European royal fern

Royal fern is a large perennial herb with stout ascending rhizomes that over many years build up a woody, trunk-like base covered by interwoven roots, 1 m or more high. The fronds, or leaves, arise directly from this rhizome and are very large, typically up to 120 cm but exceptionally as much as 400 cm long and 30-40 cm broad. Each frond is bipinnate, with 5–9 pairs of pinnae up to 30 cm (12 in) long, each pinna with 7–13 pairs of pinnules 2.5–6.5 cm (0.98–2.56 in) long and 1–2 cm (0.39–0.79 in) broad. Many of the fronds have a terminal fertile portion, where the blade is reduced almost to the midrib and densely covered with brown sporangia. The fronds are at first covered with golden-brown hairs which quickly disappear, leaving a smooth, pale green surface to the leaves. Veins are prominent on both surfaces.

In the gametophyte stage, the prothallus is a small, green, fleshy plant just a few millimetres in size.

The native range of royal fern is throughout Europe, North Africa and the Middle East as far as Iran, from Norway south to Algeria. It is listed as introduced in New Zealand, but its presence throughout North America is based on the taxonomic uncertainty about whether Osmunda spectabilis should be considered a separate species or not. In many areas, O. regalis has become rare as a result of wetland drainage for agriculture.

The roots, along with those of other species of Osmunda, are used for the production of osmunda fibre, used as a growing medium for cultivated orchids and other epiphytic plants. According to Slavic mythology, the sporangia, called "Perun's flowers", have assorted magical powers, such as giving their holders the ability to defeat demons, fulfill wishes, unlock secrets, and understand the language of trees. However, collecting the sporangia is a difficult and frightening process. In earlier traditions, they must be collected on Kupala Night; later, after the arrival of Christianity, the date is changed to Easter eve. Either way, the person wanting to collect Perun's flowers must stand within a circle drawn around the plant and withstand the taunting or threats of demons. The young shoots of the fern are, along with the similar shoots of many other fern species, known in some places as fiddleheads, and eaten as food, thought to have an asparagus-like taste.

Osmunda regalis is widely cultivated in temperate regions. The species and the cultivar 'Cristata' have both gained the Royal Horticultural Society's Award of Garden Merit. Osmunda plants should be planted in preferably acidic, moist soil, associating well with other large moisture-loving plants such as Rodgersia and Gunnera. However, it tolerates a range of soil and climatic conditions.