Rhode Island Ferns

William W. Bailey, a 19th century Brown University botanist, described Rhode Island ferns as bewitching plants of very various habitats waving their broad plumes in the swamps or nestling under walls. He wrote of the rigid and glossy, evergreen Christmas Fern and the Maidenhair Fern with its polished ebony stems and light graceful sprays. Bailey listed forty species of ferns growing in Rhode Island. Our list is comprised of forty-six species plus six hybrids. Most of these hybrids are produced within the genus Dryopteris, Wood Ferns. Unlike flowering plants, ferns grow from spores, not seeds. Spores may be produced on the undersides of fronds or on separate stalks. When mature, the spores fall to the ground and germinate to produce the gametophyte generation in the life cycle of the fern. The gametophyte, also called prothallus, contains the structures which produce the sperm and the egg. Fertilization of the egg by the sperm results in the production of a sporophyte. This is the generation in the life cycle of the fern which we know as the “adult fern”.

Our ferns range in size from the tiny Least Moonwort (Botrychium simplex) which may be as small as one and one-half inches tall to Cinnamon Fern (Osmunda cinnamomea) which can grow up to six feet tall.

Ferns grow in various habitats ranging from woods or swamps to fields and cliffs. Some grow on limestone cliffs, others on granite cliffs.  One of our native ferns can climb to the height of twenty feet. One species, a cliff dweller, has evolved the ability to walk down moss-covered rocks by producing new plants at the tips of its fronds. Habitat information for each species is contained in the pages that follow. In addition, the counties in which the ferns grow and the state status are included.

Francis Underwood

The information on Rhode Island Ferns comes from several sources. The dates for mature spores are based on Seymour's "Flora of New England". The county and status information is from Rick Enser's Rare Plants of RI and, for ferns not on the Rare Plant List, the status is taken from Gil George's Rhode Island Botanical Survey Check List, published in 1999. Francis Underwood provided habitat information and Don Lubin made sure the nomenclature was up-to-date and has added the identification notes.

Our Thanks to
Don Lubin
for helping us with this project
and allowing us to use his photos.

If you know where you want to go,
click on the name of the genus

Genera on page 1
Genera on page 2
Genera on page 3
Adiantum Deparia Pellaea
Asplenium Dryopteris Phegopteris
Athyrium Gymnocarpium Polypodium
Botrychium Lygodium Polystichum
Cystopteris Matteuccia Pteridium
Dennstaedtia Onoclea Thelypteris
  Ophioglossum  Woodsia
  Osmunda Woodwardia

Fern Home pageBecause of its length, this article has been broken into three web pages. To return to this page from other Fern pages, click on this button at the bottom of the other pages.

 

 

 

 

 

 

 

For a key to the status codes, click here.

To learn about the life cycle of a fern, click here

To down load a
pdf (
5.8 mb) of
RI Ferns (rev. 10/2011), click here.

 

 

 

 

 

 

 

Click on the thumbnail image to view a larger photo.
 
Maidenhair fern close up
Botanical Name:
 
Adiantum pedatum 
Common Name:
 
Maidenhair Fern
Habitat:
 
Rich woods
Spores can be found:
 
July to September
 
State Status:
 
U
Sites in State:
 
Counties found in:
 
Providence,Kent, Washington
 
Maidenhair Fern
Notes from Don Lubin:
 
Unique, delicate frond shape. Dark wiry stems were used to make baskets.
 
 
Mountain Spleenwort
Botanical Name:
 
Asplenium montanum 
Common Name:
 
Mountain Spleenwort
Habitat:
 
Non-calcareous rocks
Spores can be found:
 
5/25 — 8/18
 
State Status:
 
SE
Sites in State:
 
1
Counties found in:
 
Providence
 
 
Notes from Don Lubin:
 
Small fern, rare in New England.
 
 
Ebony Spleenwort
Botanical Name:
 
Asplenium platyneuron 
Common Name:
 
Ebony Spleenwort
Habitat:
 
Thin soils of rocky slopes
Spores can be found:
 
7/17 — 10/29
 
State Status:
 
A
Sites in State:
 
Counties found in:
 
All
 
Ebony Spleenwort spore cases
Notes from Don Lubin:
 
Dark stipe and rachis, pinnae eared like Christmas fern.
 
 
Walking Fern
Botanical Name:
 
Asplenium rhizophyllum 
Common Name:
 
Walking Fern
Habitat:
 
Shaded high pH rocks
Spores can be found:
 
5/13 — 10/1
 
State Status:
 
SE
Sites in State:
 
1
Counties found in:
 
Providence
 
Walking Fern with plantlet
Notes from Don Lubin:
 
Grows flat on rock surface. New plants grow from frond tips.
 
 
Maidenhair Spleenwort
Botanical Name:
 
Asplenium trichomanes
Common Name:
 
Maidenhair Spleenwort
Habitat:
 
Rock crevices and shaded ledges
Spores can be found:
 
6/13 — 8/20
 
State Status:
 
SC
Sites in State:
 
9
Counties found in:
 
Providence; Kent;Washington
 
Maidenhair Spleenwort growing spreading along ledge
Notes from Don Lubin:
 
Lovely little fern with dark stipe and rachis. Pinnae not eared.
 
Maidenhair Spleenwort growing in crevice      
 
 
Lady Fern
Botanical Name:
 
Athyrium filix-femina (L.) Roth ex Mert. 
Common Name:
 
Lady Fern
Habitat:
 
Moist to wet woodlands
Spores can be found:
 
7/14 — 9/8
 
State Status:
 
C
Sites in State:
 
Counties found in:
 
All
 
Lady Fern spore cases
Notes from Don Lubin:
 
Propagates readily by spores, grows unbidden in lawns. Curved sori form herringbone pattern.
 
 
Cut-leaf Grape Fern
Botanical Name:
 
Botrychium dissectum 
Common Name:
 
Cut-leaf Grape Fern
Habitat:
 
Dry to moist woodlands
Spores can be found:
 
7/23 — 9/25 (10/2)
 
State Status:
 
O
Sites in State:
 
Counties found in:
 
All
 
Notes from Don Lubin:
 
Degree of cutting highly variable. Emerges midsummer, changes from green to bronze in late autumn.
 

Upper photos:
Botrychium dissectum f. dissectum

Lower photo:
Botrychium dissectum f. obliquum

 
 
Narrow Triangle Grape Fern
Botanical Name:
 
Botrychium lanceolatum 
Common Name:
 
Narrow Triangle Grape Fern
Habitat:
 
Mesic woodlands
Spores can be found:
 
(6/14) 6/24 — 8/31 (9/17)
 
State Status:
 
SC
Sites in State:
 
2
Counties found in:
 
Providence; Kent, Washington
 

 

Cutleaf Grape Fern

Notes from Don Lubin:
 
Wide tropophore projects at right angle, sporophore branched.
 
 
Daisyleaf Grape Fern
Botanical Name:
 
Botrychium matricarifolium 
Common Name:
 
Daisyleaf Grape Fern
Habitat:
 
Deciduous woodlands and rarely open areas
Spores can be found:
 
(6/13) 6/24 — 8/20
 
State Status:
 
SC
Sites in State:
 
4
Counties found in:
 
Providence; Kent, Washington
 
 
Notes from Don Lubin:
 
Narrow tropophore projects at acute angle, sporophore unbranched.
 
 
Leathery Grape Fern
Botanical Name:
 
Botrychium multifidum 
Common Name:
 
Leathery Grape Fern
Habitat:
 
Fields or openings in woodlands
Spores can be found:
 
7/21 — 9/23
 
State Status:
 
R
Reported found but
no sites listed
Sites in State:
 
?
Counties found in:
 
?
 
 
Notes from Don Lubin:
 
Stipe particularly stout, pinnules overlap, smaller towards frond tips.
 
 
Blunt-lobed Grape Fern
Botanical Name:
 
Botrychium oneidense 
Common Name:
 
Blunt-lobed Grape Fern
Habitat:
 
Moist to wet woodlands and swamps
Spores can be found:
 
7/23 — 9/25 (10/2)
 
State Status:
 
SH
Sites in State:
 
0 (1899)
Counties found in:
 
Providence
 
 
Notes from Don Lubin:
 
Pinnules rounder than B. dissectum. Does not turn bronze in autumn.
 
 
Dwarf Grape Fern
Botanical Name:
 
Botrychium simplex 
Common Name:
 
Least Moonwort
Habitat:
 
Moist fields and woodlands
Spores can be found:
 
6/26 — 8/8
 
State Status:
 
R
Sites in State:
 
Counties found in:
 
Providence,Kent, Washington
 
Dwarf Grape Fern fruiting bodies
Notes from Don Lubin:
 
[a moonwort, not a grape fern]
 
 
Least Moonwort
Botanical Name:
 
Botrychium tenebrosum 
Common Name:
 
Shade-loving Moonwort
Habitat:
 
Shaded woodlands
Spores can be found:
 
6/26 — 8/8
 
State Status:
 
R
Sites in State:
 
1
Counties found in:
 
Kent (?)
 
Least Moonwort close up
 
 
 
Rattlesnake Fern
Botanical Name:
 
Botrychium virginianum 
Common Name:
 
Rattlesnake Fern
Habitat:
 
Rich woodlands
Spores can be found:
 
6/13 — 8/14
 
State Status:
 
O
Sites in State:
 
Counties found in:
 
Providence, Kent, Washington
 
 
Notes from Don Lubin:
 
Largest, most 'fernlike' of the Botrychium, with horizontal three-part frond like Bracken. Spore stalk rises from center of frond.
 
 
Southern Bladder fern
Botanical Name:
 
Cystopteris protrusa 
Common Name:
 
Southern Bladder Fern
Habitat:
 
On rich soil of woodlands
Spores can be found:
 
6/24 — 9/9
 
State Status:
 
Possibly in RI
Sites in State:
 
Counties found in:
 
 
 
Notes from Don Lubin:
 
Generally grows in soil rather than from rock crevices.
 
 
Fragile Fern
Botanical Name:
 
Cystopteris tenuis 
Common Name:
 
Fragile Fern
Habitat:
 
On rocks and sometimes on shaded walls with mortar
Spores can be found:
 
6/24 — 9/9
 
State Status:
 
O
Sites in State:
 
Counties found in:
 
Providence, Kent, Washington, Newport
 
Fragile Fern sori
Notes from Don Lubin:
 
Delicate 'airy' blade. Grows only occasionally in soil, more often on rocks.
 
 
Hay-scented Ferns
Botanical Name:
 
Dennstaedtia punctilobula 
Common Name:
 
Hay-scented  Fern
Habitat:
 
Ubiquitous in fields, rocks and woodlands
Spores can be found:
 
7/1 — 9/15
 
State Status:
 
C
Sites in State:
 
Counties found in:
 
All
 
Hay-scented Fern Close up
Notes from Don Lubin:
 
Fronds emerge singly, not in clusters. Note fine white hairs on stipe. Pinnule edges rounded, with no teeth.
   
Classic stand Hay-sented Fern
 
     
 

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