Poison Ivy – Live and Let Live


I haven’t thought about poison ivy (Toxicodendron radicans) in a very long time. When a friend sent two photos of it for ID confirmation last week, it became a highlight of my week. As we discussed this plant, the initial response was to get rid of it. Yet it’s native and wildlife depend on native plants. How many depend on this “unpopular” plant? I had to know.

As humans, we immediately want to eradicate anything that might cause us harm. Rather than learn to live with it and understand its value, our reaction is to kill it and remove it.

What if…we left it?

Electing to live in harmony with poison ivy means my small piece of the earth could gain from the diversity and benefits of this native plant and I could keep myself safe. Solid identification skills, a grasp of what makes it hazardous, and a list of wildlife using the plant makes living with poison ivy safe and enjoyable.

Poison Ivy Has Leaves of Three, But…

Poison ivy can be tricky to identify. While the “leaves of three” mantra is what I grew up learning as a way to identify the plant, it was confusing as there are many plants with 3 leaves. Adding to the complexity of this plant is its color changes —  “reddish in the spring; green in the summer; and yellow, orange or red in the fall” (Wilson, nd). And compounding that, poison ivy can be found as a hairy-looking vine climbing a tree, a small shrub, or a mass collection of short plants. However you might encounter it, all parts (roots, stem, leaves) can cause a skin rash.

The oily substance in poison ivy is “…urushiol (oo-roo-shee-ohl). Its name comes from the Japanese word “urushi,” meaning lacquer”(Wilson, nd). When urushiol makes contact with the skin, the body sends the white blood cells to fight this foreign substance. As the body’s immune system neutralizes this foreign agent some normal tissue gets damaged in the process. This damage is what we see on our skin as a rash.

 

Wildlife Uses Poison Ivy

Studying the biota as we restore our land’s native ecosystems caused me look at these “plants that could hurt me” differently. Each native plant is a host to insects, meaning they require this plant to sustain the next generation. These insects, in turn, are the protein birds, reptiles, amphibians, and small mammals require to raise their young. Berries and seeds are adult food; the babies require protein and that means insects. Aha! I began to look at all native plants with new eyes.

A little research uncovered 153 invertebrates, 48 birds, and 7 mammals that depend on or use this plant in some way to sustain life. While not an exhaustive list, it is an impressive list.

Coleoptera (Beetles)

Altica chalybea (Habeck 1988)
Analeptura lineola (Senchina, 2005, Senchina and Summerville 2007)
Apsectus hispidus (Habeck 1988, Senchina 2005)
Astyleiopus variegatus  (Habeck 1988)
Astylidius parvus (Steyskal 1951, Habeck 1988, Senchina 2005)
Astylopus macula (Senchina 2005)
Bassareus brunnipes (Habeck 1988)
Calligrapha floridana (Habeck 1988)
Chalcodermus aeneus (Habeck 1988)
Chauliognathus marginatus (Senchina, 2005)
Chauliognathus pennsylvanicus (Senchina, 2005, Senchina and Summerville 2007)
Cryptorhynchus fuscatus (Habeck 1988, Senchina 2005)
Ctenicera hamatus (Habeck 1988, Senchina 2005)
Derocrepis erythropus (Habeck 1988)
Diplotaxis bidentata (Habeck 1988, Senchina 2005)
Enoclerus rosmarus (Senchina, 2005, Senchina and Summerville 2007)
Euderces picipes – Senchina and Summerville 2007
Eugnamptus collaris (Habeck 1988)
Eupogonius  vestitus (Senchina 2005)
Eusphyrus walshi (Steyskal 1951, Senchina 2005)
Hypothenemus toxicodendri  (Habeck 1988, Senchina 2005)
Leiopus variegatus (Senchina 2005)
Leptostylus albescens (Habeck 1988, Senchina 2005)
Lepturges querci (Habeck 1988, Senchina 2005)
Lepturges signatus (Steyskal 1951, Habeck 1988, Senchina 2005)
Madarellus undulatus  (Habeck 1988, Senchina 2005)
Molorchus sp. – Senchina and Summerville 2007
Oberea ocellata (Senchina 2005)
Orthaltica copalina  (Steyskal 1951, (Habeck 1988, Senchina 2005)
Pachnaeus opalis  (Habeck 1988)
Pachybrachys tridens  (Steyskal 1951, (Habeck 1988, Senchina 2005)
Phyllophaga uklei (Habeck 1988, Senchina 2005)
Pityophthorous consimilis (Senchina 2005)
Pityophthorous rhois (Senchina 2005)
Pityophthorus corruptus (Habeck 1988)
Pityophthorus crinalis (Habeck 1988)
Pityophthorus tutulus (Habeck 1988)
Saperda lateralis (Habeck 1988, Senchina 2005)
Saperda puncticollis (Steyskal 1951, Habeck 1988, Senchina 2005)
Serica vespertina (Habeck 1988, Senchina 2005)
Strangalia acuminata (Senchina, 2005, Senchina and Summerville 2007)
Synchroa punctata  (Steyskal 1951, (Habeck 1988, Senchina 2005)
Thanasimus  dubius (Senchina 2005)
Trischidias atoma (Habeck 1988)
Xyleborus affinis (Habeck 1988, Senchina 2005)
Xyleborus ferrugineus (Habeck 1988)
Xyleborus pecanis (Senchina 2005)

Lepidoptera (Moths and butterflies)

Acronicta impleta (Habeck 1988)
Acronicta longa (Habeck 1988)
Amorbia humerosana (Habeck 1988)
Anavitrinelia pampinaria  (Habeck 1988)
Antepione thisoaria (Habeck 1988)
Archips argyrospila (Habeck 1988)
Caloptilia diversilobiella (Habeck 1988)
Caloptilia ovatiella (Habeck 1988)
Caloptilia rhoifoliella (Habeck 1988)
Cameraria guttifinitella (Habeck 1988)
Celastrina neglecta  (Senchina, 2008b, Senchina and Summerville 2007)
Choristoneura rosaceana (Habeck 1988)
Cingilia  cantenaria  (Habeck 1988)
Dichorda iridaria (Habeck 1988)
Ecpantheria scribonia (Habeck 1988)
Epipaschia superatalis (Habeck 1988)
Epipaschia zeleri (Habeck 1988)
Episimus argutanus (Habeck 1988)
Eutelia furcata (Habeck 1988)
Eutrapela clemataria (Habeck 1988)
Hyphantria cunea (Habeck 1988)
Lambdina fiscellaria somniaria (Habeck 1988)
Lophocampa maculata (Habeck 1988)
Lymantria dispar (Habeck 1988)
Marathyssa basalis (Habeck 1988)
Nystalea eutalanta (Habeck 1988)
Orgyia leucostigma (Habeck 1988)
Oxydia vesulia transponens (Habeck 1988)
Paectes oculatrix (Habeck 1988)
Platynota rostrana (Habeck 1988)
Prolimacodes badia (Habeck 1988)
Sibine stimulea (Habeck 1988)
Sparganothis reticulatana (Habeck 1988)
Stigmella rhoifoliella (Habeck 1988, Steyskal 1951)
Thyridopteryx ephemeraeformis (Habeck 1988)
Xanthotype sp.  (Habeck 1988)

Hymenoptera (Bees, wasps, sawflies)

Agapostemon viriscens (Senchina and Summerville 2007)
Andrena spp (Senchina and Summerville 2007)
Andrena crataegi (Illinois wildflowers website)
Apis mellifera (Senchina and Summerville 2007)
Arge humeralis (Habeck 1988)
Augochlora pura (Senchina and Summerville 2007)
Bombus fervidus (Senchina and Summerville 2007)
Cimbex  americana (Habeck 1988)
Eumenes fraternus (Senchina and Summerville 2007)
Lasioglossum spp. (Senchina and Summerville 2007)
Osmia lignaria (Senchina and Summerville 2007)
Sceliphron caementarium (Senchina and Summerville 2007)
Vespula sp. (Senchina and Summerville 2007)
Xylocopa sp.  (Senchina and Summerville 2007)

Diptera (Flies)

Anthrax analis  (Senchina and Summerville 2007)
Dasineura rhois (Habeck 1988)
Laphria sp. (Senchina and Summerville 2007)
Lasioptera sp. (Habeck 1988)

Hemiptera

Alconeura sp. (Habeck 1988)
Aulacorthum rhusifoliae (Habeck 1988)
Carolinaia caricis (Habeck 1988)
Carolinaia carolinensis (Habeck 1988)
Carolinaia rhois (Habeck 1988)
Clastoptera obtusa (Habeck 1988)
Coelidia sp (Habeck 1988)
Cyrpoptus belfragei (Habeck 1988)
Duplaspidiotus claviger (Habeck 1988)
Ferrisia virgata (Habeck 1988)
Glabromyzus schlingere (Habeck 1988)
Graphocephala versuta  (Habeck 1988)
Heterothrips vitis (Habeck 1988)
Lygaeus kalmii  (Senchina and Summerville 2007)
Metcalfa pruinosa (Habeck 1988)
Nezara viridula (Habeck 1988)
Orthezia insignis (Habeck 1988)
Osbornellus rotundus  (Habeck 1988)
Penthemiafloridensis (Habeck 1988)
Phenacoccus pettiti (Habeck 1988)
Pseudaonidia duplex (Habeck 1988)
Pseudococcus longisetosus (Habeck 1988)
Pulvinaria acericola (Habeck 1988)
Pulvinaria floccifera (Habeck 1988)
Pulvinaria rhois (Habeck 1988)
Pulvinaria urbicola (Habeck 1988)
Rugosana querci  (Habeck 1988)
Saissetia oleae (Habeck 1988)
Selenothrips rubrocinctus (Habeck 1988)

Acari (Mites)

Aculops rhois  (BugGuide website)
Aculops toxicophagus (Habeck 1988)
Eriophyes rhois (Habeck 1988)

Birds

Bluebird (Martin et al 1951)
Bobwhite (Martin et al 1951)
Bush-tit (Martin et al 1951)
Catbird (Martin et al 1951)
Cedar waxwing (Martin et al 1951)
Chickadee, Black-capped (Martin et al 1951)
Chickadee, Carolina (Martin et al 1951)
Chickadee, chesnut-backed (Martin et al 1951)
Chickadee, Mountain (Martin et al 1951)
Crow (Martin et al 1951)
Finch, Purple (Martin et al 1951)
Flicker, red-shafted (Martin et al 1951)
Flicker, Yellow-shafted (Habeck 1989, Martin et al 1951)
Grouse (Martin et al 1951)
Junco (Martin et al 1951)
Kinglet, Ruby-crowned (Martin et al 1951)
Magpie, American (Martin et al 1951)
Magpie, Yellow-billed (Martin et al 1951)
Mockingbird (Martin et al 1951)
Pheasant (Martin et al 1951)
Phoebe (Martin et al 1951)
Quail (Martin et al 1951)
Sapsucker, Red-breasted (Martin et al 1951)
Sapsucker, Yellow-bellied (Illinois wildflower website)
Sparrow, Fox (Martin et al 1951)
Sparrow, Golden-crowned (Martin et al 1951)
Sparrow, White-crowned (Martin et al 1951)
Sparrow, White-throated (Martin et al 1951)
Starling (Illinois wildflower website)
Thrasher, Brown (Martin et al 1951)
Thrasher, California (Martin et al 1951)
Thrush, Hermit (Martin et al 1951)
Thrush, Russet-backed (Martin et al 1951)
Thrush, Varied (Martin et al 1951)
Titmouse, Tufted (Martin et al 1951)
Towhee, Spotted (Martin et al 1951)
Turkey, Wild (Martin et al 1951)
Vireo, Warbling (Martin et al 1951)
Vireo, White-eyed (Martin et al 1951)
Warbler, Cape May (Martin et al 1951)
Warbler, Myrtle (Martin et al 1951)
Woodpecker, Downy (Martin et al 1951)
Woodpecker, Hairy (Martin et al 1951)
Woodpecker, pileated (Martin et al 1951)
Woodpecker, Red-bellied (Martin et al 1951)
Woodpecker, Red-cockaded (Martin et al 1951)
Wren, Cactus (Martin et al 1951)
Wren, Carolina (Martin et al 1951)
Wren-tits (Habeck 1989)

Mammals

Black bear (Martin et al 1951)
Cottontail rabbit (Illinois wildflower website)
Deer, mule (Martin et al 1951)
Deer, White-tailed (Illinois wildflower website)
Muskrat (Martin et al 1951)
Pocket mice (Habeck 1989, Martin et al 1951)
Wood rat (Martin et al 1951)

Resources:

BugGuide website, https://bugguide.net/node/view/15740, Accessed 10 May 2020

Ewing, H.E., 2015. “Mites affecting the poison ivy.” The Proceedings of the Iowa Academy of Science, Volume 24

Habeck, Dale H. 1988. Insects associated with poison ivy and their potential as biological control agents. Proceedings VII International Symposium, Rome Italy

Illinois Wildflower website. https://www.illinoiswildflowers.info/trees/plants/poison_ivy.htm. Accessed 13 May 2020.

Martin, Alexander C., Herbert S. Zim, and Arnold L. Nelson. 1951. American Wildlife and Plants: A Guide to Wildlife Food Habits. New York: Dover Publications, Inc.

Senchina, David S. 2005. Beetle interactions with poison ivy and poison oak. The Coleopterists Bulletin, 59(2): 328-334.

Senchina, David S. and Keith S. Summerville. 2007. Great diversity of insect floral associates may partially explain ecological success of poison ivy. The Great Lake Entomologist 40(3, 4)

Steyskal, George. 1951. Insects feeding on plants of the Toxicodendron section of the genus Rhus. The Coleopterists Society 5(5/6): 75-77.

Wilson, Stephanie. How Poison Ivy Works. https://science.howstuffworks.com/life/botany/poison-ivy.htm. Accessed 13 May 2020





How to ID Sedges

Sedges often remain a mystery for many of us.  Sedges are mainly found in moist soil in full sun although there are also many species that enjoy woodlands and dry bluffs. You’ll find them in flower mostly during the months of April, May, and June. Sedges are differentiated from grasses by a number of characteristics, but the simplest one is the stem. A sedge stem is triangular and solid; a grass stem is round and hollow. There are some sedges that are annuals but all the of the Carex species are perennial. Whether you can ID the sedge or not, the good news is that you are very unlikely to encounter a non-native sedge species. 

John Larson and Nate Gingerich

John Larson and Nate Gingerich led a field trip and offered the following tips.

Equipment you’ll need with you:

  • A 10x loupe
  • A good field guide or two
  • Know the terminology and structural parts of a sedge. This takes times but it makes working through the dichotomous keys much easier!
  • Have a good metric ruler. Many of the IDs are dependent upon an accurate measurement. A millimeter or two can change the ultimate identification.
  • Take a plastic bag. This will keep whatever you collect fresh. When you do take specimens from the field, be sure to take 2 or 3 leaves and seed heads from the same plant.
  • Know the habitat. It helps to know where to look for sedges and also when you collect a portion to ID, make a note of the habitat. Sedges are mainly in moist soil but there are some that grow in woods and on dry, rocky bluffs. Knowing where the sedge is found can narrow down the ID. 

7 key elements that need attention

1. Basal leaf sheath

What color is it? Green or brown/purple? Basal leaf sheaths are described as purple/brown and green. This is often better determined in the field than on a specimen removed from the field.

Sedge ID

2. Back side of the leaf sheath

Look for distinctive veining; does the leaf sheath has interesting or unique lines?

sedge ID

3. Spike shape and configuration

Particularly determine how male and female flowers are arranged- are they on separate spikelets or are they combined in the same spikelets, and if combined which are on top and which are below? Scales, bracts, and leaves can be easily mistaken. Beaks can be in different shapes.

Sedge ID

4. Stigma numbers and shape

Stigmas can be curled in a couple of shapes and can have more than one.

Sedg ID

5. Summit of the leaf sheath

Look at the shape and texture of the top of front side of leaf sheath.  Is it firm, flimsy, clear, green, spotted, etc?  Does it end in a concave, convex, or straight line?

Terminal and lateral spike, leaf sheath, peduncle

Plant growth

Is it clumping or not?

Carex blanda

7. Habitat and location

It helps to know what county or part of a state the sedge is found

Additional Resources

  • Field Guide to Wisconsin Sedges by Andrew Hipp
  • Spring Flora of Wisconsin by Norman Fassett
  • Sedges: Carex by Robert Mohlenbrock
  • Sedges: Cyperus to Scleria by Robert Mohlenbrock
  • Woodland Carex of the Upper Midwest by Linda Curtis