American Hart's-tongue Fern / Center For Plant Conservation
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Plant Profile

American Hart's-tongue Fern (Asplenium scolopendrium var. americanum)

This plant, with its long, linear leaves, growing in its mossy, green habitat. Photo Credit: Brian Parsons
  • Global Rank: T3 - Vulnerable
  • Legal Status: Federally Threatened
  • Family: Aspleniaceae
  • State: AL, MI, NJ, NY, ON, TN
  • Nature Serve ID: 135863
  • Lifeform: Forb/herb
  • Categories of Interest: Ferns
  • Date Inducted in National Collection: 04/01/1990

Asplenium scolopendrium var. americanum, or American hart's tongue fern, is the North American variety of a European species that was described in 1753 by Linnaeus as Phyllitis scolopendrium. This variety was discovered in North America in 1849 in Tennessee, and since then has been found in Alabama, New York, Michigan, and Ontario Canada. The American hart's tongue fern differs from its European relative based on several distinct morphological (shorter fronds, fewer indusia, etc. (Fernald 1935)) and genetic features (144 rather than 72 chromosomes (Britton 1953)). (USFWS 1989) American hart's-tongue fern forms rosettes of evergreen, undivided fronds, 5 - 17 inches long (12 - 42 cm), - 1 inches wide (2 - 4.5 cm) with two lobes at the base, making the base heart-shaped. The green petiole portion of this frond is from 1 to 5 inches (3 to 12 cm) long, with cinnamon-colored scales on its surface. Fronds arise in clusters from short, creeping rhizomes that are themselves covered in cinnamon-colored scales. (USFWS 1989) Plants produce new fronds in the spring; each frond survives for two growing seasons, producing spores on year-old fronds from May through August. Spore-producing structures, the sporangia, are grouped into small, linear sori found on the upper half of the lower surface of the frond.

Where is American Hart's-tongue Fern (Asplenium scolopendrium var. americanum) located in the wild?


This species is usually found growing on or in close proximity to areas underlain by dolomitic limestone (limestone that is high in magnesium). It prefers areas with high humidity (often found near streams or waterfalls), shade, and moist soil. (USFWS 1988 and 1989)


Historically found in Alabama, Michigan, New York, Tennessee, and Ontario.

States & Provinces:

American Hart's-tongue Fern can be found in Alabama, Michigan, New Jersey, New York, Ontario, Tennessee

Which CPC Partners conserve American Hart's-tongue Fern (Asplenium scolopendrium var. americanum)?

CPC's Plant Sponsorship Program provides long term stewardship of rare plants in our National Collection. We are so grateful for all our donors who have made the Plant Sponsorship Program so successful. We are in the process of acknowledging all our wonderful plant sponsorship donors on our website. This is a work in progress and will be updated regularly.

Conservation Actions

Valerie Pence
  • 01/08/2018

In vitro cultures, cryopreserved gametophyte and sporophyte tissues, and plants are held at CREW.

Valerie Pence
  • 01/08/2018

This species was initiated into tissue culture from spores collected from Jackson Co., Alabama.  A tissue culture propagation protocol for the species has been developed at CREW (Cincinnati Zoo & Botanical Garden), as well as cryopreservation protocols for in vitro cultures of both gametophytes and sporophytes (Pence, 2015).

Nature Serve Biotics
  • 05/02/2017

This fern has specific substrate and microhabitat requirements and occurs in small, widely-separated groups of populations. Northern populations are associated with the Niagara Escarpment in southern Ontario, central New York, and eastern Upper Peninsula Michigan; small disjunct southern populations occur in sinkholes and limestone caves in northern Alabama and southcentral Tennessee with microclimates mimicking conditions at northern sites. Approximately 100 extant occurrences are known, with nearly 80% of these in Ontario; a small to moderate number are found in New York and Michigan, and Tennessee and Alabama have just one and one to two extant occurrences, respectively. Total population size in the United States appears to be 5500-6500 plants, while Ontario figures are larger, with ten to hundreds of thousands of individuals. Major threats include habitat alteration via logging, quarrying, residential and commercial development, trail construction, and rock clmbing and trampling. The majority of the southern (TN and AL) populations have declined drastically or have been extirpated since their initial discovery; conservation of these small, disjunct populations appears important to preserve the genetic variability of the taxon.

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Taxon Asplenium scolopendrium var. americanum
Authority (Fernald) Kartesz & Ghandi
Family Aspleniaceae
CPC Number 9332
ITIS 192156
Duration Perennial
Common Names American fern | American hart's tongue fern | Hart's-tongue fern | Hart's tonguefern
Associated Scientific Names Asplenium scolopendrium var. americanum | Phyllitis scolopendrium var. americana | Phyllitis japonica ssp. americana | Asplenium scolopendrium var. lindenii ( | Phyllitis fernaldiana | Phyllitis lindenii | Phyllitis scolopendrium var. lindenii | Scolopendrium lindenii
Distribution Historically found in Alabama, Michigan, New York, Tennessee, and Ontario.
State Rank
State State Rank
Alabama S1
Michigan S1
New Jersey SNA
New York S2
Ontario S3
Tennessee S1
Ecological Relationships


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