Mike Breiding's Frond Fondler.us

 

This web page is dedicated to Frances Theodora Parsons, author of the book "How to Know the Ferns," first published in 1899.

"The greatest charm the ferns possess is that of their surroundings." ~Frances Theodora Parsons

 

Fern Walk Along the Mon River Rail-Trail
June 30th at 9:30 am

The Mon River Rail-Trail offers many opportunities for nature study, whether it be bird watching, general botanizing, tree hugging, or, my personal favorite, enjoying the beauty and diversity of the ferns.

Below you will find some information on ferns that includes reproduction and morphology, along with line drawings of the ferns we will see today. Unless otherwise noted, the line drawings by James C. W. Chen are from the classic fern book "The Fern Guide" by Edgar T. Wherry, first published in 1937 and last published, with major updates, in 1961.

Source: Northeast Ferns, Second Edition by Steve W Chadde

The drawing above will be helpful in understanding what parts of a fern are where, what their function is, and as an aid in identification. Take note of the rhizome and the sorus; these are two of the ways a fern reproduces or spreads.

 

How Ferns Reproduce
Sex or No Sex?

Ferns are non-flowering vascular plants that reproduce both vegetatively and by spores. Many ferns have creeping or dividing rhizomes that allow the plant to spread, sometimes forming large colonies. This simple process can be thought of as a risk-free method of propagation.

When ferns reproduce by spores, the process is more complicated and not without risks. The spores are contained in structures called sporangia that have a unique method of dispersing the spores. The sporangia are contained in sori, which can be seen as dots on the back of the fern leaf. The sori are covered by an indusium, which helps to protect the sporangia. When the time is right the spores are catapulted into the air by the sporangia.

If the spores land in a favorable spot, the spore germinates and then forms a structure called a prothallus or gametophyte. The prothallus produces eggs and sperm. When fertilization takes place, a fern is born.

Life Cycle of a Fern
The Alternation of Generations

Source: © Merriam-Webster Inc.

Ferns reproduce through the alternation of generations, a process that requires two generations of plants to complete the fern's life cycle.

On the left side of this illustration, we see the leafy fern frond we are most familiar with. This is the non-sexual stage. This generation produces spores that germinate to produce the gametaphyte. The gametophyte is the sexual phase in the life cycle of a fern, having both male (antheridium) and female (archegonium) organs. When the antheridium is mature, it releases sperm that swim through a film of water to the archegonium and fertilize the egg. When germination occurs, a fern is born, thus begins the non-sexual stage. The fern grows and matures, then produces spores, and the cycle starts again.

Source: © 2024 RBG Edinburgh

The sori are the greenish dots that are covered with an indusium. The indusium helps to protect the sporangia and control spore dispersal.

Source: HardyFernLibrary.com

Here we see the sorus and the slightly shrunken indusium. The sporangia that contain the spores can be seen as what look like black beads.

Source: Ferns: A Natural History by Edward Frankel (Author), Edgar M. Paulton (Illustrator)

Soon the spores in the sporangia shown above will be flung out into another world.

Source: Margaret Slosson - 1906

The fern sporangium: a unique catapult.

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Fern Identification
Now the Fun Begins

Ferns are relatively easy to identify by their overall shape and size. Other characteristics, such as the presence or absence of scales and minute stalked glands, can help in identification, as can the shape and position of the sorus and the indusium (or lack thereof). The sorus (see above) may be protected during development by a scale or flap of tissue called an indusium. Below are some examples of sori with and without an indusium and examples of various frond shapes.

Source: Ferns: A Natural History by Edward Frankel (Author), Edgar M. Paulton (Illustrator)

Source: ©2024 The Hardy Fern Foundation

Frond shape and size are important in identifying ferns.

 

Now, let's take a look at the ferns we will see along the Rail-Trail. They are shown here in order of appearance.

Bead (Sensitive) fern
Onoclea sensibilis

Bead (Sensitive) fern
Onoclea sensibilis

Up to 30", commonly 16-24" ⋄ Indusia: absent

Some ferns have dimorphic fronds, as does the Bead fern: one frond is non-spore-bearing (sterile), and the other is spore-bearing (fertile). In the case of the Bead fern, the fertile frond emerges green in color, and when the spores are discharged, it turns dark brown and woody. These now-woody, fertile fronds persist through the winter and are sometimes seen poking up through the snow. Although many spores are produced, the primary way the Bead fern spreads is through a creeping rhizome, sometimes forming large colonies. 

Common Horsetail
Equisetum arvense

Fertile stems to 10”, commonly 5-10" ⋄ Sterile stems to 24", commonly 10-16" ⋄ Indusia: absent

This un-fern-like plant often grows in disturbed and waste areas and can sometimes be seen pushing forth through cinders and rail-road ballast. But the Common Horsetail can also be found on the edges of woods. The fertile stem, with its cone-like structure containing the spores, emerges first in early spring. Often, the fertile stem is nowhere to be found by the time the sterile stem has emerged and expanded. The plants have an extensive underground system of jointed rootstocks bearing roots at the nodes. (See illustration above.) 

Hay-scented fern
Dennstaedtia punctilobula

Up to 3', commonly 18-24" ⋄ Indusia: cup shaped

The Hay-scented fern belies its delicate appearance and can be found growing in full sun or dense shade. It sometimes grows atop boulders in full, blazing sun, and this has earned it one of its common names: "Boulder fern." It is a vigorous plant that spreads rapidly from its slender, long, creeping, and branching rootstock and will sometimes cover miles of woodland utility corridors, often growing in the company of the New York fern.
If you find a fern with a stipe shorter than the blade that is also shining red brown, grades into a yellow-brown rachis, and has copious gland-tipped white hairs, then you have found the Hay-scented fern. And does it have the scent of hay? You decide.

Christmas fern
Polystichum acrostichoides

Up to 3', commonly 18-24" ⋄  Dimorphic ⋄ Indusia: round and umbrella like

The dimorphic fronds of this easily recognized but highly variable fern take their common name from the association of the auricled (eared) pinnae resembling Christmas stockings as well as being a prominent woodland plant in the winter landscape. The silvery fiddleheads emerge in early spring. It is certainly the most widespread and common of all our ferns.

New York fern
Amauropelta noveboracensis

Up to 2’, commonly 12-18”  ⋄ Indusium: notched and may be hairy

The New York fern grows in both sun and shade, and like the Hay-Scented fern, it will colonize large areas. No other common West Virginia fern has the lower pinnae so reduced in size. The fronds tapers both ways—a very convenient identification mark. The fronds wither and yellow with the first frosts, making it easy to spot this species in the fall of the year.

Spinulose Wood fern
Dryopteris carthusiana

Up to 30", commonly 12-24" ⋄ Indusium: kidney shaped and free of glands. ⋄ Partially evergreen

The Spinulose Wood fern and the Evergreen Wood fern (see below) are very similar in shape and size. The most reliable way to differentiate the two is by looking closely at the first and second pinnules of the bottom pinnae. If the innermost pinnule is the longest, it is the Spinulose Wood fern (see above). If the second pinnule is the longest, it is Evergreen Wood fern (see below). If a hand lens is available, a close inspection will reveal the absence of stalked glands on the Spinulose Wood fern, while the Evergreen Wood fern has stalked glands on the indusia, stipe, and rachis.

Evergreen Wood fern
Drypopteris intermedia

Up to 30", commonly 18-24" ⋄ Indusia: kidney shaped with stalked glands ⋄ Evergreen

This lacy, evergreen fern is superficially similar in appearance to the Spinulose Wood fern but with a lighter and more uniform green color. Sometimes, plant growing side-by-side will be confusing to some beginners. Generally, the second set of pinnules on the lowest pinna is the longest. A hand lens for viewing the stalked glands that are present on the indusia will be helpful in identification. The Spinulose Wood fern lacks these glands.

Marginal Wood fern
Dryopteris marginalis

Up to 3', commonly 12-24" ⋄ Indusia: kidney shaped, close to margin ⋄ Evergreen

The leathery, grey-green fronds of the Marginal Wood fern make it stand out wherever it grows. And, if you find a fertile frond, you will see the sori closely placed along the margin of the pinnae, thus the common name of Marginal Wood fern. This characteristic, in addition to the yellow-brown scales covering the stipe, will help with identification.

Broad Beech fern
Phegopteris hexagonoptera

Up to 24", commonly 6-12" ⋄ Indusia: absent

This distinctive-looking fern has erect, triangular-shaped fronds arising from a branched and creeping rhizome growing at or below the ground. The fronds are usually broader than long, and the rachis is winged down to the lowest pair of pinnae. The bottom pair of pinnae are the largest and point downward and out. The sori are round and without an indusium. Found in open woods of various soil types. The Broad Beech fern tolerates dry conditions and looks fresh throughout the growing season.

Southern Lady-fern
Athyrium asplenioides

Up to 3', commonly 14-18" ⋄ Indusia: linear, curved

This fern can be difficult for the fern novice to identify as it is highly variable in appearance over its range and is easily confused with the superficially similar Evergreen Wood fern and the Hay-scented fern. The stipes are green, straw-colored, brown, or reddish. The stipe and rachis have a deep and noticeable groove on top.

Silvery Glade fern
Deparia acrostichoides

Up to 3', commonly 18-24" ⋄ Indusia: linear and silvery-white

The Silvery Glade fern somewhat resembles the New York fern since the fronds tend to taper at the base, but the Silvery Glade fern is a much larger and coarser fern as well as having linear sori. The fertile leaves bear sori on the underside of the leaves and are silvery green at first but later become light brown as they mature. It often forms extensive colonies, growing from a creeping rootstock. The fertile fronds tend to be more erect and upright than the sterile fronds.

Photo: Mike Breiding

Narrow-leaved Glade fern
Homalosorus pycnocarpos

Up to 3', commonly 18-24" ⋄ Indusia: linear, along veins, slightly curved

The Narrow-leaved Glade fern is sometimes mistaken for the Christmas fern, a species that it superficially resembles. The lack of auricles and the fact that this species is not evergreen will distinguish the two very quickly.
The Narrow-leaved Glade fern may form large colonies, but it is most commonly seen as dense clumps. The fertile fronds that bear the linear sori are significantly more upright and erect than the sterile fronds.

Interrupted fern
Claytosmunda claytoniana

Up to 4', commonly 24-30" ⋄ Indusia: Absent

This large, luxuriant fern has fronds arising from a heavy, fibrous crown and can live to be over 100 years old. The Interrupted fern is semi-dimorphic and has both fertile and sterile pinna on the same blade. When mature, the fertile pinnae turn brown, wither, and drop off, leaving the blade with an "interruption".
The Interrupted fern and its "cousin," the Cinnamon fern (Osmundastrum cinnamomeum) are similar in shape and size. However, the Cinnamon fern has fertile fronds resembling cinnamon sticks and cinnamon-colored woolly tufts at the base of the pinnae.

Northern Maidenhair fern
Adiantum pedatum

Up to 2’, commonly 16-20" ⋄ Indusia: false - reflexed margin of pinnule

Another un-fern-like fern, the Northern Maidenhair’s delicate fronds, with dark, shiny stems, spread their pinnae horizontally in a nearly perfect circle. This graceful, fan-like pattern is unique among native ferns. Each leaflet has many very small pinnules, contributing to the dainty appearance of the plant. Like other ferns in the genus, the name maidenhair refers to the slender, shining black stipes.

Reflexed indusium of Maiden-hair fern(Adiantum pedatum).

Photo: Mike Breiding

Maiden-hair fern (Adiantum pedatum) in a woodland setting.

Photo: Mike Breiding

Up to 7’, commonly 2-3’  ⋄ Indusia: false - reflexed margin of pinnule

The largest of West Virginia ferns, sometimes reaching a height of seven feet or more. Often grows in disturbed are such as roadsides, rail road corridors and area with sandy and acidic soils. The sori are marginal, running in a continuous line under a false indusium created by inrolling of the leaf margin.
The word bracken is of Old Norse origin, related to Swedish bräken and Danish bregne, both meaning fern.
The Bracken fern is found on all continents except Antarctica and in all environments except deserts.

Rattlesnake Grape fern
Botrypus virginianus

Up to 30", commonly 10-16", ⋄ Indusia: absent ⋄ Dimorphic

This un-fern-like fern can be tricky to spot as there are several flowering plants that look similar, one being sweet cicely.
The Rattlesnake Grape fern has bright green, thinly textured fronds that appear early in the spring. The fertile part of the frond arises from the same point as the sterile parts. The fertile spikes bearing sporangia are thought to resemble the rattles of a rattlesnake or cluster of grapes. Interestingly, all plants of this species are fertile, although this is not always obvious. Upon close inspection, plants appearing to be sterile will have a tiny and stunted fertile frond at the base of the first pinna.

Goldie's Wood fern
Dryopteris goldieana

Source: The Pteridophytes of West Virginia: West Virginia University Studies, Series 39, No. 2, August, 1938
by Maurice G Brooks (Author), Abraham Stanley Margolin (Illustrator)

Up to 4’, commonly 2-3' ⋄ Indusia: kidney shaped

The largest of the wood ferns is distinguished by its large size and backward-arching, oblong-triangular, dark green (sometimes golden-green) fronds, which taper abruptly near the tip. The grooved stipe is quite long, forming 1/3 the length of the frond. The scales of the stipe are distinctive, being broad and tan brown with a dark center. Named for its discoverer, Scottish botanist John Goldie.

Photo: Mike Breiding

Tennessee Fragile fern
Cystopteris x tennesseensis

This interesting fern is a hybrid between the Southern Bladder fern (Cystopteris protrusa) and the Bulblet Bladder fern (Cystopteris bulbifera). The latter parent produces bulblets on the underside of the leaf which drop off and make new plants. This characterisitic is passed on to the Tennessee Fragile fern which occasioanally produces mishappen bulblets. Tennessee Fragile fern is usually epipetric - found growing on rocks.

Books About Ferns

The Ferns of Kentucky, published in 1878 by John Williamson, was the first book on ferns in the United States. This was followed by Frances Theodora Parsons' "How to Know the Ferns," published in 1899.

In March 2024, Emily Sessa's book "Ferns, Spikemosses, Clubmosses, and Quillworts of Eastern North America" was published. This is both the latest and greatest fern book. The book has keys, range maps, detailed color photographs, and facing-page species descriptions that aid exploration and allow reliable identification of all 305 species found in the area covered by the book—the United States east of the Mississippi and contiguous Canada, except for extreme northern and northeastern Canada.
This 525-page, two-pound volume is hardly a pocket guide, but if you have any interest in ferns, this book is a must-have. 

Here is a list of more portable fern guides. Some are out of print but a Google search will usually turn up used copies from various online sellers.

Field Guides:
Ferns & Allies of the North Woods by Joe Walewski
Northeast Ferns by Steve W. Chadde
Identifying Ferns the Easy Way by Lynn Levine
The Fern Guide by Edgar T Wherry
Ferns: Peterson Field Guides by Cobb/Farnsworth/Lowe
Fern Finder by Hallowell and Hallowell
Field Guide to Northeastern Ferns by Eugene Cecil Ogden

Fern Books of General Interest:
A Natural History of Ferns by Robbin Moran
Ferns to Know and Grow by F. Gordon Foster
A Fern is Born by J.M Guilcher and R. H. Noailles

Of Historical Interest:
Our Ferns in Their Haunts by Willard Clute
The Fern Lovers Companion by George Henry Tilton
Field Book of Common Ferns by Herbert Durand
Who's Who Among the Ferns by Wilma Beecroft

 

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