Pretty Poison Hemlock

Ladybug on a hemlock flower

How to tell plants from very far away:
#1 the Hemlock

Most people around here know and respect poison oak, a native plant whose leaves and stems contain a potent oil that can cause your skin to erupt into an itchy blistering rash if you brush up against it. But few are aware that we have a more toxic poison plant common to this area.  This one can kill you if you eat at least 5 or 6 leaves. It is an invasive species, not native to Bay Area. In fact, it comes from the Mediterranean and was used as a method of execution several thousand years ago.  It is Poison Hemlock (Conium maculatum), the plant that killed Socrates about 2400 years ago.

Lots of people think that hemlock is a tree, and there is a conifer called the hemlock, but that's not where the famous (or infamous?) poison comes from.  Instead it comes from this plant in the carrot family.  Poison hemlock has lacy, almost fern-like leaves just like a carrot's, but it grows up to 8 feet tall.  It really does look like a giant carrot plant.  I would not recommend eating the root, though, as it is poisonous, too.

According to literature online, the poison works by paralyzing the muscles that keep you breathing, so you basically suffocate.  The antidote is to get in an iron lung or respirator or something that will artificially keep you breathing until the effects wear off in a few days.

Hemlock Leaf

These specimens were growing in Wildcat Canyon Regional Park, but they are in bloom in most open space parks around the Bay Area.