Ebony spleenwort, Asplenium platyneuron  

Ebony Spleenwort is a  small, graceful, evergreen fern that grows in a small clump from its rhizome  This species' common name is derived from its dark, shiny stem.  Some Canadian Provinces and U.S. states consider this plant a vulnerable or endangered species.  In its native conditions, it grows in a broad range of habitats such as rocky banks and outcrops, disturbed sites, fields, and wooded slopes.  It supposedly grows best in well-drained rocky soils (although no one explained that to this fern as it grows very well in moist woodlands,) in shade to part sun, with dry to medium moisture. 

 Its dimorphic fronds characterize it.  Sterile evergreen fronds are lighter green, glossy, slightly arching, or may lay close to or flat on the ground. Fertile deciduous fronds are erect, dark green, and die off in the winter.  A central stem (stipe) is dark purple-brown.  Ebony Spleenwort reproduces by spores and also propagates vegetatively, forming buds near the base of the stem on either sterile or fertile fronds.  Pale button-like buds appear on the upper side of the lowest leaflets.  When buds fall off and make contact with soil, or get covered with woodland leaf litter, growth is stimulated and they produce new ferns as the parent plant dies off.  

It is not particularly sensitive to pH but prefers acidic conditions with pH 4.5-5.  It is easy to grow and suitable for woodland or native plant gardens in dry, rocky, shady crevices.  (Currently, I am experimenting with growing a few as Kokedama with more or less success).