It is not rare. Not yet. But the adder's tongue faces increasing pressure from habitat degradation throughout New Zealand forests. This small fern reaches about 10 centimetres in height, with a single sterile leaflet and a fertile spike resembling a tongue. The fronds are coloured bright green, fading to brown as they age. The species inhabits damp shaded areas in native forests throughout New Zealand. It prefers moist fertile soils with high humidity, thriving where rainfall is consistent and drainage is good. Fronds are simple and undivided, unlike most other ferns. Spores are produced on the fertile spike which rises above the sterile leaflet. These spores are released into the air, drifting on wind currents until they land on suitable substrate. Diet consists of nutrients obtained through photosynthesis and absorption from soil via shallow root systems. The fern does not consume organic matter directly but rather extracts minerals and water from surrounding substrate. This autotrophic lifestyle allows it to thrive in nutrient-poor soils where other plants struggle. Classified as Not Threatened, adder's tongue remains widespread throughout New Zealand. Populations are stable in suitable forest habitat. However the species is sensitive to habitat disturbance. When forests are logged or modified, populations decline rapidly. Its presence signals intact mycorrhizal networks and healthy forest ecosystems. Conservation efforts focus on protecting remaining native forests from logging and development to maintain these critical underground connections.