>species one; trnF(ggc)
GGCCC
AACGC
>species one; rrnS
TAGCA
GGCAC

>species two; trnF(gga)
GGACG
CGACG
GCAC
>species two; rrnS
GCATG
GGCAG

dir/file1:>species one; trnF(ggc)
dir/file1-GGCCC
dir/file1-AACGC
--
dir/file2:>species two; trnF(gga)
dir/file2-GGACG
dir/file2-CGACG
dir/file2-GCAC

$ grep -A 2 'trnF' dir/file*

dir/file1:>species one; trnF(ggc)
dir/file1-GGCCC
dir/file1-AACGC
--
dir/file2:>species two; trnF(gga)
dir/file2-GGACG
dir/file2-CGACG