Rhytidiadelphus japonicus

(Reimers) T. J. Koponen

Hikobia 6: 19. 1971

Basionyms: Rhytidiadelphus squarrosus subsp. japonicus Reimers Bot. Jahrb. Syst. 64: 559. 1931
Treatment appears in FNA Volume 28. Treatment on page 332. Mentioned on page 331.
Plants to 7 cm, soft. Stems 3–5 mm wide across leafy stem, remotely and irregularly branched to irregularly 1 (or 2)-pinnate, branches to 1.5 cm. Stem leaves wide-spreading to squarrose, not crowded, broadly ovate, not plicate or rugose, 2.1–3.8 × 1.6–3.2 mm; base scarcely sheathing, broadly rounded to insertion; apex abruptly narrowed, acumen short, channeled; costa 1/3–1/2 leaf length; alar cells vaguely distinct, slightly wider than basal cells, walls thick, porose; medial laminal cells 25–55 × 4–7 µm, smooth. Branch leaves ovate, 1.5–2.8 × 0.7–2 mm. [Capsule oblong, 2.1 mm].

Habitat: Under tall forbs in coastal meadows of lower mountain slopes
Elevation: low elevations (0-30 m)


Rhytidiadelphus japonicus is known from five or fewer localities in North America, all in the Aleutian Islands.

Selected References


Lower Taxa