Leaves 15 to 30 cm tall on a creeping rhizome

Oblong to triangular blade (width/length between 1/3 and 1/2)

Sori oval. Sporangia bigger than in P. vulgare, annulus with 6-8 cells.

Can be confused with P. interjectum et P. cambricum (easy to distinguish with a microscope, see References)

The 3 hybrids are known. P x mantoniae (P. vulgare x P. interjectum) can be widespread and sometimes the only one to see (control the spores)

Growth from spring to summer, ripe in autumn to winter, disappearing the next spring

Woods, shaded or sunny slopes, boulders, walls, old trees, up to 1500 m in elevation

Probably widespread in Vercors under 1500 m. It should be interesting to distinguish between P. vulgare, P. interjectum and their hybrid.