Ferns

 

Section Overview
Databases

Information Format

Overview of Ferns

Description of Ferns

 

Page Links

Inventory of Fern Families and Species

Botanical Glossary

 

Section Overview

 

There has been no systematic research conducted in Sky Meadows State
Park to identify ferns. Even though research was conducted in 2010 to
began the process of identifying various ferns inhabiting Sky Meadows,
further research will be necessary before an accurate and comprehen-
sive inventory of species is completed. Currently there are three species

of identified ferns from three fern families.

 

Databases

 

No database has been selected for information concerning fern species.
However, the United States Department of Agriculture's Fire Effects
Information System (FEIS) will probably provide the "core" database for
most species information as well as general entry structure. Additional
information from other sources will be "integrated" with the FEIS. Other
primary information sources may include:

 

PLANTS Database
USDA Forest Service

FDGIF (Virginia Department of Game and Inland Fisheries)
VDF (Virginia Department of Forestry)
American Fern Society
Wikipedia

 

Information Format

 

The general information format and fern entries that may be used will
probably be derived from the Fire Effects Information System (see
"Databases" section of website for discussion of FEIS). Some modifca-
tions in structure have will be employed. The following is a delineation
of the modified FEIS format that may be used.

 

CITATION: The common fern name(s) followed by the current scientific
nomenclature.
COMMON NAMES: List of generally accepted common names.
SCIENTIFIC SYNONYMS: Partial list of previously used scientific
nomenclature.
TAXONOMY: Current taxonomic classification with discussion of varities
or subspecies, as well as hybridization characteristics.
NATIVE STATUS: Includes information pertaining to whether the fern is
native or introduced as it occurs in the United States and Canada.
GENERAL BOTANICAL CHARACTERISTICS: Includes information
describing basic botanical characteristics (e.g., form, leaves, spores, etc.). REGENERATION PROCESSES: Regeneration from vegetative parts
and from spores.

HABITAT TYPES: General habitat types.
SITE CHARACTERISTICS: Includes information on topography, soil
types and elevations where species occurs.
SEASONAL DEVELOPMENT: Spore distribution time.
GENERAL DISTRIBUTION: The general North American (United States
and Canada) distrubution of fern species.
SKY MEADOWS DISTRIBUTION: Distribution of fern species within Sky
Meadows State Park.
HABITAT TYPES: General habitat types.
IMPORTANCE AND USES: Importance of fern species to wildlife and
livestock, value for rehabilitation of disturbed sites, consturuction material
and ornamental use, and any medicinal characteristics.

 

Overview of Ferns

 

A fern is any one of a group of about 12,000 species of plants. Unlike
mosses, they have xylem (one of the two types of transport tissue) and
phloem (the living tissue that carries organic nutrients, particularly
sucrose, a sugar, to all parts of the plant where needed). They have
stems, leaves, and roots like other vascular plants. Ferns do not have
either seeds or flowers (they reproduce via spores).

 

The stereotypic image of ferns growing in moist shady woodland nooks
is far from being a complete picture of the habitats where ferns can be
found growing. Fern species live in a wide variety of habitats, from
remote mountain elevations, to dry desert rock faces, to bodies of water
or in open fields. Ferns in general may be thought of as largely being
specialists in marginal habitats, often succeeding in places where various
environmental factors limit the success of flowering plants. Some ferns
are among the world's most serious weed species, including the bracken
fern growing in the British highlands, or the mosquito fern (Azolla)
growing in tropical lakes, both species forming large aggressively
spreading colonies. There are four particular types of habitats that
ferns are found in: moist, shady forests; crevices in rock faces,
especially when sheltered from the full sun; acid wetlands including
bogs and swamps; and tropical trees, where many species are
epiphytes (a plant that grows upon another plant non-parasitically or
sometimes upon some other object and derives its moisture and
nutrients from the air and rain and sometimes from debris
accumulating around it.

 

Ferns are not of major economic importance, but some are grown or
gathered for food, as ornamental plants, or for remediating contaminated
soils.

 

Description of Ferns

 

While most visitors to Sky Meadows State Park can identify some ferns,
they are usually not familiar with the different species and their life
cycles. The following discussion is from the Introduction section of the
American Fern Society's website (http://www.amerfernsoc.org/).

Introduction: Ferns have been with us for more than 300 million
years and in that time the diversification of their form has been
phenomenal. Ferns grow in many different habitats around the world.
The ferns were at their height during the Carboniferous Period (the
age of ferns) as they were the dominant part of the vegetation at that
time. During this era some fern like groups actually evolved seeds (the
seed ferns) making up perhaps half of the fern like foliage in Carbonifer-
ous forests and much later giving rise to the flowering plants. Most of the
ferns of the Carboniferous became extinct but some later evolved into
our modern ferns. There are about 12,000 species in the world today.

Ferns and fern-allies are more complicated in structure than most
people would suspect. Their structures, though similar in some ways
to those of flowering plants are different enough to warrant a distinctive
terminology (i.e., fronds, rhizomes, roots, sporangiia, and spores). Each
of these terms is examined below.

 

Fronds: The frond is the part of the fern that we see as we wander
through the woods it is the "leaf" of a fern. It is divided into two main
parts, the stipe (leaf stalk or petiole) and the blade (the leafy expanded
portion of the frond).

 

The blade may be undivided to finely cut, each degree of division having
a specific term. "Pinnate" blades are divided into leaflets (pinnae), with
each leaflet narrowly attached to the central stem (called the rachis in
this leafy part of the frond). Blades more divided are designated as
bipinnate or even tripinnate with some divided four or five times. The
ultimate division are called pinnules. Another type of division is one
where the green leafy tissue isn't completely separated from the rachis
but rather it spreads along the rachis, instead this degree of division is
called "pinnatifid".

 

Fronds vary greatly in size, from tree ferns with 12 foot fronds to the
mosquito ferns with fronds only 1/16 of an inch long.

 

Rhizomes: Rhizomes would be comparable to "stems" in the flowering
plants. Frondsarise from the rhizome. In many cases the rhizome can be
inconspicuous or even entirely underground. Rhizomes of tree ferns on
the other hand may be 60cm in diameter and up to 12 m tall. In some
epiphytic ferns (ferns that grow in trees) and in terrestrial creeping ferns
the rhizome roams widely and is quite visible. The fronds that arise from
this "stem" arise from the upper side or occur in one or more rows laterally
on each side. The rhizome contains the conducting tissues (xylem and
phloem) and the strengthening tissues (sclerenchyma fibers). The conduct-
ing tissue, known as the vascular bundle, carries the water, minerals, and
nutrients throughout the plant.

 

Roots: Roots are formed from the rhizomes or sometimes from the stipe.
The roots usually do not divide once they grow from the rhizome. Tree fern
roots grow down from the crown and help thicken and strengthen the
trunk. The roots anchor the plant to the ground and absorb water and
minerals.

 

Sporangiia: The Sporangia are the reproductive structures of the ferns
and fern allies. They are miniature sacks or capsules that produce the
dustlike spores that are the "seeds" by which ferns are propagated.
Several sporangia grouped together are called a Sorus. The arrangement
of sporangia varies greatly in ferns. Most ferns that we would see as we
walk through the forest would have their sporangia on the underside of
the frond, arranged in an organized pattern usually associated with veins
in the pinnule (leaf). Many times (but not always) the ferns provide a
protective covering for the sorus called an indusium.

 

Spores: The "seeds" of the ferns and fern allies are called Spores.
Normally they are formed in groups of four. Spores contain oil droplets
and sometimes chlorophyll in addition to their nucleus. Ferns drop millions,
often times billions of spores during their lifetime but very few ever land in
a spot suitable for growth.

 

The life cycle of the ferns may seem complicated but it has worked quite
successfully for millions of years. Though spores come from fronds of
ferns, the fronds do not come directly from the spores. Spores from the
parent fall to the ground and with an enormous amount of luck (millions
perish for every success) they will find suitable moisture and light. The
tiny single-celled organism starts to grow by cell division. Soon orderly
arrangements of cells form little green heart shaped plants or Prothallia

(gametophytes). These plants go unnoticed by most people as they are
only 1/2 inch or less across and lie flat on the ground. This is an
independent plant with its own simple "root" system (rhizoids) to
provide it with nutrients and water.

 

The prothallium then grows antheridia or male organs and archegonia or
female organs on its underside. The antheridium produces spermatazoids
(or antherozoids) which will swim via a droplet of water to the egg
produced by the archegonium. The fertilized egg then begins to grow the
sporophyte, the plant that we know as a fern (although this is the primary
form of propagation, there are several other ways that ferns procreate).

 

 

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