Varietal name honors Tim Flynn, collections manager of the herbarium at the National Tropical Botanical Garden and discoverer of this taxon.
Plants medium-sized, delicate, terrestrial. Rhizomes decumbent, scales sparse, linear-triangular, 5-8 mm long. Fronds drooping, to 60 cm long, very glandular. Stipes glabrous except for few scattered scales at very base, thin, 1-2 mm diam., straw-colored to light brown. Blades 3-to 4-pinnate, finely dissected, linear-triangular, 2-3 x as long as wide, pale green, both surfaces heavily clothed with appressed glands; rachises narrow, mostly 1-1.5 mm diam., straw-colored to brown. Pinnae deltate-elongate, overlapping, heavily clothed with globular adnate glands, multicellular uniseriate hairs scattered on veins. Ultimate segments mostly less than 1.5 mm wide except for distal basal lobes, which are larger, tips rounded to toothed. Sori marginal to submarginal, near tips of segment lobes. Indusia glandular.
Currently known only from plants growing on lower parts of shaded, mossy, wet banks along a few streams, 1,200-2,000 m, near the Pihea Trail in the Koke'e area of Kaua'i.
The name Dryopteris parvula W. J. Rob. has been associated with this taxon in check-lists, but this name belongs in the synonymy for D. glabra var. pusilia.
Dryopteris glabra var. flynnii differs from var. glabra by drooping, linear-trian-gular, very glandular, light green blades that are 2-3 x as long as broad. It also has narrower, glabrous stipes and rachises, and narrower ultimate segments that are mostly less than 1.5 mm wide.