of the double-toothed Mniums found in Ohio have a costa that extends to the leaf tip. Mnium used to be a much larger genus, but it has been divided into Plagiomnium with single teeth along the leaf margin, Rhizomnium without any teeth on the leaf margin, and Mnium with double teeth; the capsule of all of these “Mniums” is drooping. Mnium is pronounced as though there was no “M” in the word.
Where to find lipstick thyme moss: Mnium hornum is an acid-loving moss of moist rocks or soil. In Ohio, it is known from a few northeastern counties and two southern ones.
