Iowa's Plants Series - Iowa's Shrubs and Vines

Iowa's Shrubsand Vines

Iowa Association of Naturalists

Iowa's Plants

1Iowa's Shrubs and Vines

Editorial BoardText: Dan CohenIllustrations: Mark MüllerLayout and Design: MJC Associates, Ankeny, IowaPublished by: Iowa Association of Naturalists

The Iowa Association of Naturalists (IAN) is a nonprofitorganization of people interested in promoting the development ofskills and education within the art of interpreting the natural andcultural environment. IAN was founded in 1978 and may be contactedby writing the Conservation Education Center, RR 1, Box 53, GuthrieCenter, IA 50115.

Iowa Association of Naturalists

Iowa's Plants Booklet Series

Plants are a beautiful and important part of nature in Iowa. To assist educators inteaching their students about the common plants of Iowa, the Iowa Association of Naturalistshas created a series of booklets which offer a basic, understandable overview of Iowa's plants,their ecology, and their benefits and dangers to people. The seven booklets in this seriesinclude:

Iowa's Spring Wildflowers (IAN-301)Iowa's Summer and Fall Wildflowers (IAN-302)Benefits and Dangers of Iowa Plants (IAN-303)Iowa's Trees (IAN-304)Seeds, Nuts, and Fruits of Iowa Plants (IAN-305)Iowa's Mushrooms and Nonflowering Plants (IAN-306)Iowa's Shrubs and Vines (IAN-307)

For ordering information about these and other IAN publications, please see the backcover of this booklet.

Resource EnhancementAnd Protection

Education Board

Review CommitteeCele Burnett, Environmental Education Coordinator, Story County Conservation Board

Dan Cohen, Naturalist, Buchanan County Conservation BoardJean Eells, Environmental Education Coordinator, Hamilton County Conservation Board

Judy Levings, State 4-H Youth Development Specialist, Iowa State UniversityStacey Snyder Newbrough, Freelance Naturalist and Librarian, Pocahontas, IA

Jim Pease, Extension Wildlife Specialist, Iowa State UniversityDiane Pixler, Naturalist, Marshall County Conservation Board

The Iowa Plants booklet series ispublished by the Iowa Association ofNaturalists with grants from the REAPConservation Education Board and theIowa Conservation Education Council(ICEC), 1994.

2 Iowa Association of Naturalists

Iowa's Shrubs

and Vines

Shrubsand Vines

Plants come in many forms. Trees are the tallestplants and usually have a single woody stem called atrunk. Smaller plants that have several woody stemsare called shrubs. Those plants that climb and twistalong the ground and on taller shrubs and trees arecalled vines. The showier forbs are the wildflowersand herbs that grow in woodland, wetland, andgrassland areas. Grasses usually have less con-spicuous flowers and tall, slender stems and leaves.Small nonflowering plants such as mosses, liver-worts, and algae often cover the rocks, logs, andground where there is more moisture.

Together, these groups of plants provide the basisfor natural communities. The shrubs and vines areespecially important in these communities as theyprovide food and shelter for a variety of wildlife.


Woodland plants are arranged in severalvertical layers, like the floors of a multi-level hotel.Beneath the woodland floor is the basement contain-ing tunnels and burrows that are home to a varietyof unique animals. The woodland floor may becovered by mosses, fungi, and low-growing wildflow-ers. The next level of the “forest hotel” may consist

of young trees and shrubs and vines. Smaller treesmake up the understory layer of the hotel. Thepenthouse suite is the high canopy which forms thegreen ceiling of the woodland. Each of these layerssupports a variety of wildlife, dependent on woodlandplants. Each spring, the woodland seems to come tolife one layer at a time as lower levels of the “hotel”become green and bloom before the higher levels leafout and block out sunlight.

The Forest Hotel

Canopy

Understory

Shrub and Vine Layer

Floor

Basement


Iowa’s shrubs and vines are most common inwoodlands, especially along woodland edges andopenings where they can receive sunlight. Shrubsare usually less than 15 feet tall, and vines can beseen at almost any height, trailing along the groundor climbing to the tops of the tallest trees. Some-

times the terms “shrub” and “vine” are con-fusing to people. Although blackberries and

other berry bushes are technically shrubs,people often say they are “picking ber-

ries from the vine.” And some vines,such as poison ivy, may creep along

the ground and form dense, shrub-like clumps. Because small treessuch as sumacs and chokecherrygrow in the vertical shrub forestlayer, they too are often referredto as shrubs, even though theyusually have a single woodystem. Shrubs are identifiable bytheir clonal pattern of growth,with several woody stemsspreading outward from a singlepoint.

The Shrub Layer

Small tree

Vine

Shrub


Each spring, before the woodland canopy be-comes leafy and blocks sunlight, shrubs and smalltrees become green and begin producing flowers.Gooseberry, honeysuckle, crabapples, and chokecherries produce their flowers early in spring. Bysummer, shrubs and “shrubby” trees are usuallyproducing an abundance of berries or other fruits.Some of these fruits, such as dogwood berries, maypersist late into autumn and provide an importantsource of food for wildlife. The foliage of shrubs suchas sumacs, gooseberries, and dogwoods are amongthe first to change color in autumn. They also pro-duce some of the most brilliant colors, making themeasy to identify at a distance.

Many Iowa woodlands contain a thick growth ofshrubs and vines. Shrubby woodlands are a re-minder that many of our woodlands were at one timepastured. Cattle choose not to bite into thorny

shrubs, allowing prickly plants to survive anddominate an area that has been grazed.Thorny shrubs and less tasty plants thatwere not eaten by cattle are common inIowa woodlands. Examples are shrubsand small trees such as gooseberries,honey locust, hawthorn, prickly ash,and multiflora rose. The shrub layer isless thick in well-developed and undis-turbed forests.

Gooseberry (Ribes missouriense)is a thorny shrub. The leaves areapproximately two inches long andhave rounded lobes that look some-what like a goose’s foot. The berriesare green, changing to purple as theyripen. The green berries are very sourbut become less sour as they turnpurple. Gooseberries provide thornycover for wildlife such as mice, rabbits,and songbirds and provide food forboth animals and people.

Iowa’s Shrubs andSmall Trees

Gooseberry

Thorny Thickets


Blackberry (Rubus allegheniensis) and blackraspberry (Rubus occidentalis) produce some of themost delicious fruits in Iowa woodlands. Both growas rambling thorny shrubs, but blackberry stemsare taller and more robust, sometimes growing to alength of ten feet. Blackberry leaflets are woollyunderneath, while black raspberries are not. Black-berry stems turn a maroon color as they age, butblack raspberry stems are somewhat whitish.Showy white blackberry flowers bloom in May andJune and produce the tasty aggregate fruits in Julyand August. Black raspberries begin blossoming asearly as April with fruits maturing in June and July.All native raspberries have characteristic compoundleaves with three to seven toothed leaflets andthorny branches.

Prickly ash (Xanthoxylum americanum) is ashrub or small tree that sometimes forms dense

thorny thickets. The compound leaves withtoothed egg-shaped leaflets are similar to thoseof ash trees. The “prickles” are found as pairsflanking the base of leaf stems and blossomsand along the leaf stalks. Prickly ash producessmall green, reddish brown, or orange berries.The shrub is usually less than ten feet tall and

is sometimes called “toothache tree” becausechewing the berries, leaves, or bark has a numbing

effect in the mouth. The berries produce a citrussmell and are not preferred by wildlife. Prickly ashflowers in April and May and produces berries fromJuly through September.

Hawthorns (Crataegus spp.) grow either as denseshrubs or small trees. There are many species ofhawthorns, but all have sharp thorns one to three

inches long that are without budsor leaves. They produce smallapplelike fruits that may beyellow or reddish in color. Al-though hawthorns are considereda “weed” in farm pastures, thornythickets provide important nest-ing habitat for birds along wood-land edges. The fruits, whichmay remain on the shrubsthrough the winter, are an impor-tant food for a variety of birdsand mammals.

Black Raspberry

Prickly Ash

Hawthorn


Not all woodland shrubs are thorny. Many, likethe various common species of dogwood, have softleaves and stems and produce fragrant flowers in thespring and berries during the summer. The shrublayer of an Iowa woodland is a wildlife grocery storeof berries and other fruits and seeds. Dogwoods,hazelnuts, honeysuckle, elderberry, and witch-hazelmay all be seen growing in Iowa woodlands andgrassland edges.

Red-osier dogwood (Cornus stolonifera) is amedium-sized shrub with bright red twigs. It growsto a height of less than 10 feet and is usually foundin wet areas along woodland edges. The two- to five-inch oval leaves have widely spaced veins and arewhitish on the underside. All dogwoods produceflowers and fruits that provide food for wildlife. Dog-wood twigs are eaten by deer and rabbits. Red-osierdogwood produces white berries from July throughOctober.

Hazelnut (Corylus americana) is a medium-sizedshrub with broad, rounded, doubly-toothed leaves.

The twigs and leaf stems have stiff hairs that give theshrub a rough feel. The nuts, sometimes calledfilberts, have a thin, raggedy edged, hairy husk. Awide variety of wildlife as well as people collect thetasty nuts during the late summer months. Hazel-

nuts are more common inthe eastern part of the state.

Other Common Shrubs

of Iowa Woodlands

Hazelnut

Red-osierDogwood


Elderberry (Sambucus canadensis) is a shrubthat usually grows to a height of four to eight feet.

The large compound leaves have many ovalleaflets. An identifying characteristic of elder-berry is the white pith that is obvious whenthe larger twigs are broken. Elderberryflowers and fruits grow as large flat-toppedclusters. The dark purple berries are oftenused to make jams, jellies, pies, and wines.Look for the berries during late summer andautumn.

Over time, Iowa prairies may be slowly trans-formed into woodlands. Without prairie managementor natural controls, shrubs and other woody plantsmay take over the grassland habitat. Shrubs andsmall trees are the first of the woody invaders togrow in a grassland. Plants such as wild rose,smooth sumac, dogwoods, and red cedar are amongthe first plants to enter the grasslands.

Shrubby Grassland Invaders

Elderberry


Wild rose (Rosa carolina) is the state flower ofIowa. It grows as a woody shrub in open woodlands,woodland edges, and prairies. The flowers are pink-

purple with yellow stamens and may be twoinches wide. They bloom from June throughSeptember. The leaves are oval, sharplytoothed, and divided into five to seven leaf-lets. Rose thorns are more conspicuous onlarger woodier stems. Rose fruits, calledhips, remain on the plant through winter andprovide a source of vitamin C.

Smooth sumac (Rhus glabra) is a small treeor shrub with smooth branches and large compoundleaves that turn brilliant purple in early autumn,making them easy to identify at a distance. Clumpsof red, hairy persistent fruits appear in autumn andprovide food for a variety of wildlife throughout falland winter. Poison ivy is in the same genus as thesumacs, and although smooth sumac is notpoisonous to the touch, poison sumac does containa dangerous skin irritant. Poison sumac, however,does not exist in Iowa.

Wild Rose

Smooth Sumac


Vines are plants that have adapted to life inshady woodlands by being able to climb up or creeptoward available sunlight. Most vines will crawl onthe ground or climb over rocks and living and deadplants. They may appear to be low-growing plants orbushes, or their leaves may be mistaken for theleaves of the tree they are climbing. Some vines,such as the non-native trumpet vine, produce showyflowers. Wild grape produces edible fruits. However,fruits from the other vines are not edible. The onlyvine in Iowa that is poisonous to the touch is poisonivy.

There is a definite advantage for plants that canreach through dense vegetation and find adequatesunlight. Without sunlight, green plants cannotphotosynthesize their food.

Trees and, to a lesser degree, shrubs are able toproduce stout woody stems that can support their

leaves at a greater height. These plantsexpend a lot of energy to create the

materials for this woody ladder.But vines have adapted to reach-ing high above other plantswithout having to create an“energy-expensive” woody stem.In order to climb to sunlight,vines use several devises.

Plants such as wild cu-cumber and wild grape havecoiled tendrils that naturally

Vines

Wild GrapeTendrils

Climbing to Sunlight


wrap around any object the plant encounters. Thetendrils are touch sensitive so that they grow moreslowly on the side that is in contact with an object.The other side continues to grow at the normal rateand eventually coils over the touched side. Tendrils

may be formed from modified branches, petioles,or leaflets.

In Virginia creeper, the tips of thetendrils have small adhering discs, called hold-fasts. The holdfasts act to hold the growingplant on its supporting structure.

Poison ivy and bittersweet climb with-out tendrils. To climb, they use twiningstems that grow in a spiral fashion that letsthem use other plants as a trellis. Poison ivysometimes sends out aerial roots as it climbs,but unlike tendrils, these roots do not coil.

Virginia CreeperHoldfasts

Poison IvyTwining Stems &

Aerial Roots


A few vines grow in woodlands throughout Iowa.Virginia creeper, wild grape, and poison ivy areespecially common. Other vines found throughoutIowa are bittersweet, wild cucumber, moonseed, andgreenbrier. Trumpet vine is native only to southeastIowa but has escaped from landscaped yards to livein the wild throughout the state. Vines growthroughout the woodland, adding layers of leaves,blossoms, and berries to all layers of the forest.

Virginia creeper (Parthenocissus quinquefolia) isa very common vine which can climb 40 feet or moreusing numerous tendrils and holdfasts. It is some-times called five-finger or five-leaf ivy because eachleaf is divided into five leaflets. The leaves are green

throughout the summer, but in early fallthey change to a beautiful red or purplecolor. Occasionally a couple of leafletsmay fall off, causing Virginia creeper tobe confused with another common vine

called poison ivy.

Poison ivy (Rhus radicans) is avine which may take the form of a small

plant, bush, vine, or small tree. Leaves aredivided into three leaflets and grow alternately

up the leaf stem. The plant is sometimes con-fused with young boxelder plants which also have

three leaflets but grow opposite along the stem.Poison ivy is a plant that should be avoided

but need not be feared. Most people are allergic tothe oil which is produced on the leaves and stems ofpoison ivy. The poison can cause rashes and blisters

Iowa’s Vines

Poison Ivy

VirginiaCreeper


which may be painful. The reaction usually does notoccur until at least 12 to 24 hours after contact withthe plant and can normally be avoided by washingwith warm water and strong soap. Poison ivy is nota danger to wildlife and is a source of food for birdswhich eat its berries. Poison oak is similar to poisonivy but does not grow in Iowa.

Wild grape (Vitis riparia) is a verycommon vine of Iowa woodlands. Grapevines sometimes climb to great heights,making use of many tendrils. The leavesgrow alternately on the stem, are toothed,and have several shallow lobes. Wild grapesare edible for both people and wildlife. Thefruits are small, dark, and sweet. Nearly100 different species of songbirds andmany other birds and mammals areknown to feed on grapes.

Bittersweet (Calastrusscandens) is a thick vine of Iowa wood-

lands. It grows as a twining stemand has no tendrils or aerial roots.

The four-inch leaves are oval witha pointed tip and grow alternately

along the vine. Bittersweetproduces small inconspicuousflowers but is best known forits bright reddish orangefruits which persist into lateautumn or winter. Thescarlet berries are oftencollected for ornamentsand decoration.

Bittersweet

Wild Grape


Wild cucumber (Echinocystis lobata) has aweak, usually green stem that climbs with the aid oftendrils. The leaves are rough and somewhat star-shaped with several pointed lobes. The characteris-tic fruit is a spiny egg-shaped capsule. Althoughcommonly called a “cucumber,” it is not related tocultivated cucumbers and is not edible. The vine isalso sometimes called “squirting cucumber” becausethe dry fruit dramatically breaks open and flings thefour large seeds into the air.

Moonseed (Menispermumcanadense) is a smooth vinewith broad shallow-lobed leavesthat climbs using green twiningstems. White flowers beginblooming in May and producefruits in September and Octo-ber. The fruits are black with a

whitish powder. Moonseedfruits are poisonous, and care

must be taken not to confusethem with wild grapes.

Greenbrier (Smilax rotundifolia) is a thorny vinethat climbs using tendrils. The tendrils are at thebase of the leaf stalks and remain after the leaves falloff. Leaves are rounded and somewhat heart-shaped, and the stem is woody and green. Greenbri-ers are low-growing vines that often resembleshrubs. They flower during May and June andproduce black fruits that may remain on the vinethrough winter.

WildCucumber

Moonseed

Greenbrier


Shrubs, Vines, andWildlife

Shrubs in woodlands, woodland edges, fencerows, and open areas are often the most importantplants for wildlife. Dense thickets, flowering shrubs,and a variety of berries, nuts, and other fruits makeshrubs, vines, and small trees important places forwinter cover, protection from predators, and sourcesof food throughout the year.


Shrubs and vines provide a variety of deliciousand long-lasting foods for wildlife. Some foods, suchas wild grape, blackberries, serviceberries, andcherries, are especially tasty to wildlife and arequickly eaten. Other foods such as hawthorn anddogwood berries, although not immediately favoredby wildlife, are long-lasting and provide an impor-

tant source of food into the winter months. During the spring and summer months,

berry-producing shrubs and small trees such asmulberry, chokecherry, serviceberry, plum trees,blackberry, and black raspberry provide food forsongbirds and other wildlife. Deer, quail, chip-munks, and squirrels also feed on berries and onnuts, leaves, and stems of other shrubs. Blossom-ing dogwoods, honeysuckle, blackberry, trumpetvine, and other shrubby plants provide nectar forhummingbirds, butterflies, moths, and bees.Thicket-forming shrubs such as black raspberry andhawthorns provide important nesting cover. Virginiacreeper, poison ivy, and especially grape vines alsoprovide good summer cover and foods for wildlife.

As autumn and winter approach, food and shelterbecome most important for wildlife. Plants such asdogwoods, wild plum, highbush cranberry, service-berry, red cedar, and Virginia creeper provide criticalwinter habitat. When the snow falls, bittersweet,sumac, hawthorn, and crabapple fruits persist onthe leafless plants. Winter birds and mammals feedon the fruits and find shelter in the dense growth ofshrubs and vines.

Chokecherry (Prunus virginiana) is a small treeor shrub with smooth gray bark. The simple leavesare sharply toothed and grow alternately on thestem. Chokecherries have attractive white flowersthat produce berries from July through October. Thesmall bitter purple berries are eaten by wildlife andare sometimes collected by people for jellies, jams,and pie filling. Smaller stems and bark are occasion-ally eaten by wildlife.

Serviceberry (Amelanchier laevis), also calledJuneberry, is a beautiful shrub or small tree withpinkish red blossoms. The oval leaves are two tothree inches long and toothed. Like other membersof the rose family, the fruits are applelike. Althoughpeople use the fruits for jams and pies, most fruitsare quickly eaten by a variety of birds and mammals.

Chokecherry

Serviceberry


Wild plum (Prunus americana) is closely re-lated to the cherry trees. Plum trees have

simple toothed leaves and gray speckledbark. Unlike the cherries, most plum treeshave thornlike structures. Fragrant white

flowers blossom in spring. The yellow andred fruits are one-half to one inch in diam-

eter and contain a single large seed. Likethe cherries, plum trees provide food andcover for a variety of wildlife.

Red mulberry (Morus rubra) is Iowa’s nativemulberry bush. It may grow as a shrub or tree,sometimes growing very tall. The leaves have varying

lobes and are toothed. Taller trees, which maygrow from 30 to 50 feet, have a reddish brown

trunk. It is a relatively uncommon tree.On the other hand, the non-native

white mulberry is widespread. It isdistinguished by the orange-

brown bark on young trees andbranches of large trees. Its fruitis rarely white. Mulberry fruitslook like elongated blackberriesand are a favorite food of manysongbirds. People also enjoy thetasty berries that usually arecollected in June and July. Theseeds are often spread by birdsafter passing through theirdigestive tracts.

Wild Plum

RedMulberrry


Summary

Shrubs and vines are an important part of Iowawoodlands and grassland edges. Shrubs and smalltrees make up a forest layer that is rich in food andprovides winter cover for wildlife. Unlike shrubs andtrees, vines do not have thick, rigid stems that cancarry them to sunlight. Instead, they use tendrils,holdfasts, and twining stems to help them climb or

crawl to sunlight. Shrubs, small trees, and sometypes of vines may appear “bushy,” and all are some-times grouped as “shrubs.” True shrubs have severalwoody stems and are usually less than 15 feet tall.

Although some types of shrubs and vines may bedangerous to eat, nearly all are safe to touch, if youdon’t mind a few thorns. The exception is poison ivywhich is found throughout the state. Poison sumacsare also poisonous to the touch but are not currentlyknown to exist in Iowa.


Many Iowa shrubs are thorny and remind us thatmuch of our state has, in recent times, been pas-tured. Thorny thickets make excellent protectivecover for many types of wildlife. Many shrubs pro-duce beautiful flowers or tasty fruits enjoyed by bothpeople and wildlife. The diversity of shrubs, vines,and small trees along woodland-grassland edgesmakes for a diversity of wildlife.

Useful Resources

“Forest and Shade Trees of Iowa,” P.J. Van Der Linden and D. R. Farrar, Iowa StateUniversity Press, 1993.

“The Illustrated Book of Trees,” William C. Grimm, Stackpole, 1983.

Iowa State University Extension publications, contact your county extension office.

“Our Northern Shrubs and How To Identify Them,” Harriet Keeler, 1969.

“Poisonous Plants of the Central United States,” H.A. Stephens, University Press KS,1980.

“Trees and Shrubs,” Peterson Field Guides, George A. Petrides, 1986.

“Wild Edible Fruits and Berries,” Marjorie Furlong and Virginia Pill, Naturegraph, 1974.


Notes

Iowa's Shrubs and Vines is one in a series of seven booklets that are part of the Iowa Plants Series. Thebooklets in the series include:

Iowa PlantsIowa's Spring Wildflowers (IAN-301)Iowa's Summer and Fall Wildflowers (IAN-302)Benefits and Dangers of Iowa Plants (IAN-303)Iowa's Trees (IAN-304)Seeds, Nuts, and Fruits of Iowa Plants (IAN-305)Iowa's Mushrooms and Other Nonflowering Plants (IAN-306)Iowa's Shrubs and Vines (IAN-307)

The Iowa Association of Naturalists also has produced five other booklet series that provide readerswith a clear, understandable overview of topics concerning the Iowa environment and conservation. Thebooklets included in each of the other five series are listed below.

Iowa Physical Environment SeriesIowa Weather (IAN-701)Iowa Geology and Fossils (IAN-702)Iowa Soils (IAN-703)

Iowa Wildlife SeriesIowa Mammals (IAN-601)Iowa Winter Birds (IAN-602)Iowa Nesting Birds (IAN-603)Iowa Reptiles and Amphibians (IAN-604)Iowa Fish (IAN-605)Iowa Insects and Other Invertebrates (IAN-606)

Iowa's Natural Resource HeritageChanging Land Use and Values (IAN-501)Famous Iowa Conservationists (IAN-502)Iowa's Environmental Laws (IAN-503)Conservation Careers in Iowa (IAN-504)

Iowa Wildlife and PeopleIowa Wildlife and Management (IAN-401)Keeping Iowa Wildlife Wild (IAN-402)Misconceptions About Iowa Wildlife (IAN-403)State Symbols of Iowa (IAN-404)Iowa Food Webs and Other Interrelationships (IAN-405)Natural Cycles in Iowa (IAN-406)Iowa Biodiversity (IAN-407)Adapting to Iowa (IAN-408)

Iowa's Biological CommunitiesIowa's Biological Communities (IAN-201)Iowa Woodlands (IAN-202)Iowa Prairies (IAN-203)Iowa Wetlands (IAN-204)Iowa Waterways (IAN-205)

Iowa Environmental IssuesIowa Habitat Loss and Disappearing Wildlife (IAN-101)Iowa Air Pollution (IAN-102)Iowa Water Pollution (IAN-103)Iowa Agricultural Practices and the Environment (IAN-104)People, Communities, and Their Iowa Environment (IAN-105)Energy In Iowa (IAN-106)Iowa Waste Management (IAN-107)

Booklets may be ordered through the Iowa StateUniversity Extension Service at acost of $1.00 per booklet. Whenordering, be sure to use the IANnumber to the right of each listedbooklet title. Please send writtenorders and payment to:

ISU Extension ServicePrinting and Publications BuildingIowa State UniversityAmes, IA 50011515-294-5247

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Iowa's Plants Series - Iowa's Shrubs and Vines