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• Osmunda regalis

Osmunda regalis — royal fern

Facts

Royal fern is a cosmopolitan species, and may be the only vascular plant found on all seven continents. It is common throughout New England in swamps, shorelines and riparian forests. The ferile pinnae of royal fern rise above the sterile pinnae, looking somewhat like a crown, hence the name.

Habitat

Floodplain (river or stream floodplains), forests, shores of rivers or lakes, swamps, wetland margins (edges of wetlands)

Characteristics

• Growth form

  Life form

  the plant is herbaceous and terrestrial

  Life stage

  the plant is visible as a typical leaf-bearing fern (sporophyte)

  Spore-bearing leaflets

  the spore-bearing fronds are slightly different from the sterile fronds

• Leaves

  Features of leaves

  there are no special features on the leaves

  Leaf blade length

  20–150 cm

  Leaf blade shape

  the leaf blades are widest above the base, then taper broadly towards the tip (ovate)

  Leaf blade tip shape

  • the tip of the leaf blade is a sharp point (acute)
  • the tip of the leaf blade is rounded

  Leaf blade width

  At least 15 cm

  Leaf divisions

  • the leaf blade is three times compound (divided into leaflets, which are further divided into leaflets, which are further divided into leaflets), or more
  • the leaf blade is twice compound (divided into leaflets, which are further divided into leaflets)

  Leaf lifespan

  the leaves drop off in winter

  Leaf stalk color

  • green
  • red or red-brown to purple or black
  • yellow to brown

  Leaf stalk hairs

  there are no hairs on the leaf stalk

  Leaf stalk length

  128–577 mm

  Leaf stalk relative length

  the leaf stalk is more than three quarters as long as the blade

  Leaf stalk scale location

  there are no scales on the leaf stalk

  Leaf stalk scales

  there are no scales on the leaf stalk

  Leaf stalk vessels

  1 bundle, U-shaped

  Leaf vein branching

  the secondary veins of the leaf blade branch dichotomously (two equal branches at each branch point)

  Leaf vein tips

  the veins go all the way to the edge of the leaf blade

  Leaflet relative size

  the bottom leaflets are about half as long as, to slightly longer than, the leaflets from the middle of the frond

  Leaflet stalks

  the leaflets are stalked

  Lobe or leaflet length

  150–300 mm

  Lobe or leaflet pairs

  2–7

  Lobe or leaflet shape

  the lobe or leaflet is widest below the middle and tapering at both ends; lance-shaped

  Lobe or leaflet width

  50–150 mm

  Plant growth form

  the leaves grow from a rhizome growing at or below the ground

  final leaf segment margin

  • the topmost lobe or leaflet of the leaf blade has a smooth or lobed edge
  • the topmost lobe or leaflet of the leaf blade has an edge with teeth

• Place

  Habitat

  • terrestrial
  • wetlands

  New England state

  • Connecticut
  • Maine
  • Massachusetts
  • New Hampshire
  • Rhode Island
  • Vermont

  Specific habitat

  • edges of wetlands
  • forests
  • river or stream floodplains
  • shores of rivers or lakes
  • swamps

• Spores or spore cones

  Sorus features

  there are no special features on the sorus

  Sorus shape

  there are no sori, or they are concealed in leaf segments or hardened, capsule-like structures derived from a modified leaflet

  Sporangia location

  the spores cover the surfaces of modified leaves or leaflets

  Sporangium type

  the sporangia are opaque without an annulus and usually without a stalk (leptosporangiate)

  Spore forms

  there is only one type of spore present

Wetland status

Occurs only in wetlands. (Wetland indicator code: OBL)

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae