1. Asplenium bradleyi D.C. Eaton (Bradley's spleenwort)
Pl. 1g,h; Map 1
Leaves 3–25 cm long, monomorphic. Petioles reddish brown to black their entire
length, shiny, the color extending through 1/2–3/4 of the rachis. Leaf blades
1–2 times pinnately compound, linear to lanceolate or narrowly triangular in
outline. Pinnae mostly alternate on the rachis, 6–25 mm long, ovate or
triangular to lanceolate, the lower pinnae compound or deeply lobed, at least
toward the base of the leaf blade, the bases often overlapping the rachis.
Veins not anastomosing. Spores 64 per sporangium. 2n=144.
Scattered throughout the Ozark and Ozark Border Divisions, locally west to Vernon County
and north to Montgomery County (eastern U.S.
discontinuously west to Oklahoma).
Sheltered ledges of sandstone, chert, and granite bluffs.
Asplenium bradleyi is a fertile, tetraploid taxon that originated from a
cross between the diploids, A. montanum and A. platyneuron. As
such, its variable morphology combines features of the two progenitors. Leaf
size and division are quite variable in Bradley's spleenwort.
For discussion of the sterile hybrid with A. pinnatifidum, see the
treatment of that species. Asplenium bradleyi also has been documented
to backcross to form sterile, triploid hybrids with A. montanum and A.
platyneuron, but these have not been reported yet for Missouri.