Nephrolepis arida

Nephrolepidaceae

Nephrolepis arida D.L.Jones

Link to Australian Plant Name Index for publication details and synonyms: https://id.biodiversity.org.au/name/apni/82002

Stolons and basal portions of stipes with scattered lanceolate red-brown scales which sometimes bear marginal cilia. Fronds to 1.7 m long, rachis with moderately dense short simple rust-coloured hairs. Pinnae often with a blunt triangular basal auricle. Sterile pinnae 10–75 mm long, 7–15 mm wide, margins crenate towards round (occasionally acute) apex; underside of pinnae and upper midrib usually covered with short simple hairs, sometimes also with scattered hair-like scales. Fertile pinnae similar to sterile. Sori submarginal, often irregularly spaced, indusium reniform.

Endemic and uncommon in scattered localities in N WA and in central and N NT.

Grows in damp crevices and on ledges in sandstone gorges.

Nephrolepis arida can be distinguished from other Australian Nephrolepis by its shorter, stouter more numerous pinnae with a blunt apex and combined with a lack of basal auricles that overlap the rachis.

Key to Australian Nephrolepis spp.:
1a. Sori linear with a linear indusium and borne on margin; pinnae with entire margins = Nephrolepis acutifolia
1b. Sori round or kidney-shaped with a kidney-shaped indusium and borne supramedially to medially, each on the end of a vein, margins ~ crenate = 2
2a. Pinnae with an obtuse apex, less than 50 mm long = 3
2b. Pinnae with an acute to attenuate apex, greater than 50 mm long = 4
3a. Rachis with scales, rarely hairy, basal auricles of pinnae overlapping rachis = Nephrolepis cordifolia
3b. Rachis with hairs, rarely scaley, basal auricles of pinnae not usually overlapping rachis = Nephrolepis arida
4a. Pinnae with an acroscopic basal auricle; all parts hirsute = 5
4b. Pinnae lacking a distinct acroscopic basal auricle, indumentum sparse = 5
5a. Hairs on upper side of costae absent; rachis scales rufous, with strongly dentate acumen; sori submarginal = Nephrolepis hirsutula
5b. Hairs on upper side of costa present; rachis scales hyaline or light brown (rarely rufous), with nearly entire acumen; sori submedial = Nephrolepis brownii
6a. Sori borne close to margin, stolons densely scaly = Nephrolepis biserrata
6b Sori borne medially, stolons green with few scales = Nephrolepis obliterata