Thelypteris Ferns

Thelypteris
A genus of rhizome spreading Ferns that generally prefer moist acidic soil.
Deer resistant.

* photo taken on May 1 2010 @ U.S. National Arboretum

* photo of unknown internet source


Thelypteris acuminata
A very attractive groundcover Fern native to Sichuan Province in China, that can reach as much as 20 inches x 6 feet in just 5 years, eventually exceeding 10 feet across. Great for naturalizing in a woodland garden.
Hardy zones 7 to 9

Thelypteris beddomei ( Korean Maiden Fern )
A handsome, rhizomatous groundcover Fern, reaching as much as 1.5 x 6 feet in 4 years, eventually wider spreading. This Korean native makes an excellent woodland groundcover.
The lacy, upright fronds, up to 18 x 3 inches, are bright green.
Hardy zones 6 to 9 in partial shade.

Thelypteris decursive-pinnata ( Japanese Beech Fern )
Also called Phegopteris decursive-pinnata. A handsome, deciduous to semi-evergreen groundcover Fern, native to central & eastern China, Korea & Japan, that spreads underground to form large vigorous colonies reaching a maximum size of 2 x 5 feet.
The attractive, stiffly erect, triangular fronds, up to 24 x 6 inches, remains luxuriant bright green until very late in autumn. It is an excellent Fern for use as groundcover in shaded gardens.
Hardy zones 4 to 9 in partial to full shade on slightly acidic, moist fertile soil. It is easy to grow, even tolerating dry shade and wet sites.

* photo taken on May 8 2010 @ McCrillis Gardens, Bethesda, MD

* photo taken on Aug 29 2013 in Clarksville, MD

* photo taken on July 24 2014 in Columbia, MD

* photos taken on July 25 2016 in Columbia, MD

* photo taken on Sep 7 2016 in Columbia, MD

* photos taken on Aug 13 2017 in Columbia, MD

* photos taken on Sep 26 2018 in Columbia, MD

* photo taken on July 27 2019 in Columbia, MD

* photo taken on Apr 22 2020 in Columbia, MD

* photos taken on July 23 2020 in Columbia, MD

* photos taken on Aug 27 2020 in Columbia, MD

* photos taken on Sep 2 2020 in Columbia, MD

* photos taken on June 10 2021 in Columbia, MD

* photo taken on Aug 4 2021 @ U.S. National Arboretum, Washington, DC

* photos taken on July 13 2023 in Columbia, MD

* photos taken on Aug 7 2023 in Columbia, MD

Thelypteris hexagonoptera ( Broad Beech Fern )
Also called Phegopteris hexagonoptera. A rapid rhizome-spreading, deciduous Fern forming a dense clump up to 2.5 x 2 feet, that eventially can form broad colonies. This very attractive rhizome spreading Fern is native to moist woods of eastern North America ( from Minnesota to the Upper Peninsula of Michigan to Lion's Head, Ontario to Parry Sound, Ontario to far southern Quebec to southern Maine; south to eastern Texas and the northern Florida panhandle ). It has declined considerably in southern Ontario though was common in rich woods around Windsor before 1900. It was also abundant on the Ohio shore during that time.
The broad triangular fronds, up to 24 x 12 inches, with deeply cut pinnae are mid green. The foliage turns yellow then later to bronze during autumn.
Hardy zones 3 to 8 in full shade on acidic to neutral, well drained soil. Tolerates some sun and drought.

* photos taken on June 30 2013 @ U.S. National Arboretum, DC

* photos taken on July 25 2016 in Columbia, MD

Thelypteris kunthii ( Southern River Fern )
Also called Thelypteris normalis and Southern Shield Fern. A very fast growing, spectacular, spreading, deciduous Fern reaching a maximum height of 5 feet, that is native from eastern Texas to South Carolina, south in the the Caribbean and also Mexico to northern Brazil. In ideal conditions, it can form extensive colonies, reaching up to 5 feet across in 5 years, eventually more. It is found in swamps and bottomland woods in the wild.
The large, triangular fronds, up to 48 x 12 ( rarely over 24 x 6 ) inches, are glossy deep green, turning to bronze during autumn.
The new fronds continue to appear all summer long.
Hardy zones 7 to 10 ( 6 on protected sites with winter mulch ) preferring a good, fertile moist soil though can tolerate relatively dry soil in the shade. It is tolerant of sun on wet sites and can also tolerate up to 9 months of drought when it is dormant.

Thelypteris nevadensis ( Sierra Water Fern )
A deciduous Fern native from southwestern British Columbia, south to northern California and Nevada. It is also native to northern Idaho however is critically endangered there being known from only 2 sites. The pinnate fronds, up to 48 inches in length, are composed of pinnae up to 4 x 1 inches in size.

* photo of unknown internet source


Thelypteris noveboracensis ( New York Fern )
A very fast spreading, deciduous Fern, forming a clump or colony reaching a maximum size of 4 x 10 feet, that is native to eastern North America ( from the Upper Peninsula of Michigan to Sault Ste Marie to Chalk River, Ontario to Newfoundland; south to central Arkansas to Alabama and Georgia ). It is endangered in Illinois. Now rare in the Windsor/Essex County, Ontario region; it was locally abundant around Windsor before 1900. It occurred sporadically on the Ohio shore during that time. It is found in rich, low, moist woods in the wild. This very strong growing Fern can spread very aggressively by long creeping rhizomes but is good for use as a woodland groundcover where room permits. The roots of this Fern release a natural herbicide into the soil that supresses some of its competition, Prunus serotina -Black Cherry is expecially vulnerable and can easily die from this chemical.
In swampy woodlands with soil PH under 4; this often becomes a dominent groundcover plant covering extensive areas.
The narrow fronds, up to 36 x 7 inches, are yellowish-green.
Hardy zones 2 to 8 in partial shade on moist, well drained soil. Tolerates sun if soil is moist and also tolerates very wet soil or drought on shade sites.

* photo of unknown internet source

* photo taken on June 30 2013 @ U.S. National Arboretum, DC

* photos taken Aug 2016 @ Patuxent Research Refuge, Laurel, MD

* photos taken on Sep 22 2016 @ Patuxent Research Refuge, Laurel, MD

* photos taken on Sep 25 2016 near Reisterstown, MD

* photos taken on Oct 23 2023 @ Patuxent Wildlife Refuge, Laurel, MD

* photo taken by Robert H. Mohlenbrock @ USDA-NRCS PLANTS Database

Thelypteris palustris ( Marsh Fern )
A rapid growing, wide spreading Fern, reaching up to 5 x 5 ( rarely over 3 ) feet, that is native to marshes and swampy woods in North America ( from central Manitoba to Cochrane, Ontario to Newfoundland; south to eastern Texas to southern Florida ). It is endangered in Ontario though was very abundant on the Lake Erie Islands as well as the Ohio shoreline before 1900. It was also common in Detroit during the presettlement era. It is fast to very invasive spreading ( spreads up to 3.5 feet per year ) due to its spreading rhizomes. Marsh Fern can easily spread to form a clump up to 5+ feet across in just 5 years, sometimes eventually much more. Looks great planted next to ponds.
The fronds, up to 48 x 6 inches, are blue-green.
Hardy zones 2 to 8 in partial to full shade on moist, well drained soil. Tolerates swampy conditions and some sun if on wet soil.

* photos taken on Aug 23 2016 @ Patuxent Research Refuge, Laurel, MD

* photos taken Aug 2016 @ Patuxent Research Refuge, Laurel, MD

* photos taken on Sep 18 2016 @ Patuxent Research Refuge, Laurel, MD

* photo taken on Sep 25 2016 near Reisterstown, MD

* photos taken on July 6 2022 @ Point Pelee Ntl Park, Leamington, ON

Thelypteris patens
A huge tropical version of the Thelypteris Ferns, with fronds reaching up to 7 x 2 feet each. It is native to southern Florida, the Caribbean and Mexico south into northern Argentina.
The frond blade can be up to 40 inches long.
Hardy zones 10 to 12

Thelypteris phegopteris ( Northern Beech Fern )
Also called Phegopteris connectilis. A low growing, deciduous Fern forming a clump up to 2 feet x 20 inches, that is excellent for use as groundcover though may be invasive on some sites. It is a widespread native to boreal forests of northern North America ( from Nome, Alaska to central Alaska to southeast Yukon to Churchill, Manitoba to Lansdowne House, Ontario to Cochrane, Ontario to Labrador & Newfoundland; south to Washington State to northern Idaho to Sask. to eastern Iowa to northern Illinois to central Ohio to West Virginia to Maryland ) and Eurasia.
The flimsy, graceful, triangular fronds, up to 20 x 6 inches, are bright green.
The new fronds continue to appear all summer long.
Hardy zones 2 to 8

Thelypteris puberula ( Sonoran Maiden Fern )
A moderate growing fern, reaching up to 3 x 3 feet, that is native to the southwestern U.S. ( from southern California to the mountains of central Arizona; south to the Mexican border ).

* photo of unknown internet source


Thelypteris serrata
A huge tropical version of the Thelypteris Ferns, with fronds reaching up to 8 feet x 2 inches each. It is native to swamps in central and southern Florida, the Caribbean and Mexico south into northern Argentina.
Hardy zones 9 to 12