Plants tightly attached to substrate. Stems stoloniferous. Stem leaves slightly reflexed when moist, 0.5–1 × 0.3–0.4 mm. Seta 0.4–0.7 cm. Capsule exserted, dark brown, 0.7–1 mm; exostome teeth smooth proximally, papillose distally; endostome rudimentary. Spores 12–30 µm.
Habitat: Trees, rock
Elevation: low to moderate elevations
B.C., Alaska, Oreg., Wash., e Europe, e Asia (China, Japan, North Korea, Russian Far East).
In Oregon and Washington, Iwatsukiella leucotricha occurs on trees along fog-drenched coastal ridges. Collections from British Columbia were made from trees in coastal bogs and swamps; this species has also been collected on rock in Alaska.