categoryZFerns Ferns List 

ROYAL FERN

Osmunda regalis

[Osmundaceae]

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category
category8Ferns
status
statusZnative
type
typeZspiked
stem
stem8round

28th June 2012, Bridgewater Canal, Sale. Photo: © RWD
The tallest and perhaps most graceful fern in the UK, usually up to 2m high but can grow even higher to 3m or 4m.


28th June 2012, Bridgewater Canal, Sale. Photo: © RWD
Being hidden by large sterile fronds the sporing shoots can look like the flowering spikes of a fruiting Dock plant, but are a more orangy brown. Because of this it is sometimes known as Flowering Fern.


28th June 2012, Bridgewater Canal, Sale. Photo: © RWD
Grows in wet woods and fens (or beside the un-disturbed far side of canals) usually on acid soils in the West.


28th June 2012, Bridgewater Canal, Sale. Photo: © RWD
The fertile fronds bearing spores stick upright like flowering spikes. The sterile fronds taper abruptly at the ends and are doubly pinnate with large oblong leaflets. A different fern pokes through the fronds to daylight.


4th July 2012, Bridgewater Canal, Sale, Gtr M/cr. Photo: © RWD
The fertile fronds become more compact before turning a rusty brown after releasing the spores.


4th July 2012, Bridgewater Canal, Sale, Gtr M/cr. Photo: © RWD
Sporing fronds stick bolt upright with their side-branches bending upwards.


4th July 2012, Bridgewater Canal, Sale, Gtr M/cr. Photo: © RWD
The summit of a fertile and sporing frond.


4th July 2012, Bridgewater Canal, Sale, Gtr M/cr. Photo: © RWD
When ripe the spore cases split open releasing the spores. It is possible that the yellowish specks are stray spores.


4th July 2012, Bridgewater Canal, Sale, Gtr M/cr. Photo: © RWD
Young plants. Fertile fronds are erect, shorter than sterile fronds and bear densely clustered sporangia which are green when un-ripe.


5th July 2012, Bridgewater Canal, Dunham Massey, Gtr M/cr. Photo: © RWD
Fertile fronds at top, sterile fronds underneath. Fertile fronds usually bear 2 to 3 pinnae of paired sterile fronds beneath them (only one pair shown here).


5th July 2012, Bridgewater Canal, Dunham Massey, Gtr M/cr. Photo: © RWD
Leaflets from top surface.


5th July 2012, Bridgewater Canal, Dunham Massey, Gtr M/cr. Photo: © RWD
Fertile fronds bearing densely-packed sporangia spheres.


5th July 2012, Bridgewater Canal, Dunham Massey, Gtr M/cr. Photo: © RWD
The sun-facing side of the fertile fronds. Stalks appear flat on at least one face.


5th July 2012, Bridgewater Canal, Dunham Massey, Gtr M/cr. Photo: © RWD
The sporangia are amassed in grape-shaped bundles. Green sporangia not yet ripe, when ripe they will split open to release the spores and turn an orangish brown.


5th July 2012, Bridgewater Canal, Dunham Massey, Gtr M/cr. Photo: © RWD


5th July 2012, Bridgewater Canal, Dunham Massey, Gtr M/cr. Photo: © RWD


28th June 2012, Bridgewater Canal, Sale. Photo: © RWD
The fronds are broad, slightly drooping and doubly pinnate.


28th June 2012, Bridgewater Canal, Sale. Photo: © RWD
Leaflets are oblong and quite different to those of other ferns.


4th July 2012, Bridgewater Canal, Sale, Gtr M/cr. Photo: © RWD
Young fronds lime-green, older ones are a darker green (left).


5th July 2012, Bridgewater Canal, Dunham Massey, Gtr M/cr. Photo: © RWD
Sterile leaflets by transmitted light show yellowish veins.


5th July 2012, Bridgewater Canal, Dunham Massey, Gtr M/cr. Photo: © RWD
The veins bifurcate twice before reaching the edge where they result in very shallow rounded teeth, resulting in 4 times as many teeth as there are starting veins - about 50 each side in the above case. The pinnules have exceedingly short stems before the leaflet begins.


Uniquely identifiable characteristics

Distinguishing Feature : The 'flowering spike' containing catkin-like sets of orange-brown spores. The large doubly-pinnate frond of oblong leaflets. It's immense height compared to other ferns!

No relation to : Pennyroyal [a plant with similar name].

The only example of its genus in the UK. Grows mainly in the West preferring acid soils in damp woods and woodland bogs or fens or on the far banks of un-disturbed canals. It is becoming rarer due to wetland drainage. There are four varieties worldwide, but only the one, Osmunda regalis var. regalis, grows in the UK.


  Osmunda regalis  ⇐ Global Aspect ⇒ Osmundaceae  

Distribution
 family8Osmundaceae

 BSBI maps
genus8Osmunda
Osmunda
(Royal Fern)

ROYAL FERN

Osmunda regalis

[Osmundaceae]