Telmatoblechnum indicum

Blechnaceae

Telmatoblechnum indicum (Burm.f.) Perrie, D.J.Ohlsen & Brownsey

Link to Australian Plant Name Index for publication details and synonyms: https://id.biodiversity.org.au/name/apni/248818

Swamp Fern

Rhizome short-creeping to erect. Sterile and fertile fronds similar, 23–50 (–200) cm long, 6–15 (–28) cm wide. Stipe 6–83 cm long, stramineous to brown, darker at base; scales lanceolate, acuminate, entire, reddish brown to bicolorous. Lamina ovate to lanceolate, pinnate, with 17–52 pairs of pinnae; rachis and costae stramineous to brown; rachis glabrous; costal scales small, triangular, entire, reddish brown; sterile pinnae oblong-lanceolate, acuminate, 4–16.5 cm long, 5–16 mm wide, sessile, closely spaced; margins serrate; basal pinnae similar or slightly shorter; fertile pinnae similar to sterile. Spores 34 × 25 µm; perine granulose; exine smooth. 

Widespread along the northern and eastern coasts and hinterland from Arnhem Land NT to northern NSW. Also in Asia, Malesia and Pacific Islands.

Terrestrial in swamps, soaks and near creeks. This species usually occurs in open forests in sunlit areas but also occurs in closed canopy swamp forests.

An attractive ornamental fern used in pot and ground cultivation in wet areas.

Best grown in very bright light to full sun in a moist area of the garden in tropical or subtropical areas. If grown in a container it may need to be placed in a basin of water in hot weather.

Occasionally confused with Telmatoblechnum serrulatum from the Neotropics. Sterile pinnae of T. indicum are not distinctly discolorous (cf. distinctly discolorous in T. serrulatum) and taper for most of their length (cf. shortly acute apex in T. serrulatum).