Spotted water hemlock, a native North Dakota plant, has been reported in most North Dakota counties. The plant is highly poisonous to humans and all livestock, especially cows, horses and goats. The plant's toxin, cicutoxin, is most harmful in the spring. The roots are the most toxic, but all parts of the plant can be poisonous.
Spotted water hemlock is a short-lived perennial plant that spreads by seeds and roots, and thrives in moist to wet soils, allowing floodwater and birds to help spread seeds. It is most often found in wet and subirrigated meadows and along the edge of cattail sloughs and low-lying roadside ditches, water drains and creek bottoms. However, it can occasionally be found in better-drained soils near these wet areas.
“Most cases of concern are when spotted water hemlock ends up in hay bales,” says Joe Ikley, NDSU Extension weed specialist. “Awareness and prevention are key. Avoid baling any plants you can’t confidently identify.”
With the much drier weather this year and the need to cut more acres of hay, NDSU Extension cropping systems specialist Jeff Stachler advises farmers and ranchers to scout wet areas for the presence of spotted water hemlock before cutting for hay.
A member of the carrot family, spotted water hemlock can be difficult to identify. It is often confused with water parsnip, a non-toxic native plant. Both grow in similar, moist-to-wet environments and can reach 2 to 6 feet tall. Most other carrot family species live in more well-drained soils.
Some distinguishing characteristics between spotted water hemlock and water parsnip include:
- Stem: Spotted water hemlock has smooth, reddish to purple streaked/vertical-veined hollow stems with chambered roots. Water parsnip has green, somewhat angled stems with little to no hair, and a nearly square stem at the base of the compound umbel.
- Leaves: Spotted water hemlock leaves have one to three subdivided leaflets with a more deeply toothed leaflet margin. Water parsnip leaves have paired single leaflets with short, sharp margins and are not subdivided like spotted water hemlock.
- Flowers: Spotted water hemlock has compound umbel flower heads in more of a dome shape, about 4-6 inches across, while water parsnip has compound umbel flower heads that are flatter and smaller, about 2–5 inches across.
“The plant’s sap may cause skin irritation in some people,” says Ikley. “Use caution and wear gloves when investigating unknown plants.”
Source : ndsu.edu