Osmundastrum cinnamomeum (Cinnamon Fern)

Plant Info
Also known as:
Family:Osmundaceae (Royal Fern)
Life cycle:perennial
Habitat:part shade, shade; marshes, wet woods, bogs, swamps
Fruiting season:spring
Plant height:24 to 40 inches
Wetland Indicator Status:GP: FACW MW: FACW NCNE: FACW
MN county distribution (click map to enlarge):Minnesota county distribution map
National distribution (click map to enlarge):National distribution map

Pick an image for a larger view. See the glossary for icon descriptions.

Detailed Information


[photo of fiddleheads] As the fern emerges from the ground in early spring it is covered in a light brownish-colored wool but it is quickly lost.

Leaves and stems: Leaf attachment: basal Leaf type: compound

[photo of sterile frond] Leaves are once compound, generally lance-shaped in outline, up to 40 inches long and 10 inches across, widest below the middle and gradually tapering at the tip end. Leaflets have deep lobes, rounded to slightly pointed, and forked lateral veins on the underside. The leaves are nearly erect to arching and grow in a circular clump with the fertile spike (if present) growing in the middle.

[photo of leaflet base] There is a persistent tuft of whitish to brownish hair on the underside of the leaf at the junction of the main stem and leaflet mid-nerve. Stem is green and slightly grooved on the upper side.

Spores: Fruit type: spores on stalk

[photo of spores] In mid to late spring, 1 or more spike-like fertile leaves, nearly as tall as the sterile leaves, grow in the center of the leaf clump. Fertile leaves are hairy and composed of very small bead-like capsules (which contain the spores) that are initially green but turn cinnamon-colored with maturity. After releasing the spores, the fertile leaf dies and is inconspicuous.


Since the leaves, size and overall structure of Cinnamon Fern, Ostrich Fern (Matteuccia struthiopteris) and Interrupted Fern (Osmunda claytoniana) closely resemble each other, they can be distinguished by the fruiting fertile fronds. If spores are not present, the easiest way to distinguish the 3 species is to turn over the leaf and see if there is a tuft of hair at the junction of the main stem and leaflet - only Cinnamon Fern has this feature. Cinnamon Fern was formerly known as Osmunda cinnamomea but was recently moved to genus Osmundastrum, presumably because genetic testing found it not as closely related to Interrupted Fern as previously thought. While in some areas of the country Cinnamon Fern may reach heights of 5 feet, it doesn't get quite that tall in Minnesota.

Native Plant Nurseries, Restoration and Landscaping Services ↓

Map of native plant resources in the upper midwest

  • Prairie Restorations - Bringing people together with the land
  • Landscape Alternatives
  • ReWild Native Gardens
  • Out Back Nursery
  • Shop for native seeds and plants at PrairieMoon.com!

More photos

Photos by K. Chayka taken at Long Lake and Sucker Lakes in Ramsey County. Other photos courtesy Peter M. Dziuk.


Have you seen this plant in Minnesota, or have any other comments about it?

Posted by: luciearl - Lake Shore, MN
on: 2016-07-17 09:11:42

A few of these grow in the ditch at my parent's place. Wish I could transplant a portion to my property a mile away, but the roots are almost like tree roots making it almost impossible to dig up.

Posted by: Bill S. - TWO HARBORS
on: 2017-05-23 15:16:48

I believe I have a bunch of these just on the southern edge of Superior National Forest.

Posted by: Michael Cuppy
on: 2018-05-20 08:39:01

Can you eat the fiddle heads

Posted by: K. Chayka
on: 2018-05-20 12:19:38

Don't eat fuzzy fiddleheads.

Posted by: Nancy Docherty - Tamarack Nature Reserve Woodbury
on: 2022-05-23 15:05:39

Seen from board walks

Posted by: Susan Premo - George Washington state forest
on: 2022-06-14 14:41:22

First time seeing them, sure can tell right away! Beautiful right next to a beautiful bog lake. Camping nearby at Beatrice lake.

Posted by: Karla Roberts - Blaine
on: 2023-03-24 08:45:06

These native ferns grew in our development in the late 1990s. I transplanted a bucketful of them from an undeveloped lot to my backyard in 1998. Each spring, for decades, they returned. Over the summer they were a beautiful 2 foot tall blanket of waving fronds under the mixed deciduous trees on the west side of our property. We lived on the SE side of the Anoka County airport.

Post a comment

Note: All comments are moderated before posting to keep the riff-raff out. An email address is required, but will not be posted—it will only be used for information exchange between the 2 of us (if needed) and will never be given to a 3rd party without your express permission.

For info on subjects other than plant identification (gardening, invasive species control, edible plants, etc.), please check the links and invasive species pages for additional resources.


Note: Comments or information about plants outside of Minnesota and neighboring states may not be posted because Id like to keep the focus of this web site centered on Minnesota. Thanks for your understanding.