Austroblechnum bullatum

Rupicolous or epiphytic plants; rhizomes short, decumbent to erect, 3 cm long, 3 – 4 mm in diameter, stoloniferous; scales 6 × 1.2 mm, ovate-lanceolate, apex acuminate, basifixed, lustrous, light brown to dark brown, sometimes with sclerotized lines. Leaves dimorphic. Sterile leaves 29 – 34 (– 40) cm long; petioles 11 – 16 (– 19.5) cm long, 1 – 15 mm in diameter, sulcate, atropurpureous, generally stramineous towards the apex, sometimes stramineous in the upper 2 / 3, base scarcely covered with scales similar to those of the rhizome; petioles sometimes abaxially and towards the apex covered with simple hairs, scattered, straight to undulate, long and short, from 0.1 to 0.5 mm long, dark brown, 3 meristeles in cross section; laminae 20 – 27 × 4.5 – 5.5 (– 7.5) cm, pendulous, pinnatisect, narrowly elliptic, abruptly reduced at the base to 1 – 2 pairs of semicircular to triangular pinnae, 0.7 – 1 × 0.2 – 0.5 (– 0.7) cm; rachises adaxially sulcate and glabrous, abaxially covered with abundant simple, straight to tortuous, dark brown hairs, 1 – 2 (– 2.5) mm long, 5 – 12 celled, shorter towards the apex of the laminae; buds absent, aerophores absent, pinnae 23 – 24 (– 29) pairs, 2.5 – 3 (– 4) × 0.7 – 1 cm, falcate, bullate on both surfaces, acute apex, connate 0.5 – 1 mm, entire margins, glabrous or with sparse hairs similar to those on the rachis, located marginally and along the two proximal thirds of the costae on the abaxial side, abaxial epidermis with very short; terminal pinnae bases lobulate to crenate, with acute to largely acuminate apex; veins free, furcate, simple towards the pinna apex, with claviform ending and adaxial hydathodes. Fertile leaves shorter than sterile ones, (23 –) 27 – 33 cm long; petioles 13.5 – 15 (– 18) cm long, 1 – 1.5 mm in diameter, sulcate, atropurpureous to brown and with stramineous apex, base covered scarcely with scales similar to those on the rhizome; laminae (10 –) 14 – 19 × (2.5 –) 4 – 5 cm, erect, pinnate, elliptic, abruptly reduced on its base to 2 – 3 pairs of semicircular pinnae, 0.3 – 0.6 × 0.1 – 0.2 cm; rachises adaxially sulcate, covered with spaced, simple, straight to tortuous hairs, 0.3 – 0.5 (– 1) mm long 3 – to 4 celled, atropurpureous to stramineous; pinnae 22 – 27 pairs, linear, largest ones 30 – 35 × 10 – 15 mm, with bases widened to 2.5 – 3.5 (– 4) mm. Sori and indusia following shape of pinnae, one on each side of the costa; indusia introrse, 1 – 2 mm wide, entire to erose when mature. Spores monolete, ellipsoid, dark brown.