Parts of the frond Asplenium trichomanes ssp. quadrivalens.
Asplenium trichomanes ssp. quadrivalens is an evergreen fern with grape-like leaves. Leaves are narrow-lanceolate, 10-25 cm long and 0.7-1.5 cm wide; leaves are pinnate in pairs, ovoid or oblong ovoid, 5-15 mm long, 3-8 mm wide.
Grows on more basic (alkaline) rocks.
Distributed in the temperate zone of the Northern Hemisphere, most often found on limestone rocks.
Asplenium trichomanes ssp. quadrivalens has elongated, leathery frond, crowded at the top of the petiole.
This subspecies naturally grows on moist, shady rocks. It is very decorative and is often grown in rock gardens.