The Associated Press

Poison hemlock is a health risk to anyone who comes in contact with it, officials warn. (Associated Press photo) | ZOOM |

COLUMBUS - Don't pick those pretty clusters of small, white flowers you see growing along highways.

They're actually a weed called poison hemlock, and state wildlife and poison control officials warn that handling them can make you sick.

Poison hemlock is a European weed brought to North America more than a century ago as an ornamental plant.

"Poison hemlock has become one of the most prevalent weeds in Ohio, especially along highways in Columbus, Dayton and Cincinnati," said Joe Boggs, a horticulture specialist with the Ohio State University Extension South District.

"It was a bit of a landscape oddity a few years ago, but now you don't have to look hard to find it."

It is found in unkempt yards and fields, and along railroad tracks, irrigation ditches, stream banks and waste areas.

The flowers bloom between June and August during the second year of growth. Birds and rodents carry the fast-growing plant's seeds. It's a health risk for anyone who comes in contact with it, Boggs said.

Known as the plant that did in Greek philosopher Socrates, the weed can grow as tall as 10 feet. Its leaves are often mistaken for parsley, its roots for parsnips and its seeds for anise, Boggs said.

Because it is pretty, it often is brought indoors and displayed.

Sometimes, children chew on it, and that's trouble.

Symptoms can include seizure, vomiting and respiratory failure, said Dr. Marcel Casavant, medical director of the Central Ohio Poison Control Center.

Casavant said the center has received several calls about poison hemlock in recent years.

Jan Scaglione, director of pharmacy at the Cincinnati Drug and Poison Information Center, said the weed is so plentiful in Hamilton County that the center put out an alert last year.