Griggs Reservoir Park

Columbus, OH


Griggs Reservoir is a park located in Franklin County, in northwest Columbus, alongside the Scioto River as shown in Figure 1. This park features nearly 190 land and 360 water acres, consisting of both biking and hiking trails, a full disc golf course, nature preserves, as well as boating docks. Running alongside the Scioto, one of the main features is the Griggs Dam, which is central to the park at 40.0624° N, 83.1052° W. The dam is named after chief engineer, Julian Griggs, for his years of dedication and work in the city of Columbus. Last summer, I traveled to Griggs Reservoir Park and was blown away by the incredible scenery, which is why I chose to return for my botanical survey. In Figure 1, the dam is marked with a yellow star.

Figure 1: A map of Griggs Reservoir Park and surrounding locations.

Poison Ivy

Toxicodendron radicans

Poison ivy found at Griggs Reservoir Park in Columbus, OH.

This survey required some intense botany skills, especially when it comes to the safety of the botanist themself. One of these skills is the ability to identify (AND AVOID) the dreaded poison ivy. Poison ivy is easily identifiable if you put in the work to understand its unique structure/appearance. This toxic plant has pinnately trifoliate leaves, meaning the leaflets are grouped in threes with the vertically growing leaf of the group being divided from the other two by an extension of the stem, called a rachis. Poison ivy is green, like any other plant, so one must be able to use their knowledge of this structure, AND information about the leaves themselves to be able to avoid it. The leaves are mostly entire and simple but have a few broad serrations along the edges of the leaf itself. The oil produced by poison ivy is called urushiol and causes dermatitis when in contact with human skin. Animals are resistant to poison ivy and use it as shelter, and sometimes food!

Flowers and Inflorescences

Philadeplphia Fleabane

Erigeron philadelphihcus

Philadelphia fleabane found at Griggs Reservoir Park in Columbus, OH.

This pretty wildflower is known as the philadelphia fleabane and is a member of the Asteraceae, or daisy, family. The flowers of this plant have white petals with yellow centers (gynoecium/androecium), and are radially symmetrical. Its leaves (near the base) are smooth and rounded, with the slightest lobes. As you move up the stem, the leaves become slightly serrated and more pointy at the tip. The carpels are fused in a syncarpous manner, and the gynoecium is inferior, meaning this flower is epigynous. The philadelphia fleabane has a composite inflorescence type, meaning it has both disk and ray flowers. This wildflower is typically found in areas of partial shade to full sun, with moist soil and not many surrounding plants. This particular plant was found off the side of a moist/shaded trail at Griggs Reservoir Park. The philadelphia fleabane also produces fruit, which is a dry seed that is small in size and is characterized by light brown hairs that are attached to the seed’s body. According to the United State Department of Agriculture (, this wildflower was formerly used in an eye medicine to help with poor vision!

Common Ninebark

Physocarpus opulifolius

Common ninebark found at Griggs Reservoir Park in Columbus, OH.

This gorgeous shrub is known as common ninebark and is a member of the Rosaceae, or rose, family. This shrub’s leaves are dark green, glossy, and alternately arranged on the stem. They resemble maple leaves with their three serrate lobes and pointed tips that are more commonly found near the base of the shrub. Ninebark produces flowers that have five white petals, five sepals, and one carpel per unit (unicarpellate). This species is unique for its extended sepals with bright red anthers! The flowers have radial symmetry and seem to be umbels, but are actually racemes, and are hypogynous. They produce fruits that are follicles and have a reddish-brown appearance. Ninebark is typically found in areas of decent moisture and partial shade to full sunlight. According to Medicinal Herbs (, ninebark’s bark was used, many years ago, to make a tea that could help treat tuberculosis.

Yellow Woodsorrel

Oxalis dillenii

Slender yellow woodsorrel found at Griggs Reservoir Park in Columbus, OH.

This tiny yellow flower is called slender yellow woodsorrel and is a member of the Oxalidaceae, or wood sorrel, family. Its leaves are unique and look somewhat like a pinwheel, with their palmately compound structure, heart shape, and soft green coloration. The flowers resemble those in the buttercup family, but are not to be mistaken! This plant has five bright yellow petals, a syncarpous and hypogynous gynecium with a superior ovary and radial symmetry. This plant’s inflorescence is considered to be a cyme. The fruit produced by yellow woodsorrel are capsules that grow at the terminal shoot of the plant, and are actually edible, along with the plant’s leaves (they taste lemony)! According to Specialty Produce (, the yellow wood sorrel is also called “sour grass” because of its taste and is used as a topical to heal dermatitis.

Great Waterleaf

Hydrophyllum appendiculatum

Great waterleaf found at Griggs Reservoir Park in Columbus, OH.

TThe great waterleaf is a gorgeous plant with light purple flowers, and it belongs to the Boraginaceae, or forget-me-not, family. This species features leaves with maple-like lobes with a few broad serrations along the edges. The leaves are alternately arranged and are simple in complexity, with bright green coloration. The flowers of this plant have five petals, five sepals, a superior gynecium (hypogynous) that is syncarpous, as well as radial symmetry. The great waterleaf is native to the eastern United States and prefers to reside in forests with moist soil and calcareous substrate. This particular one was found going up the incline between Griggs Dam and the parking lot, in an area of partial shade. According to Edible Wild Food (, this plant was once used as an oral salve to treat dry lips and mouth sores!

Invasive Species

Dame’s Rocket

Hesperis matronalis

Dame’s rocket found at Grigg’s Reservoir Park in Columbus, OH.

Dame’s rocket is a member of the invasive species list in Ohio. It is native to the Mediterranean and central Asia and was introduced to the United States, as an ornamental plant for landscaping, in the 1600s. Dame’s rocket grows in many conditions, so it has a large and widespread effect on many ecosystems. It grows rapidly and prevents other plants from growing and developing, by blocking sunlight and stealing nutrients. To prevent this, herbicides specific to broadleaf plants are being used to kill off some of them, according to Iowa DNR (

Multiflora Rose

Rosa multiflora

Multiflora rose found at Grigg’s Reservoir Park in Columbus, OH.

Multiflora Rose is another member of Ohio’s invasive species list. Native to Eastern Asia, this plant made its way to the United States in 1866 as an ornamental flower. Like Dame’s rocket, multiflora rose also reproduces rapidly. It produces fruits called hips which are frequently eaten and dispersed by birds, spreading the species all over. This plant is very thick and not only prevents native species from growing but also prevents animals from taking shelter. To combat multiflora rose’s impact, glyphosate and triclopyr are chemicals that are used to kill the plants, typically in the early summer before flowering according to the United States Department of Agriculture (

Amur Honeysuckle

Lonicera maackii

Amur Honeysuckle found at Grigg’s Reservoir Park in Columbus, OH.

This plant is another on the invasive list in Ohio. Amur honeysuckle is native to eastern Asia and came to the United States in 1896 as an ornamental flower to be used for erosion control and wildlife habitats. This invasive species inhabits areas of partial shade and moist soil, preventing surrounding native species from growing and reproducing. According to the United State Department of Agriculture (, the most effective way to control this species is to pull seedlings/sprouts when they first appear.

Japanese Stiltgrass

Microstegium vimineum

Japanese stiltgrass found at Grigg’s Reservoir in Columbus, OH.

Japanese stiltgrass is native to eastern Asia, especially Japan and Korea. It came to the United States in 1919 when transported as packing material for porcelain, according to NYIS ( This grass has decreased biodiversity within ecosystems and is known to crowd out other species. To avoid this, chemicals known as glyphosate and glufosinate are used as spot treatments to kill the plant, and sprouts are being pulled from the soil.

Woody Plant Fruit Identification

American Sycamore

Platanus occidentalis

American Sycamore found at Grigg’s Reservoir Park in Columbus, OH.

This little green sphere is the fruit of an American Sycamore. It is unique in that it has a green center with brown outgrowths (older parts of the fruit). This fruit is called an achene, and it is a dry sphere that carries seeds for reproduction. These fruits are found dangling from the stalks of sycamore trees!

Black Walnut

Juglans nigra

Black walnuts found at Grigg’s Reservoir Park in Columbus, OH.

These wrinkly, dark brown fruits seem to be nuts, but they are not! They are actually drupes, which are fruits known as “stony fruit” because of their hard pit, which is the seed. These fruits are unique because of their texture and size (as you can see in the image above), and are easily identifiable as black walnut.

Common Burdock

Arctium minus

Common burdock found at Grigg’s Reservoir in Columbus, OH.

At first, I was quite confused when I saw this fruit. I wasn’t quite sure how to identify it, but after doing some digging, I recognized the bristles as those of common burdock. The fruits are achenes and are light brown in coloration, with darker brown speckles. The fruits above are dried out and will soon fall off.

Indian Strawberry

Potentilla indica

Indian strawberry found at Grigg’s Reservoir Park in Columbus, OH.

The indian strawberry is incredibly easy to identify, because of its fruit type and bright red coloration. The fruit is known as an aggregate of achenes, meaning the body holds many small achenes out the outside (seeds). The outside of the fleshy part is dark red and the inside is much lighter, and even somewhat pink.

Mosses and Lichens

Lemon Lichen

Candelaria concolor

Lemon lichen found at Grigg’s Reservoir Park in Columbus, OH.

Baby Tooth Moss

Plagiomnium cuspidatum

Baby tooth moss found at Grigg’s Reservoir Park in Columbus, OH.

Plitts Rock Shield Lichen

Xanthoparmelia plittii

Plitt’s rock shield lichen found at Grigg’s Reservoir Park in Columbus, OH.

Anomodon Moss

Anomodon attenuatus

Anomodon moss found at Grigg’s Reservoir Park in Columbus, OH.