Rhizome 1 mm thick (or less), internodes to 0.5-1.2 cm long; vascular strands with bundle sheath hyaline or partially sclerified; sclerenchyma strands many. Rhizome scales peltate, spreading, 3-5 by 0.3-1 mm, acute, straw-coloured to brown, evenly coloured, entire. Fronds simple, dimorphic. Fertile fronds with stipe 0.3-4 cm long; lamina 1.5-7 by 0.3-1.2 cm, index 2.1-8.8, widest at 0.3-0.5 from base (sometimes linear); base narrowed, apex acute or sometimes acuminate. Sterile fronds with stipe 0.1-3.5 cm long; lamina 0.6-2.7 by 0.5-1.5 cm, index 0.9-4, widest at 0.2-0.5 from base; base often truncate, apex obtuse or rounded. Venation: costa only distinct or (occasionally) veins distinct, raised on upper surface; veinlets nearly all free, excurrent and recurrent. Hydathodes frequent (rarely absent in small specimens), calcareous scales not persistent. Margin cartilaginous, flat, usually somewhat incurved; notches regularly present. Sori round, two between adjacent veins (often one in small fronds), in one row between costa and margin (sometimes a few in a second row in large fronds), 2 mm wide, slightly sunken.
Home