• You are here:
• Dichotomous Key
• Pteridaceae
• Adiantum
• Adiantum pedatum

Adiantum pedatum — northern maidenhair fern

Facts

Maidenhair fern is found in rich, moist forests throughout New England. It has a distinctive dark, wiry stem and rachis. Both the entire blade and individual pinnules (sub-leaflets) are fan-shaped. Native Americans made use of this plant to treat a variety of conditions, including rheumatism, fever, heart disease, and asthma, as well as using the stems in basketry and to insert in a pierced ear lobe to keep it from closing.

Habitat

Forests, talus and rocky slopes

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

  the petiole (leaf stalk or stipe) appears to fork into two equal halves

  Leaf blade length

  15–30 cm

  Leaf blade shape

  the leaf blades are roughly fan-shaped

  Leaf blade tip shape

  the tip of the leaf blade is a blunt point (obtuse)

  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

  Leaf lifespan

  the leaves drop off in winter

  Leaf stalk color

  red or red-brown to purple or black

  Leaf stalk hairs

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

  Leaf stalk length

  100–600 mm

  Leaf stalk relative length

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

  Leaf stalk scale location

  the scales are present only on the lower half of the leaf stalk

  Leaf stalk scales

  • the leaf stalk has 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 stalks

  the leaflets are stalked

  Lobe or leaflet length

  40–170 mm

  Lobe or leaflet shape

  the lobe or leaflet is rectangular but with rounded ends (oblong)

  Lobe or leaflet width

  Up to 40 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

• Place

  Habitat

  terrestrial

  New England state

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

  Specific habitat

  • forests
  • talus or rocky slopes

• 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 hidden inside hardened, rolled-under leaf segments

  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