Rhizome branched, 0.5–2 cm diam., covered with red-brown and silver-grey hairs. Fronds 2–8 cm apart, erect with drooping tips, firm textured, 30–160 cm long. Stipe long, with wide and shallow groove, stiff, straw-coloured but brown and slightly rough towards the thick base, covered in red-brown hairs. Lamina 3–4-pinnate, triangular, often yellow-green, almost glabrous or finely hairy; hairs fine, colourless, denser on lower surface, particularly along veins and rachises. Rachises pale and often mottled with brown, with wide and shallow groove on upper surface. Pinnae subopposite to alternate, shortly stalked, well-spaced along rachis; pinnules deeply lobed, narrow with obliquely decurrent bases (forming green wing along rachis); veins sunken and free, one per lobule. Sori as for family, inner membranous indusium obscure when sorus mature.
GleP, VVP, VRiv, GipP, OtP, WaP, Gold, CVU, GGr, NIS, EGL, EGU, WPro, HSF, HNF, OtR, Strz, MonT, HFE, VAlp. Also Qld, NSW, Tas. Found in rainforest, open eucalypt forest or in sheltered, open areas where large, almost pure stands can be formed.
The curled tips of developing fronds are bright green and covered in fine, colourless to fawn hairs. Developing frond tips of Pteridium esculentum, which can grow together with C. dubia, are red-brown due to a covering of coloured hairs. In both species, the young coiled frond is coarse and fleshy. In a few populations of C. dubia the stipes are quite reddened and the fronds dark green; fertile fronds should be examined to distinguish such populations from Dennstaedtia davallioides. Until recently, this fern was widely known as Culcita dubia. The subgenus Calochlaena of Culcita, which included C. dubia, has been now raised to generic rank based on a range of features including shoot anatomy, soral and spore morphology and chromosome numbers.
