June 1, 2020
The rattlesnakes have emerged, but there is no need to worry!
Every spring we watch for the several large timber rattlers that sun
themselves on a big rock down the road, while others take up temporary
residence under piles of drying lumber in one of the solar kilns.
The truth is that only one human fatality has resulted from timber
rattlesnake venom across its entire range during the past century, and
only two or three bites are reported each decade. We also understand
that less than half of all bites to humans by poisonous snakes contain
venom, as rattlesnakes can control the amounts injected when biting. We
treat our rattlesnakes with considerable respect, but find them to be
interesting and relatively docile neighbors despite their forbidding
Wisconsin has two poisonous snake species, the massasauga and the
timber rattler but only the timber rattlesnake lives among our rugged
open bluffs of southwestern Wisconsin. It is a heavy-bodied snake
with a broad triangular head, a narrow neck and a thick black tail
tipped with a tan rattle. Adults average about 40 inches in total
length and have dark cross bands extending along yellow, brown or
rust-orange backs. Fear and misunderstanding has resulted in many being
killed, which is the primary reason that it is listed as a protected
The timber rattlesnake feeds primarily on small mammals and typically
coils alongside a trail and waits for prey to come to it. The
snake's heat-sensing pits, located between the eye and the nostril on
each side of the face, warn of an approaching rodent., and snake bites
it injecting venom that kills it almost immediately, and then swallows
it whole. Timber rattlesnakes breed near the den site before moving
into the woods for the summer. A female often mates only a
few times during her life, requiring at least seven years to become
sexually mature and then reproducing only every third or so year.
In Wisconsin, litters of 6-15 young are born from late August to
mid-September but their mortality is high.
Snakes appeared in the fossil record 100 million years ago and vipers
evolved during the Miocene period, some 35 million years ago, and they
are not the only organisms at the farm that have ancient predecessors.
Long before dinosaurs walked the earth, there were horsetails. Perhaps
you have never noticed this rather unassuming plant, but it is found
locally in swampy areas, heavy soil, in ditches, and along the edges of
farm fields. Fertile stems emerge first, resembling jointed, leafless
tubes and topped by a yellowish, club-shaped, spore-bearing head. The
green, sterile shoots develop later, by which time the fertile stems
usually have wilted. These are jointed, hollow shoots, bearing up to 20
whorls of slender branches with insignificant leaves, and terminating
in a long, naked point. Common horsetail grows a foot or two tall while
giant horsetail may stretch up to seven feet. A major problem is its
far-ranging root system that produces thick stands of shoots that can
choke out other plants.
Horsetail is a plant left over from prehistoric times when it grew to
the size of our present-day fir trees and there were huge forests full
of them. It does not flower but reproduces from spores, as do ferns.
The whole plant has a hard grainy texture, and when crumpled in the
hands makes a good scour, like fine-texture sandpaper. In the Middle
Ages it was used as an abrasive by cabinetmakers, to clean pewter,
brass, and copper, and for scouring wood containers and milk pans.
Some people cook and eat the young fertile shoots as a sort of
asparagus substitute, but this seems risky as livestock have been
poisoned by consuming the gritty weed. It is an interesting fact that
horsetail picks up compounds such as selenium, mercury and gold from
the soil in which it grows. In some areas, it has been found to
accumulate up to 4.5 ounces of gold per ton of fresh plant material,
but its value is primarily as an indicator plant rather than as a
commercial source of gold. Early Romans wrote of using the plant to
staunch bleeding in wounds, and at various times it was even employed
as a folk remedy for kidney and bladder troubles, arthritis, bleeding
ulcers, and tuberculosis.
There are other primitive plants in our woods and fields. One is
lichen, which consists of two life forms, a green algae or blue-green
bacteria that is photosynthetic, and a fungus. Others are liverworts
and moss that lack true roots and must absorb water and nutrients
through their surfaces. Club moss, which is not a true moss, also had
ancient predecessors that included giant tree-sized plants and
contributed to the coal deposits then being formed.
Ferns were known to live as early as 300 million years ago, and cone
bearing plants, which today include pine, cypress, spruce, cedar,
juniper, and redwood, were more diverse when dinosaurs roamed the
earth. A fern does not have stems but the leaves arise directly
from a below ground rhizome or very short vertical stem near the soil
surface. Those in Wisconsin may be as small as one inch long, or as
large as three feet long in other species and most die back at the end
of each growing season while the stem overwinters below the soil
surface. The frond may be undivided divided into smaller parts and
perhaps each part is again divided, etc. Ferns do not produce
flowers or seeds, but rather reproduce by spores, minute,
typically one-celled, reproductive units capable of giving rise to new
individuals without sexual fusion.
The structures of all these plants have changed little through the
centuries, and our woods and hills are full of organisms-- both animal
and plant--that are fascinating in their diversity.