Osmunda regalis, or royal fern,
Description
Royal fern is a large perennial
Herbaceous plant with stout ascending
that over many years build up a woody, trunk-like base covered by interwoven roots, 1 m or more high. The
, 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 long, each pinna with 7–13 pairs of pinnules long and broad. Many of the fronds have a terminal fertile portion, where the blade is reduced almost to the midrib and densely covered with brown
sporangium.
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.
Distribution and status
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.
Taxonomy
The name
Osmunda possibly derives from
Osmunder, a Saxon name for the god Thor.
The name "royal fern" derives from its being one of the largest and most imposing European ferns. The name has been qualified as "old world royal fern" in some American literature to distinguish it from the closely related American royal fern,
O. spectabilis. However this terminology is not found in British literature.
Evolution
The oldest known fossils of
Osmunda date to the
Paleocene,
Osmunda likely derives from fossil species currently assigned to
Claytosmunda.
Varieties
There are three to four varieties as traditionally construed:
-
Osmunda regalis var. regalis. Europe, Africa, southwest Asia. Sterile fronds to 160 cm tall.
-
Osmunda regalis var. panigrahiana R.D.Dixit. Southern Asia (India).
-
Osmunda regalis var. brasiliensis (Hook. & Grev.) Pic. Serm. Tropical regions of Central and South America; treated as a synonym of var. spectabilis by some authors.
-
Osmunda regalis var. spectabilis (Willdenow) A.Gray. Eastern North America. Sterile fronds to 100 cm tall. Now accepted as a separate species, Osmunda spectabilis.
Similar species
There are three very similar species,
Osmunda spectabilis,
Osmunda lancea and
Osmunda japonica. Recent genetic analysis (Metzgar et al., 2008) has shown that the New World varieties are in a clade that is sister to the Old World varieties of
Osmunda regalis. If this is true, then
O. lancea and
O. japonica should either be regarded as varieties of
O. regalis, or, conversely,
O. regalis var. spectabilis should be regarded as a separate species,
Osmunda spectabilis Willdenow. The var.
brasiliensis would then be
Osmunda spectabilis Willdenow var.
brasiliensis Hooker & Greville.
Cultivation
Osmunda regalis is widely cultivated in
temperateness 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
soil pH, 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.
Other uses
The
, along with those of other species of
Osmunda, are used for the production of
osmunda fibre, used as a growing medium for cultivated
and other
epiphyte.
According to Slavic mythology, the sporangia, called "Perun's flowers", have assorted magical powers, such as giving their holders the ability to defeat , 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.
-
Hyde, H. A., Wade, A. E., & Harrison, S. G. (1978). Welsh Ferns. National Museum of Wales.
-
Metzgar, Jordan S., Judith E. Skog, Elizabeth A. Zimmer, and Kathleen M. Pryer (2008). "The Paraphyly of Osmunda is Confirmed by Phylogenetic Analyses of Seven Plastid Loci." Systematic Botany, 33(1): pp. 31–36
External links
