This article was last updated by on

Cow Parsnip Vs Water Hemlock [Top Identification Keys]

Have you heard about the recent Water Hemlock vs. Cow Parsnip debate venting within the foraging community?

Although both plants are alike, only one is edible and meticulous attention can distinguish these poisonous herbs.

Cow Parsnip and Water Hemlock are morphologically identical with hollow stems, flower colors, habit, and leaf arrangement. However, the darker green foliage with much finer lobes of the Hemlock leaves distinguish it from the Cow Parsnip, with other contrasts in flower size, leaf texture, and toxicity.

Continue with the article to clear up other confusing buzzes regarding Cow Parsnip vs. Water Hemlock before putting your life in danger!

Cow Parsnip Vs. Water Hemlock: Similarities

Often people mistake the Cow Parsnip for Water Hemlock and other similar perennial weeds like Giant Hogweed and Poison Hemlock.

Both Cow Parsnip and Water Hemlock have similar umbel inflorescence with small white flowers blooming in clusters.

Additionally, both of these plants grow nearby waterbodies. Hence, they have similar, if not the same, growth habits and flowering seasons (between May to June).  

Further, the serrated feathery compound leaves and hollow stems make the Cow Parsnip and Water Hemlock appear the same.
Image represents difference between Cow Parsnip & Water Hemlock
Cow Parsnip and Water Hemlock are fast-spreading weeds.

Also, Cow Parsnip vs. Hemlock debate is prospering as both plants belong to the Apiaceae family with other poisonous members like Wild Carrots.

Cow Parsnip Vs. Water Hemlock: Differences

Cow Parsnip grows bigger and blooms 1-2 months earlier than Water Hemlock.

Firstly, take the leaf size, as the Cow Parsnip leaves are 6-24 inches long while the Water Hemlock leaves are 3-6 inches in length.

Additionally, the Water Hemlock leaves are elliptical to lance-shaped with slighter leaflets.

Contrarily, the Cow Parsnip leaves are obovate to orbicular in shape with broad leaflets. 

Similarly, Cow Parsnip stems are green, with purplish-lavender patches and soft hairs. In contrast, Water Hemlock stems have purplish/ lavender-pink blotches on a green backdrop with a smooth surface.
Image illustrates the difference between Cow Parsnip and Water Hemlock
Cow Parsnip and Water Hemlock have a few differences in their leaves, stems, and roots.

Moreover, Cow Parsnip has thick, coarse, and tapering tap roots, much more similar to the roots of Wild Parsnip.

But the roots of Water Hemlock are comparatively smoother, curved, and clustered.

Further common differences between the Cow Parsnip and Water Hemlock are highlighted in the table below.

FeaturesCow ParsnipWater Hemlock
Leaf ColorDark green with matte finishLight green with glossy shine
Plant Height4-10 feet3-6 feet
Blooming TimeApril to JuneMay to September
Flower Number15-30 rays in the umbel flowers10 or more rays in the umbel flowers
Flower Cluster Spread12 inches across in diameter6 inches across in diameter
FragranceA mix of Parsley and AniseedNo smell at all
ToxicityLow to mild toxicity

The sap can cause irritation and rashes to the skin.
High toxicity

All parts of the plant is highly toxic to pets, livestock and humans.

You might want to examine the similarities and differences between the Cow Parsnip and Poison Hemlock. One is more fatal than the other, but they look so similar! 

From Editorial Team

More on uses & toxicity!

Cow Parsnip can soothe colds and sore throats,  but it has a strong flavor, and some cannot tolerate it.

Though Water Hemlock is a medication for migraine headaches and painful menstruation, cicutoxin can severely cause poisonous effects in livestock and humans.