Species description:
Genus name meaning split tooth, referring to the forked peri­stome teeth. Species name based on the fancied resemblance of the moss to the fern Adiantum.

Reproduction:
Sporophytes dark brown when ripe, peristome bright red-brown, occasional but, when present, abundant in that population, maturing in spring.

Distinguishing characteristics:
The curious leaves with the unique flap immediately indicate this genus. The species shows pronounced teeth on the leaf margins and the plants tend to be soft with leaf points that curl downward when dry.

Habit:
Forming short to tall turfs of erect to suberect conspicuously flattened, dark green to light green plants.

Similar Species:
F. osmundioides is similar, but is half the size and usu­ally forms very dense turfs; F. grandifrons is of similar size but the plants are aquatic and essentially opaque and very dark green while F. adianthoide leaves are translucent and the plants are not aquatic.

If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

Illustration Source:  Some Common Mosses of BC

Synonyms and Alternate Names:
Fissidens adianthoides var. immarginatus Lindb. ex Lesq. & James