Two species in the region.
Powder-green thallii with nearly black scales on the undersurface, the sporangium sheathed by a glossy, purple black keeled envelope at the apex of the dorsal surface of the thallus. The thalli, when dry, have incurved margins, and form black strands creeping on the substratum.
Habitat: Somewhat shaded fine-textured mineral soil on outcrop ledges in the northern part of its range, and in California abundant on shaded banks of the oak woodland and chaparral.
Reproduction: Sporophytes frequent in Spring.
Local Distribution: From the southwestern portion of British Columbia mainly near the coast, and southward to southern California, where it is often abundant.
World Distribution: Widely distributed in warm temperate to tropical parts of the world.
Distinguishing Characteristics: The powdery green thalli with dark purple ventral scales and the immersed sporophyte on the ventral surface at the thallus apex are usually enough to separate this genus. Fortunately, sporophytes are usually present.
Similar Genera: When bearing sporophytes, no other local genus can be mistaken for Targionia. Sterile specimens of Mannia are similar in colour, but the thallus tends to be very elongate and strongly incurved to wormlike when dry, and never so in Targionia.
Source: Extracted with permission from Field Guide to the Liverwort Genera of Pacific North America (Schofield 2002).