You can find two types of hogweed in America and Canada – common hogweed and giant hogweed. Both types of hogweed (Heracleum) are a part of the parsley family. You can see the resemblance between this plant and parsley in the shape and color of the leaves and flowers.
Hogweed is identified by its thick, purple-spotted, and bright white hairy stems. The leaves are broad, non-uniform, and heavily incised. The flowers grow in clusters called umbels and are white (giant hogweed) or pink (common hogweed).
Many plants resemble hogweed, which is why other species are often mistaken for this weed. These plants include:
- Poison hemlock – the flowers and stems resemble that of hogweed
- Cow parsnip – all parts of the plant look like hogweed; the differences are faint
- Queen Anne’s lace – the flowers look identical to hogweed
- Wild parsnip – the same stalks and flower structure has hogweed
- Water hemlock – the coloring of the stems and flowers resemble hogweed
- Valerian – stems, and flowers look like hogweed
- Elderberry – same hollow stems, and the flowers look like hogweed
- Wild lettuce – the stems look like hogweed
If you’re interested in knowing how these plants resemble hogweed and how you can tell them apart, take a look at the following list.
1. Poison Hemlock (Conium maculatum)
When looking at a poison hemlock plant, one can see many similarities between it and giant hogweed. Poison hemlock is about the same size as hogweed and grows between 4 and 9 feet tall. The stems also look similar since they have the same shade of green stems with purple spots.
However, where hogweeds stems have prominent white hairs that cover the stems, the stems on a poison hemlock plant are smooth. Though the flower bunches of poison hemlock also resemble those of hogweed, they are slightly smaller. They don’t grow as densely packed together as hogweed umbels.
Like hogweed, poison hemlock is also toxic. It can be deadly to humans, even after the plant has died.
2. Cow Parsnip (Heracleum maximum)
Cow parsnip is one of the plants that gets confused with hogweed the most often. This is because these two plants look remarkably similar, and one can only tell them apart upon closer inspection. The leaves are the same color and have the same incised shape as hogweed leaves, though they are more uniform.
The stems are also covered in white hairs, but the hairs aren’t as prominent or hard as those on hogweed stems. The stems are usually green, with slight purple coloring – different from the purple marks on hogweed.
The flower bunches look the same as hogweed, but the umbels are smaller, and the flowers appear earlier in the season. Cow parsnip can cause the same skin irritations as hogweed, so it’s best to leave the plant alone.
If you touch cow parsnip, wash the area immediately and protect it from the sun for at least 48 hours. Cow parsnip can cause burns when exposed to sunlight that scar and take months to heal.
3. Queen Anne’s Lace (Daucus carota)
Queen Anne’s lace might appear similar to hogweed in some ways, but other characteristics set them apart. The similarities between Queen Anne’s lace and hogweed primarily reside in the flower color and structure. Queen Anne’s lace also produces small, white flowers that grow in bunches.
But the flowers and the bunches are much smaller than hogweed. The entire plant also grows about 4 feet tall, half the size of hogweed. The stems are covered in white hair but are much thinner than hogweed. The leaves also don’t look like hogweed leaves, as they are much smaller and fern-like.
Despite having similarities with hogweed, the roots of Queen Anne’s lace are edible. However, all parts of the plant are toxic to animals.
4. Wild Parsnip (Pastinaca sativa)
Wild parsnip also resembles hogweed at a distance, but the similarities start and end with the flower shape. Wild parsnips produce small, yellow flowers that grow in umbels. The plant grows about 5 feet tall, making it smaller than hogweed. The stems are a darker green, grooved, and smooth.
Wild parsnips have compound leaves with a stem and leaflets. The leaflets have similar incisions as hogweed leaves, but the leaf structure differs significantly. It’s not as easy to mistake wild parsnip for hogweed when the plant is not blooming.
Wild parsnip, like cow parsnip, causes the same irritations as hogweed. The plant is less toxic than giant hogweed but like common hogweed. Try not to touch it if possible to avoid the chemical burns this plant can cause.
5. Water Hemlock (Cicuta maculate)
When strolling by a river or pond, you may notice flowers that look similar to hogweed and may assume that it is. But these flowers most likely grow on a water hemlock plant – known to grow near water sources. Water hemlock plants grow 3 to 6 feet tall. They have smooth stems with many branches.
The stems are green or purple, which also resembles hogweed. Water hemlock plants produce small, white flowers that grow in umbels, but the umbels are slightly smaller than hogweed ones. The leaves are also easy to distinguish from hogweed since they are much smaller and sharp-edged.
Water hemlock is also toxic. This includes all parts of the plant. Water hemlock is among the most toxic plants in America and is fatal to humans and animals, which is why you should give it a wide berth.
6. Valerian (Valeriana officinalis)
Valerian is another plant that looks similar to hogweed when you see it from afar. The plant structure is similar, growing about 5 feet tall and slightly smaller than hogweed. The white or pink flowers remind one of hogweed, but they don’t grow in umbels like hogweed flowers.
They bloom around the same time, making it easier to mistake one for the other. Valerian plants also have green stems, sometimes with red or purple streaks, but they don’t have the purple markings or white hairs of hogweed stems.
Unlike hogweed, valerian isn’t considered a toxic plant. But it also isn’t entirely edible, and some side effects can occur from ingesting it. Fortunately, you won’t have chemical burns after touching valerian as you will after touching hogweed.
7. Elderberry (Sambucus nigra ssp canadensis)
Elderberry is another plant sometimes mistaken for hogweed. The elderberry flowers resemble those of giant hogweed as they grow in large bunches. An elderberry plant can grow bigger than a hogweed, sometimes reaching up to twelve feet.
But the leaves and stems of elderberries differ significantly from the hogweed. The leaves are smaller, darker, and more pointed. The stems are smooth and have a silvery grey color. Elderberries are also non-toxic plants.
They can make people nauseous and aren’t eaten too often. Unlike hogweed, elderberries won’t cause skin irritations or burns when handling the plants.
Related: Are Elderberries Poisonous?
8. Wild Lettuce (Lactuca Visora)
Wild lettuce may also look like hogweed when the plant is not in bloom. The biggest resemblance between wild lettuce and hogweed is the purple-stained stems. But where hogweed stems are hairy, wild lettuce stems are smooth.
Wild lettuce leaves are much smaller and thinner than hogweed leaves, and they alternate on the sides of the stem. The flowers have the same size as hogweed flowers but look more like dandelions.
Like the hogweed plant, wild lettuce also causes skin irritation. The sap within the plant can cause burns when exposed to the sun, which can take several months to fully heal and may lead to scarring. Best to leave this plant alone if you encounter it.