Royal fern; Helecho real

Osmunda regalis is a deciduous fern, growing in woodland bogs and on the banks of streams. Osmunda regalis produces separate fertile and sterile fronds, being the fertile in the interior part of the plant. The sterile fronds are 60–160 cm tall, bipinnate, with 7-9 pairs of pinnae up to 30 cm long, each pinna with 7-13 pairs of pinnules 2.5-6.5 cm long. The fertile fronds are erect and shorter, usually with 2-3 pairs of sterile pinnae at the base, and 7-14 pairs of fertile pinnae above bearing the densely-clustered sporangia, pictures 2 and 3.

It is a typical fern of alder groves, edges of rivers, streams and wetlands developed on acidic substrates, from the sea level to 900 m.

In many areas, O. regalis has become rare as a result of wetland drainage for agriculture.