Plants generally smaller and more delicate than those of var. norvegica. Leaves 2--6 mm, 0.5--0.6 mm wide at mid-limb; cells of mid-limb lamina 6--10(--11) X 6--9(--10) µm; costa excurrent, smooth on abaxial surface of sheath, smooth or slightly papillose on abaxial surface of the limb, with one–-several teeth at back near the apex; base of costa pale and not strongly attached to the stem; stem tips often with loose deciduous clusters of almost linear leaves (ca. 3 X 0.1--0.2 mm).

Not known with sporophytes, but the deciduous leaves no doubt act as vegetative propagules. In calcareous areas, often on shaded limestone cliffs near rivers in arctic and boreal regions, intermixed with other mosses, including other taxa of Timmia; 0--1500 m; Greenland; Nfld., N.W.T., N.S., Que., Yukon; Alaska; Eurasia (Iceland, Scandinavia, Switzerland, Poland, and Russia).

Timmia norvegica var. excurrens is also known as a Quaternary subfossil from N.Y. and Vt.