Nephrolepis cordifolia

Nephrolepidaceae

Nephrolepis cordifolia (L.) C.Presl

Link to Australian Plant Name Index for publication details and synonyms: https://id.biodiversity.org.au/name/apni/82033

Sword Fern or Fishbone Fern

Stolons often producing spherical tubers to 15 mm diam.; stolons, tubers and basal portions of stipes densely covered with linear-lanceolate brown scales with short basal processes and denticulate margins. Fronds to 1 m long (rarely longer); rachis bearing scales consisting of a round dark base giving rise to 1 longer and many shorter hair-like processes. Pinnae usually glabrous, with an enlarged rounded basal auricle overlapping the rachis. Sterile pinnae 12–35 mm long, 6–11 mm wide; margins crenulate towards the rounded apex. Fertile pinnae often shorter, with crenate margins. Sori submarginal, usually in very regular rows with open side of reniform indusium oriented towards pinna apex. 

Occurs along the NE QLD coast and hinterland from Cooktown south to northern NSW and in WA and NT. Also widespread in the palaeotropics.

Terrestrial, lithophytic and occasionally epiphytic in rainforest and rainforest margins in a wide variety of situations.

Both indigenous and naturalised populations of this species occur in QLD.

Easily cultivated in a the ground or in a handing container in a tropical, subtropical or warm temperate garden or fernery.

Nephrolepis cordifolia can be distinguished from other Australian Nephrolepis by its shorter, stouter more numerous pinnae with a blunt apex combined with basal auricles that overlap the rachis. It sometimes has sphaerical tubers on the root system.

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