Notes
Compare to D. filix-mas and D. oreades. C.N. Page writes "The more generally shining frond which is more yellow green on flushing, the denser, generally more golden-brown scales ..., the stiffer, more leathery frond texture, the narrow pinnae with usually more truncated segments, the laxer crozier when flushing, and the dark patch to the base of each pinna distinguish most specimens of all subspecies of D. affinis from both D. filix-mas and D. oreades, the only other species with which they are likely to be confused."
Progeny All D. affinis are apogamous, i.e., the offspring are identical to the parent plant, hence, no variation except for the occasional mutations that have given rise to all the cultivars.
ssp. borreri frond/stipe ratio 2:1, i.e., a longer stipe than ssp affinis, stipe scales straw to pale gray-brown rather than golden-brown. The dark blotch at the junction of rachis and costa is mentioned as true for the species, but shows up in none of the subspecies images above.
ssp. cambrensis blade longer, narrower, lower pinnae gradually shorter, the lowest half the middle, pinnules of uneven length, often twisted, often with margins folded down, scales reddish-golden, glossy, twisted on the upper stipe. This taxon may include parentage from D. oreades or D. caucasica or both.