Pteridium aquilinum
Markku Savela
Bracken is a large
fern,
sometimes growing over three feet tall. Instead of the usual
leaves, ferns have fronds,
made up of smaller leaflets
(groups of mini-leaves) with small pinnae
(tiny mini-leaves) on them. Bracken fronds are shaped
like triangles. Each frond usually has three
leaflets. Bracken grow in large
colonies in fields, brushy areas, and woods. They have thick
root-like stems, called rhizomes,
underground. Rhizomes can grow six feet long, and many
fronds may grow from one rhizome. Each rhizome also has
tiny, hair-like, black roots on it. Each winter, Bracken's
fronds die with the frost and fall to the ground. New fronds
will grow the following Spring. Bracken Ferns can
reproduce
two ways. One is by rhizomes spreading, and the other is by
spores.
Ferns do not have flowers like most plants. Instead, on the
underside of the fronds, there are small objects, called
sori.
The sori produce spores, which are a lot like seeds from a
flowering plant. Spores travel by wind and
grow new ferns in new places. Bracken Ferns often grow
under oaks, pines, hickories, maples, and beech trees. They
are frequently seen growing with violets, oak fern,
bunchberry, asters, sarsparilla, and other
plants. Bracken Ferns help some
plants grow, and hurt others. They are allelopathic
to some plants, which means they let out chemicals that keep
them from growing. Black Cherry trees are one plant that has
trouble growing around Bracken Ferns. Other plants are helped
by Bracken. Because Bracken Ferns grown in thick colonies,
they can hide small tree seedlings and other plants that
might be eaten by animals. Young Bracken Ferns are
eaten in the Spring by White-tailed Deer. Rabbits will also
eat fronds. Many animals and insects won't eat Bracken
because of chemicals in it that make them sick. There are
several species of insects, including sawflies and some
caterpillars, which eat Bracken. Many of these caterpillars
were introduced from Europe.
