Rhizomes long-creeping. Fronds of indefinite length, branches divided 2-3 times. Segments tapering and extending down the midrib, not articulated; veins free. Sori in marginal 'spikes'.
Needs shelter and warmth.
N Australia, China, Japan, Korea to India.
This species is sometimes confused with L. flexuosum (L.) Sw.
Lygodium japonicum has fronds mostly 5 mm or more apart on a long-creeping rhizome and fertile secondary branches mostly divided 3 times.
L. flexuosum has the stalks attached close together on a short-creeping rhizome; the fertile secondary branches are mostly divided twice.
Lygodium microphyllum (Cav.) R. Br., Climbing Maidenhair or Snake Fern, from the tropics, is occasionally cultivated and distinguished by the mostly ovate sterile and fertile segments.
Source: (1995). Schizaeaceae. In: . Horticultural Flora of South-eastern Australia. Volume 1, Ferns, conifers & their allies. The identification of garden and cultivated plants. University of New South Wales Press.