Pteris argyraea T. Moore, Gard. Chron. 1859: 671 1859. (syn: Pteris confusa G.Walker; Pteris quadriaurita var. argentea Bedd.);
. India, Sri Lanka, Sumatera as per POWO; .
India (Maharashtra, Andhra Pradesh, Karnataka, Kerala, Madhya Pradesh, Odisha, Tamil Nadu), Sri Lanka, Sumatra, ?Java as per Catalogue of Life;
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Terrestrial herb with erect rhizome, 1.5-2 x 2-3 cm, erect. Scales 0.4 x 0.5 mm, linear-lanceolate, dark in the middle, pale brown along the margin, fimbriate. Fronds 4-50 x 20-30 cm; stipe 20-30 cm long, scaly below, glabrous, glossy above; lamina 25-30 x 20-30 cm, bipinnate, 3-5 pairs, lanceolate in outline, 10-15 x 3-4 cm, with a prominent white band along the costa on the upper side, margins deeply lobed; lobes 0.5-2.8 x 0.5-0.8 cm, oblong, sub curved to apex, obtuse, veins free; basal pinnae bipartite, terminal pinnae single, 1-2 x 0.2-0.4 cm, lanceolate acuminate. Sporangial capsule 350-400 x 375 µm, capsule subglobose or globose with stalk of 375 µm long. Spores 40 x 38 µm, dark brown, triangular in outline, thickly reticulate. Semi-evergreen and evergreen forests
Fern herbarium specimen SN12420 : 3 posts by 2 authors. Attachments (1) – 3 mb. No, sorry, it id not at all Pteris quadriaurita, which is uncertainly known from India, but is in Sri Lanka. You can see the sinus between the pinna-lobes is not cut right down to the costa as it is in P. quadriaurita, and the pinna-lobes are not toothed as in quadriaurita. Sori in all Pteris are at the margins beneath.
But for this group it is good you showed the top surface. As you can see there seems to be a pale central strip along each pinna (paler along the pinna-costa and lobe-bases, so I assume it is P. argyrea. The stripe is not very prominent so is a bit towards the P. confusa form of argyrea (I think both are conspecific).
But that feature varies continuously from bright white to vaguer or to all green – it is not of taxonomic importance.
. References: Clarification of the typification of Pteris argyraea (Pteridaceae)– Piu Das and others- Phytotaxa 269(1):59 · July 2016 (Abstract- Pteris argyraea Moore (1859: 671), commonly known as silver brake fern, is originally a south-east Asian species, but now cultivated as an ornamental plant throughout the tropical regions of the world.)
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