Plants

This page contains brief notes for plant identification and removal of invasive species. Natives are listed first; scroll down for invasive species. Some maintenance notes at the very bottom. For more information (lots more, with pictures) try the illinois wildflowers website, especially the woodland plants section.

Native Species

You can look for these (and impress your friends by calling them out!) along both sides of the Trail. Often they’ll show up in clusters of several of the same plant in the same section of trail and then little or none in another section. Many may have been planted at the same time during the naturalization of the riverbank. Some might have been damaged during restorative controlled burning of individual trail sections, but most native Illinois prairie and savanna plants are adapted to periodic fire and will be healthy and thriving by mid-summer.

Sedges – “sedges have edges” These taller clumps of grass-like plants are often identified by their triangular stems.

Columbine – mid-sized (2-4 feet tall) wildflower, reddish dangling flowers in Spring and Summer

Golden Alexander – lighter version of delicate parsnip, leaves from stem.

Goldenrods – there are many native species of goldenrod with small showy yellow flowers. The species that are primarily found along the Trail are tall goldenrod and canada goldenrod. Along both are native they can be aggressive and shouldn’t be allowed to overrun other natives, about 2 feet tall, in large areas at various places along the trail, the easiest spot to find will be a big patch of it (perhaps 10 feet wide) on the west side near the north end of the trail.

Wild Geraniums – low, 6-12 inches, with purple flowers in the Spring

Solomon’s Seal – a single central stem, that would be 2-3 feet tall, except that it leans over to one side, with bigger leaves (4-6 inches long), and whitish green or pale yellowish flowers that hang down from the stems in clusters of three, late Spring and early Summer.

Shooting Star – 6-12 inches, small white to pink flowers that ‘shoot’ off a central stem.

May Apples – a low-lying flower with bigger leaves and white flowers that hang below the leaves, in Spring. this one spreads underground, through rhizomes (horizontal stems that send out roots).

Dogwoods – a shrub to small tree 4-10 feet tall, with opposite silky leaves with arching veins you can break open and see little strands of whitish of “latex” stretching out between the pieces.

Viburnums – bushy shrubs with small white flowers in Spring, 4-5 feet tall in many places, could use some pruning by somebody with those special skills and experience.

Early Meadow Rue – three leaves together and little greenish flowers

False Sunflower – some of these just north of the zig-zag section of the trail.

Joe Pye Weed – tall stalk with leaves 2-4 feet, with flat mass/domed cluster of flowers, smells like vanilla when crushed, with white powdery “glaucus” visible at stem joints.

Virginia Water Leaf – low, 1-3 feet tall, little fuzzy white flowers

Milk Weed – opposite leaves, pink flowers, seed pods in the fall, and milky sap that can cause a skin rash

Orchard Grass – non-native, but also fairly non-aggressive

Elderberry – opposite, compound 5-7 leaves, white dots when young, with warts on bark. berries are red. can be harvested and fermented. yum.

Ash – trees with opposite leaves, each with five to seven leaflets. These can be seen growing along the water’s edge.

River Birch – two or three of these trees, with peeling bark and small, fluttering leaves, at the south trailhead

Cottonwoods – native river tree, a cousin of Trembling Aspen.

Invasive Species

These are species that would overrun everything else if we let them. Most are non-native plants brought to North America either intentionally or unintentionally. Once free of their natural pests and environmental stressors these plants have the ability to spread rapidly. We pull and cut and dig this stuff as we’re able, trying to hold it back a bit and give the natives a better chance of taking hold. We’ll never eliminate the non-natives as their seeds will continue to be carried into the Trail area by the wind, birds and animals, but we can keep these plants in check. Note that different plants need to be removed in different ways to be most effective.

Wild Parsnip – a hearty plant with sprays of yellow flowers, three and four feet tall. of special note, the resin of this plant will cause minor but irritating burns, in sunlight. At a trail day last year, Pete Leki suggested it as a natural and temporary tattooing compound… if you like pink tattoos. removal of this requires gloves and herbicide, usually done by park contractor.

Garlic Mustard – sprays of tiny white flowers in the Spring, about 18 inches tall, not too much of this so far, but look for it along the east side at the very start at the North end. tear the leaves of this and smell it — then you’ll know why they call it garlic mustard! seed pods later in summer look like little “sticks”. REMOVAL is easy, just pull it up gently, but collect it and make sure it gets hauled out in the trash, because the pulled plants will still go to seed and those seeds will grow next year, a big new bunch of garlic mustard all around where you left the piles.

Burdock – big wide leaves growing on stalks that spring in all directions from a single spot on the ground, up to three feet tall. this plant has a big root that has various medicinal uses, but all soil in the city should be tested before eating produce, especially roots veggies (carrots, radishes, and… burdock) are taken internally. REMOVAL requires digging out the root as deeply as possible. The long tap root can be severed with a garden shovel below the ground. This may need to be done several years in a row in order to kill the plant.

Thistles – these are the tall prickly plants that grow as single leafy stalk with a large pink to purple flower. There are nice native thistles in Illinois, but the ones we find along the Trail are invasive introduced from Eurasia, like Canada Thistle (which is called Canada Thistle because it was first identified in Canada but is actually native to Eurasia) REMOVE by digging or pulling out the root.

Box-Elder (tree saplings) – compound leaves in threes, seed pods that hang down in the spring, might be 2 to 4 to 6 or more feet tall, with white powdery looking stems. Native trees that are prolific seeders and can quickly overrun a small area like the Ronan Nature Trail if left unchecked. REMOVE these and other saplings by cutting off at the ground and applying herbicide to the (hopefully small) stumps.

Buckthorn (tree saplings) – perhaps the most notorious invasive tree in the area, originally brought in and planted by farmers across the midwest as dividers and windscreens for their fields. look for it’s shiny leaves and dark bark. REMOVE these saplings by cutting at the ground and applying herbicide to the stumps.

White Mullein – tall stalk with fuzzy leaves, will make decent TP in a jam.

Nightshades – red berries, small purple summer flowers

Sumac – red-tinged leaves, looks similar to Tree of Heaven.

White Mulberry – can be aggressive, varied leaves, some look like mittens, big dark berries. leave large plants, remove smallest saplings.

Sweet Clover – remove by pulling.

Bind Weed – a tangling, strangling vine that needs to be pulled out at the roots.

Cup Plant – a large plant with leaves that form a “cup” around the stem. this plant is an aggressive native that occasionally needs control.

Some Notes on Maintenance

Herbaceous Weed Removal – garlic mustard in best pulled in the spring while it is flowering and before it sets seed (late April – late May) and should be removed from the site so that seeds don’t drop and germinate. Other invasives such as sweet clover and burdock can be pulled throughout the summer.

Controlled Burning – ONLY performed by licensed contractor at Chicago Park District sites! Happens in Spring or Fall.

Cutting Tree Saplings – best done in late fall/early winter when herbicide will be drawn down into root.

Seeding – best done in fall

Planting – best done in Spring, into May/June