A Note of Caution

An appendix to The Sierra Club Guide to Natural Areas in and around Iowa City


Iowa's outdoors is frequently beautiful, but it is not without its hazards, both natural and manmade. No guidebook to Iowa's outdoors can hope to cover all of the hazards, but some are so pervasive that it would be irresponsible not to discuss them.

Hazardous Plants

Poison Ivy
Leaves of three, let it be! Poison ivy is common throughout Iowa's woodlands and scrublands. It grows as a vine, climbing trees and rock faces; mature vines sometimes reach diameters of 4 inches. Poison ivy also grows as a bush, reaching heights of 5 to 8 feet, and as a low groundcover, creeping into prairie areas.

The toxin in poison ivy is an oily resin that is contained within the plant tissue. The toxin may not be present on the surface of undamaged leaves, but any time the plant tissue is broken, for example, by crushing leaves or breaking twigs, the toxin is exposed. Washing with soap and water after exposure is generally sufficient to remove the toxin; if this is done sufficiently quickly, an alergic reaction may be avoided.

Some people do not react to poison ivy, but this should not be seen as a sign of immunity! The reaction to poison ivy is an alergic reaction, and like many alergic reactions, exposure to sufficient doses of the toxin may sensitise a person who has previously not shown any sensitivity. If you believe you have been exposed, wash it off!

Not all three-leaved plants are poison ivy! The most common plants that are mistaken for poison ivy are boxelder saplings. These sometimes have leaf forms that are almost identical to those of poison ivy, but the leaves are a lighter shade of green, and more importantly, most boxelder saplings also have some leaves with 5 or 7 leaflets, while poison ivy always has 3 leaflets per leaf.

Another poison ivy mimic is fragrant sumac. This is actually a close relative, but it grows as dense low clumps in open prairie remnants and is both harmless and a desirable member of the prairie biota. The leaves are generally smaller than those of poison ivy, but the major diagnostic is habitat. Poison ivy is a woodland and scrub plant that rarely thrives in wide open areas.

Wild Parsnip
This european import is a common weed in dusturbed areas, including barnyards, pastures and roadsides. It is a member of the carrot family, with a bloom that is similar to that of the common wild carrot, Queen Anne's lace, but larger and yellowish green colored.

All of the green parts of the wild parsnip plant contain a toxin that immensely magnifies the effects of ultraviolet light on skin. This toxin is concentrated in the flowers, and when the flowers are in full bloom, the toxin is present in the dewdrops exuded from the blossoms. Immediate washing after contact may be of some value, but once the toxin soaks into the skin, serious sunburn of the exposed area is almost inevitable. The resulting burns are frequently circular or crescent shaped, mirroring the shape of the parsnip blossom that caused them.

Once sensitized by the toxin, the skin remains extremely sensitive to ultraviolet light for weeks. The only cure is to completely shield the exposed areas from light. After exposure, even the minor ultraviolet emmissions of indoor fluorescent lighting fixture may cause discomfort.

Stinging Nettles
The stinging nettle is common in disturbed most soil with partial to full sun. It grows to a height of 4 to 6 feet. The hairs on the nettle leaves and stems are hollow, and contain histamine. Brushing against the plant causes a red rash and an immediate sensation varying from an intense itch to agonizing pain. Fortunately, both the sensation and the rash pass a matter of minutes. Long pants and long sleeved shirts are the best defense.

Thorns and Brambles
Iowa is home to many thorny plants, ranging from the relatively innocuous thorns of raspberries and blackberries to the perverse thorns of the black locust tree and the multiflora rose. It is also worth noting the razor sharp microscopic fuzz of the hop vine, a common vine of disturbed areas.

If you intend to walk off-trail anywhere in Iowa, be prepared for thorns. Lightweight walking shorts and walking sandals may be more comfortable in the heat of summer, but they provide little or no protection. Long pants and heavy boots are the best defense.

Hazardous Bugs

Several species of ticks are found in Iowa, including the common dog tick, the wood tick, and the black-legged tick, previously known as the deer tick. The latter has gained notoriety as a carrier of Lyme disease, but there is evidence that any tick that has bitten an infected animal may transmit the borrelia bacteria that causes Lyme disease.

Ticks are typically active whenever insects are active. Ticks tend to crawl uphill until they find cover, and then, when they feel secure, they dig their heads into the skin and begin their meal of blood. To a tick, hair is secure, areas where clothing is snug and does not chafe are secure, and bare skin is not. As a result, ticks frequently hold off on starting their meals until they reach a person's crotch, armpit, beltline or hairline. Under the hair at the back of the neck is a particularly snug place, from a ticks point of view.

The first line of defense against ticks is clothing. Pants tucked into boot tops and shirts tucked into pants will keep a tick crawling upward from finding skin until it reaches your shirt collar. If you're lucky, you'll accidentally brush the tick off before it reaches your hair. There are also reports that nudists are less likely to pick up ticks than those of us who wear clothing, perhaps because large expanses of bare skin are not comfortable places for ticks.

The second line of defense against ticks is bathing and inspection. Ticks don't rush to do anything, and they frequently don't begin their meal until they've been riding on a person for some time. Inspecting for the smaller ticks is difficult, but showering, shampooing and combing your hair are highly likely to remove ticks that have not started their meals.

If you do find a tick that has begun its meal, remove it. The most common advice is to simply grasp the tick as close to the skin as possible, using fine pointed tweezers to avoid squeezing its gut, and then gently and firmly pull until it lets go. Quickly ripping the tick out risks leaving its head embedded in the skin, and anything that causes the tick to regurgitate risks an increased chance of infection with any diseases the tick happens to carry. Once the tick is removed, disinfect the site of the tick bite.

It is prudent to save the tick (refrigeration in a ziploc bag with a few blades of grass) and make a note of where and when it bit you and where you think you picked up the tick. Ticks can be tested for several tick born diseases at the University of Iowa Hygenic Lab, and the lab collects statistical information on the distribution of ticks and the diseases they carry.

Yes, there are mosquitos in Iowa. Insect repellants containing DEET work well, and there are unproven folk remidies such as Avon's Skin So Soft that some people swear by.

Bees and Wasps
Yes, there are also bees and wasps in Iowa. Leave them alone and they'll ignore you. If you wear bright floral colors, particularly red, you'll sometimes find yourself attracting bumblebees, but after each bee takes the time to discover you're not a flower, it'll go away.

Bees and wasps pose their biggest threat to those who accidently disturb a hive. Be careful around hollow trees, rock shelters, and other places that may provide a snug home for a colony.

Hazardous Animals

Without any question, people are the most hazardous animals found in Iowa. There is nothing quite as disquieting as being confronted by a gun-toting landowner when you thought you were on a public hiking trail. This guide doesn't point at any areas where there are known disputes over land ownership, but that doesn't guarantee that you won't run into strange and possibly dangerous people.

There are many varieties of snakes in Iowa, and a few are poisonous, the timber, prairie and massasauga rattlesnakes, and the copperhead. The paririe and massasauga rattlers and the copperhead are endangered species, and all are rare enough in Iowa that the DNR would like reports of any that you encounter. The timber and massasauga rattlesnakes are the only ones likely to be found in east central Iowa, the former in wooded areas where there are rock outcrops, the latter near low swampy ground. As poisonous snakes go, they are not particularly threatening; the last fatality from a bite by a timber rattle snake was in the 1880s!

If you are lucky enough to see a rattlesnake, treat it with respect and brag about it and tell the DNR. Most of us who frequent Iowa's outdoors have never seen one! See http://www.herpnet.net/ for more information.