The excellent, 462-page Plants of Southern Interior British Columbia (ISBN #1-55105-057-9), lists some 700 species of plants; a comprehensive overview of the entire Okanagan ecosystem is obviously far beyond the scope of the book or this website - it would fill volumes!  I am however going to describe a couple of the most common plants and insects that you are sure to encounter in the area; those being the ones that you should afford a wide berth.

One of the side-effects of spending a lot great deal of time in the outdoors is that one inevitably comes in contact with plants and critters that are highly defensive. I’ve experienced my share of unsavory encounters with ivy, nettle, wood-ticks and thorns as a youth and have oftentimes seen the plants and insects described below in the Okanagan Valley.  Consider this a “read it for your own good” chapter as you will likely come in contact with one or more of the scourges listed below as you make your way along the valley's sweet singletrack!

Poison Ivy Grows throughout much of North America, including all Canadian provinces except Newfoundland. It’s generally found in wooded areas, especially, but not limited to, the edge of forest cover, as its only somewhat shade tolerant. The plant rarely grows at altitudes above 1,500 meters and is a plant-chameleon; appearing as a shrub up to 1.2 meters in height, as ground-cover 10–25 centimeters high, or rarely, as a climbing vine. The leaves appear as three almond-shaped leaflets and the berries are grayish-white in color. Poison ivy leaves range in color depending on, among other thing, the season.

They appear reddish-green to light-green in adolescence, uniformly dark green mid-summer, turning bright red in the autumn. The leaflets on mature plants are generally shiny and smooth, 3-12 cm long with few to no teeth along its edge. The plants three characteristics:

• Clusters of three leaflets

• Alternating leaf - stems

• Lack of jagged edges or thorns

...are sufficient to positively identify the plant.  Be aware that it may appear slightly different from the image included in this chapter during its May to July flowering season, as well as during August to November when it bears fruit.

Young Box Elder Maples, a common plant in this area, are often confused with Poison ivy, as these maples sometimes appear with three leaflets. The two can be differentiated through a closer visual inspection: observe where the small stems that the three leaflets are attached to, meet the main stalk. Another stem, more or less on the opposite side of the stalk is a characteristic of the Box Elder Maple. If however, the three-leaflet stems alternate along the main stalk, it’s likely Poison-ivy.

The reaction caused by contact with poison-ivy is technically known as a urushiol-induced contact dermatitis; an allergic reaction.  Approximately 15% of people have no allergic response to the plant, however most will become sensitized over time and with repeated or concentrated exposure.  Reactions that worsen over time may progress to anaphylaxis; a dangerous if not life-threatening condition. Those affected by urushiol experience a severely irritating itch and rash, and in extreme cases, corticosteroids may be needed as treatment.

Urushiol oil penetrates the top layer of skin and binds to cells deep in the epidermis.  Nearly any soap will remove urushiol oil from the skin prior to bonding, the problem is that bonding takes place in a brief timeframe; between 2 and 30 minutes, depending on your skin type or what may already be on your skin. Once it bonds, it becomes extremely difficult, if not impossible to remove.  Unfortunately, most people don't know that they've been affected by urushiol oil until its too late and the itching / rash has already begun to develop; by then, preventative maintenance becomes practically useless.

This itch eventually develops into a reddish inflammation or colorless bumps, followed by blistering of the skin. In severe cases, clear fluids may ooze from open blisters.  The appearance of a slowly spreading rash may indicate that some areas of the body received more direct contact with the poison and reacted sooner than adjacent areas.  It may also indicate that contamination is still occurring from contact with objects to which the original poison was spread; including clothing, camp bedding or your pet's fur.

Blisters and oozing fluids are a result of blood vessels that develop gaps and leak fluid through the skin; if the affected area is cooled, the vessels constrict and leak less.  Be aware that if poison ivy leaves are burned and the smoke inhaled, this same type of rash will affect the lining of the lungs, causing extreme pain and possibly fatal respiratory difficulty.

If consumed internally, the digestive tract, airway, kidneys or other organs can be damaged by the urushiol.  If treated, the rash and its affects my only last two weeks, while untreated exposures may persist as long as four weeks.  The plant’s oil can remain active for up to three years, thus handling dead leaves or vines can trigger an outbreak of lesions.

If you have been affected, here are a few things you can try.  Realize that I’m certainly not a health professional, so if you have no recollection of coming in contact with Poison ivy, or are suspicious in any way about what may be affecting you; please call a doctor before trying any of these techniques.

Most people find that cool compresses, such as a towel soaked in cold water, helps to relieve the intense itching.  This cools the skin and helps to compress the blood vessels, which reduces itching and production of the eventual surface mucus associated with poison ivy contact.  Soaking in a cool bathtub of water is also soothing, augmented by a gentle after-soak application of one of Aveeno’s anti-itch products  This company offers several lotions that are specific to poison ivy / poison oak rashes.  I’m also aware of a product marketed under the trade name Zanfel, which claims that it is able to remove urushiol, the toxin responsible for the reaction, from the skin, after bonding.  I’ve never had the urge to rub poison ivy leaves on my skin in order to verify their claims, so cannot say if it’s accurate.

Benadryl, taken in the evening, will make one drowsy and assist with sleep through the night, without the discomfort of awakening to the incessant itching.  The goal of a reduction in the itching is brought about by three things;

• Cooling by restricting the blood vessels

• Drying the rash

• Suppression of the body’s allergic response

In severe cases of poison ivy exposure, it’s a good idea to see a doctor. If you suspect that you may be re-affected due to unavoidable proximity to the plant, use products such as Stokogard Outdoor Cream and Hollister Moisture Barrier. Of seven products tested by the Department of Medicine, Duke University Medical Center, in randomized double-blind evaluations, these two proved to be most effective by a significant margin.

Stinging Nettles are a perennial, growing between one and two meters tall in the summer, dying back to ground-level in the winter and often found growing in masses.  Of the five varieties of stinging nettle found around the world, BC hosts two; American stinging nettle and the Hairy nettle.  Stinging nettles are generally found in disturbed soils and can be encountered on roadsides, but because they prefer nitrogen-rich soils, they tend to appear most often at garden or field border areas.  Symptoms resulting from a brush with stinging nettles include a burning sensation just after contact, followed by an itchy rash.

Culinary uses exist for stinging nettles: as they’ve long been consumed by aficionados of edible weeds who harvest the young leaves from and boil them, rendering the leaves edible.  Young leaves haven't had time yet to develop barbs on the leaves; not only will they not sting your mouth once cooked sufficiently, but young stinging nettle leaves are also quite nutritious.

It’s hairy green leaves range between 3 and 15 centimeters long and are borne opposite each other on a wiry stem. Their tips break off when touched, transforming the hairs into needles which, depending on the particular strain of plant, inject acetylcholine, histamine, 5-HT, serotonin and formic acid into whatever brushes up against it. 

This mix of chemicals causes a stinging sensation from which the species derives its name. Some of these chemicals are also found in certain species of ants

The effects of brushing up against the stinging nettle plant is felt almost immediately as an intense itching sensation.  The best way to deal with the problem is to resist the obvious urge to scratch the affected area, which will simply spread the chemicals and make matters worse.  Instead, attempt to wash the area as soon as possible using whatever means necessary; this simple action should remove most of the effect within minutes as, unlike the urushiol-effect of poison ivy, the sting of the nettle doesn’t bind with the skin so readily.

If you wish to be prepared for anything or are water-rationed, you can pack a lotion which contain antihistaminics or hydrocortisone which also provide relief from the symptoms of stinging nettle plants.  Aventis Pharma’s Anthisan cream appears to be the number one recommended relief agent.

Wood Ticks The arrival of spring weather brings with it the start of wood-tick season. Tick season usually peaks in spring and early summer; south facing slopes where the snow generally melts first, along with wildlife winter ranges feature the highest concentration of wood ticks. The Rocky Mountain Wood Tick is the most commonly found tick in our area and can transmit both Rocky Mountain spotted fever and Colorado tick fever.

Adult wood ticks measure approximately four to five millimeters in length and appear reddish brown in color, with a gray shield covering the front third of the females back.  Wood ticks bite into the skin and suck blood, sometimes enlarging to the size of a small grape, though one would have to be latched onto you for a long while in order to get that big.  I’ve been set upon by dozens of wood ticks in my life, and in every case was able to sense the insect was on me and remove it prior to it getting a firm purchase on my blood-supply.  One can generally feel it crawling around for a while before it hunkers down to feast.

The common mantra of “when possible avoid tick infested areas” is all but useless around the valley as they are to be found nearly everywhere, at most elevations.  As such, be alert for ticks by mentally monitoring yourself for the feeling of ‘something crawling on you’, scan yourself every time you stop for a break as well as after trail use.  Visually scan each other after arriving home as well; ticks are generally easy to spot.  Wear clothing that interfere with ticks attaching to the skin such as long sleeves that are tight at the wrist and tucked in at the waist, high boots and long pants that can be tucked into the boots or socks.  Light colored clothes also make the ticks more visible.

Avoid wearing shorts and short sleeve shirts unless the heat makes life unbearable.  Ticks denied physical attachment to the skin will not transmit disease.  Check your pets, as not only are they more prone to pick up ticks, but they can also pass them along to your home via their bedding areas. Ticks on your pets are obviously an undesirable situation for the animal.

Insect repellants containing DEET or permethrin can be applied to clothes to ward of wood ticks and insect repellants containing no more than 35% can be applied sparingly to exposed skin.  Do not apply DEET to children’s hands that are likely to come in contact with their eyes or mouth.  I’m not a big fan of DEET, I simply keep a sharp eye out for wood ticks every time I’m out in the woods.  I recommend that you research topical options for your pets, as thick fur oftentimes makes tick detection very difficult.

Remove wood ticks that have managed to latch onto you, your family or pets by first disinfecting the contact site with a dash of isopropyl alcohol or other appropriate disinfectant.  Next, grasp the tick as close to the skin as possible using a blunt curved forceps or tweezers and pull upward with a steady even pressure.  Be sure not to twist or jerk back on the insect as this may cause sections of the creature’s mouth to break off, leaving them in the skin and causing infection.

Furthermore, be extra-careful not to squeeze, crush or puncture the body of the tick as its fluids may contain infective agents.  After removing the tick, thoroughly disinfect the bite site, apply a bandage and wash your hands well. If you’re unable to remove the head of the tick, contact your health care provider as soon as possible.  Wood ticks can be disposed of by placing them in a container with isopropyl alcohol or flushing them down the toilet.

These diminutive little devils are capable of causing severe physical distress to the human body.  Tick paralysis occurs occasionally when the tick bite injects a toxin, with paralysis beginning within a five day period in the hands and feet, progressing to loss of coordination in the arms and legs.  Removal of the tick generally affords recovery within two days.

Rocky Mountain spotted fever is a very serious illness which can be transmitted by the bite of the Rocky Mountain Wood Tick.  Rocky Mountain spotted fever causes fever, fatigue, deep muscle pain, severe headaches, chills, and often a rash on the arms and legs. Illness occurs within as little as 72 hours or as long as two weeks following the tick bite.  There are no hard and cold facts to back this up; but its suggested that in order to transmit the disease, the wood tick must be attached (has submerged its head to feed) at least four hours or more.  Without treatment, up to fifteen percent of infected people may die, if diagnosed however, it is easily treated with antibiotics.

Colorado Tick Fever causes an onset of high fever four to five days following the tick bite.  This is followed by a brief remission, and then a second bout of fever lasting two to three days.  The wood tick doesn’t even have to be attached to its victim in order to transmit Colorado Tick Fever; a bite is sufficient.  The tick is usually found in the Western United States and Canada above 5,000 feet elevation.  Most people recover and there is no specific treatment, though many people believe that either wood tick bite causes long-term disabilities.

Lyme Disease is caused by the deer tick, an insect no larger than a poppy seed.  The deer tick is generally not found in the Okanagan, but while rare, some do exist here.  The tick must be attached for several hours to transmit disease and the most common indicator of Lyme disease is a bulls-eye rash at the site of the tick bite.  If it occurs see your health care provider for testing and treatment.  Anyone who develops signs of illness within 2 weeks after a tick bite should contact their physician or health care provider immediately so appropriate tests and medical treatment can begin.  Be sure to inform your physician that you were bitten by a tick and if you save the live tick bring it along for testing.

More information is available on the Canadian Lyme Disease website; canlyme.com. See also the discussions on DEET in the discussion of mosquitoes in the following pages.

Prickly Pear Cactus is found nearly everywhere in the South Okanagan valley, but especially on south-facing slopes as they favor a great deal of sunlight. Prickly pear cacti typically grow as smallish, rounded bases (platyclades), armed with large fixed spines and small, hair-like spines which can penetrate skin. They often grow in masses of perhaps a half-dozen plants.

Most of the cacti I’ve seen in the valley are of the low-growing, fairly innocuous, of the genus Cylindropuntia.  You may not notice them until you have one attached to you or your pet, but they have a way of making themselves noticed in no uncertain terms once attached.  You need to keep an eye open for them for several reasons, including your well-being, as well as your pets and you bicycle tires; all of which are easily attached to or punctured by this plant’s thorny spines.

Surprisingly, some folks have figured out how to peel and remove the small spines on the outer skin before consumption.  Cactus figs are also used to make candies, jelly and a form of drink called Bajtra; not that I’m advising it, as tiny, finely barbed hair-like spines can be ingested, causing distress to throat, lips, and tongue.

Mosquitoes I believe that it is safe to assume that no matter where you’re from, you know what a mosquito is.  According to the BC Center for Disease Control, here in BC we’ve been lucky to date as we experienced few cases of West Nile Virus (late 2010).  This isn’t to say that we won’t see more cases in the future, so it’s a good idea to protect yourself from these flying cretins.

We don’t see a lot of mosquitoes in most parts of the city, especially areas far from the channel parkway and lakes.  As soon as you leave the city limits and ascend the mountains however, it’s another story.  Many is the time that I’ve danced around slapping at my arms, shoulders and back, waiting for a friend to rest, change a flat tire or fix a broken chain.

One has three lines of defense against mosquitoes; many people choose to spray DEET on clothing and exposed skin.  All DEET-based repellents work by interfering with the mosquito’s ability to detect carbon dioxide and specific odors that they can sense.

It’s best to select a product based on how long you will be outside, a lower concentration of DEET (7-10%) will last about 90 minutes or so, depending on your level of physical activity (swimming / sweating etc.) while a 100% concentration of DEET may last about 12 hours.

The key is to use the lowest concentration based on your planned activity. For protection from ticks, use at least a 20% concentration product.  DEET and other repellent ingredients will sting the eyes, the stinging goes away immediately upon flushing your eyes with water however.

I’m not a big fan of DEET; preferring to take my chances with natural topical or spray products such as eucalyptus-oil based solutions.  Several studies have shown that they can be as effective as DEET, but that they don’t last as long, so more frequent applications are required.  I recommend that you also read the corporate line here.

Wear densely woven, long-sleeve clothing, and avoid outdoor recreation at dawn and dusk, as this is when the insects are more prevalent. Unfortunately, many people like to go out at those times as mid-summer in the Okanagan tends to be uncomfortably hot during the balance of the day.

More information on mosquitoes, DEET and other insect-borne diseases can be found on the BC Center for Disease Control

Reference studies are available in truncated form on PubMed

Field evaluation of three plant-based insect repellents against malaria vectors in Vaca Diez Province, the Bolivian Amazon.  Moore SJ, Lenglet A, Hill N. London School of Hygiene and Tropical Medicine, United Kingdom

Evaluation of a eucalyptus-based repellent against Anopheles spp. in Tanzania. Trigg JK. Department of Medical Parasitology, London School of Hygiene and Tropical Medicine, United Kingdom

Comparative efficacy of insect repellents against mosquito bites. Fradin MS, Day JF