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• Dennstaedtiaceae
• Pteridium
• Pteridium aquilinum

Pteridium aquilinum — bracken fern

Facts

Bracken fern often becomes dominant after disturbances such as fire, logging and grazing due to its deep rhizome. Humans have used bracken fern for thatch, livestock, bedding, and food, though it does contain some toxic compounds.

Habitat

Anthropogenic (man-made or disturbed habitats), forest edges, forests, meadows and fields, woodlands

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 similar in size and shape to the sterile fronds

• Leaves

  Features of leaves

  there are nectaries near the base of the leaf blade

  Leaf blade length

  20–80 cm

  Leaf blade shape

  • the leaf blades are roughly triangular
  • 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)

  Leaf blade width

  At least 20 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

  Leaf lifespan

  the leaves drop off in winter

  Leaf stalk color

  yellow to brown

  Leaf stalk hairs

  • the leaf stalk has hairs
  • there are no hairs on the leaf stalk

  Leaf stalk length

  100–1000 mm

  Leaf stalk relative length

  the leaf stalk is more than a quarter, but less 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

  10 or more bundles

  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 pairs

  5–24

  Lobe or leaflet shape

  • the lobe or leaflet is extremely narrow, thread-like
  • the lobe or leaflet is rectangular but with rounded ends (oblong)
  • the lobe or leaflet is widest below the middle and broadly tapering at both ends; egg-shaped

  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

• Place

  Habitat

  terrestrial

  New England state

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

  Specific habitat

  • edges of forests
  • forests
  • man-made or disturbed habitats
  • meadows or fields
  • woodlands

• 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 are clustered on sori on the lower surface of the leaf blade

  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

Usually occurs in non-wetlands, but occasionally in wetlands. (Wetland indicator code: FACU)

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae