Asplenium fontanum (L.) Bernhardi

Smooth spleenwort

Etymology Fontanum means growing in running waters.
Description Rhizome: erect, short, scales clathrate, brown, lanceolate, to 4 mm.
Frond: 15 cm high by 5 cm wide, evergreen, monomorphic, blade/stipe ratio: 3:1.
Stipe: blackish at base for 2 cm or less, then green above, brown scales at base, becoming hair-like above, then the rachis almost glabrous, vascular bundles: 2 C-shaped, back to back, uniting to 1 upwards to an X-shape.
Blade: 2-pinnate-pinnatifid, lanceolate, widest above the middle of the blade, light green to gray-green, herbaceous, glabrous.
Pinnae: 10 to 20 pair, alternate, anadromic, basal pinnae more distant; pinnules up to 5 pair at the widest part of the frond, diminishing to 2 at the base; margins coarsely incised; veins free, forking.
Sori: linear, along a vein, indusium: whitish, entire, opening outwards, sporangia: dark brown, covering the segments at maturity.
Culture Habitat: calcareous rocks in relatively dry situations. Distribution: central Europe, Himalayas. Hardy to -25°C, USDA Zone 5.
Distinctive Characteristics A small, lacy, narrow-bladed, elegant Asplenium with smaller pinnae at the base than the middle.
Asplenium fontanum
Asplenium fontanum.  Juan Bibiloni on Wikimedia Commons
Compare to The only other 2-pinnate-pinnatifid spleenwort listed here is A. adiantum-nigrum, which is broadest at the base vs. broadest above the middle.
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