Poison Hemlock (Conium maculatum) is everywhere – post for Earth-friendly Chroniclers’ #10

Poison Hemlock flowers 1It is easy mistake the poison hemlock plant (Conium maculatum) with another plant called “Queen Anne’s lace” (Daucus carota – and also called wild carrot).

Poison hemlock and Queen Anne’s lace belong to the same family of plants (carrots and parsley).  So, not only are the delicate, pretty white flowers similar, the leaves are similar too!

Over the years, I’ve enjoyed seeing the beautiful white flowers of these plants in different parts of California.  I spent a lot of time on the road in my prior work — and a lot of time stuck in traffic in the Bay Area — which means, a lot of time to look out the window and see plants growing on the side the road.

I thought these flowers all came from the same plant (Queen Anne’s lace) and did not know very much about them.

Through the Earth-Friendly Chroniclers’ Challenge this month — focused on biodiversity — I now know that there are two different plants with very similar flowers that grow here in my ecoregion.

Blue Sky and trees

Challenge, #10 asked that we play a naturalist version of I “Spy!” at our ecoregion, to take a camera, and observe what we see.  I went to the greenbelt space behind where we live here in the Central Coast.

I “spied” these familiar flowers and wanted to know more, because there were many of the plants here.  Most were already flowering, with white, lacy blooms.  There were rather tall plants (taller than me) and some of the flowers came from shorter plants.

Unlike the yellow starthistle or iceplants (posted for Challenge #9), which are listed as a high priority invasive plant, the Calflora website listed the poison hemlock (Conium maculatum) as a “moderate” problem.

Poison Hemlock in CaliforniaWhile it is good to know that this plant is not (at least not yet) as problematic as the iceplant or starthistle in California, it was disturbing to learn that these plants have naturalized here and are now invasive.

Even more disturbing is to learn that all parts of these plants are toxic (flowers, seeds, leaves, canes)…and even the dead parts of the plants can remain toxic for up to 3 years.

Poison Hemlock flower details

And not mildly toxic, or an irritant, but really TOXIC, as in the plant is deadly for humans and animals.

Poison hemlock is native to Europe’s Mediterranean region.  The ancient Greeks used the plant to poison prisoners condemned to death — including the philosopher Socrates.

The Death of Socrates by Jacques-Louis David 1787

The Death of Socrates by Jacques-Louis David

Because these plants are in the same family of plants as carrots and parsley, it is understandable how people can accidentally ingest the plants.  From a May, 2015 Food Safety News article:

All parts of poison-hemlock can kill humans and animals, even when it is dried. Foragers can easily mistake it for wild carrot (Queen Anne’s Lace), parsley, parsnip, sweet cicely, anise, fennel, wild chervil, and caraway, as well as other plants in the parsley or carrot family (Apiaceae), such as the violently toxic western-water-hemlock, or watercress, which is in another family.

…“Misidentifying poison hemlock or other toxic plants can have truly tragic results,” says Alison Halpern, executive secretary of the Washington State Noxious Weed Control Board. “Learn from an expert before foraging for wild plants, and if you think you have poison hemlock on your property, contact your county weed board, conservation district, or WSU Extension office to learn how to safely get rid of it.”

While poison hemlock is considered invasive, the Quee Anne’s lace plant, though not native to California (and a plant that has also naturalized in the wild), is not considered invasive.

Queen Annes Lace CalfloraWhich means…the plants that I’ve observed growing by the side of the road and in other places in California for all these years, were likely poison hemlock and not Queen Anne’s lace.

In other parts of the U.S., it may be easier to differentiate the two based on bloom periods, but in California, the flowering periods are similar:  Poison hemlocks bloom from April to September, while the Queen Anne’s lace flowers from May to September.

Poison Hemlock Plants

Poison hemlock plants can grow up to 8 feet tall.

Last summer, my grandsons and I spent time a lot of time walking around this greenbelt area (where there are also invasive Himalayan blackberries — and poison oak).

They know to stay away from poison oaks…and I’m glad they did not try to pick any of these flowers.

Poison Hemlock flowers 6

Unless you are absolutely sure which plant is which, it is best to treat these lovely flowers as poisonous, and to be careful of handling them.

I don’t have photos of the Queen’s Anne lace plant yet, but you can view a good collection at this USDA plant database page.

Poison Hemlock flowers

If you want to learn more about how to remove this toxic plant from your area, please contact your local agency, e.g., for Monterey County, start with the Agricultural Commissioner’s office, or see this USDA State Resource page.

The King County (Washington State) website has a section on noxious weed control. Excerpt and link below…

Removing poison hemlockWhen digging or mowing large amounts of poison-hemlock, it is best to wear gloves and a mask or take frequent breaks to avoid becoming ill.  One individual had a severe reaction after pulling plants on a hot day because the toxins were absorbed into her skin…(click here for more).

Poison Hemlock Plants 2Since writing this post, I’ve noticed these plants in spots (by the roadside mostly) here in Monterey County, and I’m surprised that it is not listed on Monterey County’s weed threats.

Do poison hemlocks grow where you live?

Did you get the flower and plant confused with the Queen Anne’s lace flowers, as I did?

Yellow Starthistle: Invasive plants and the Earth-Friendly Chroniclers’ Challenge

Sometimes, it is hard to know what plants are native to the area.  If you see it everywhere, for as long as you can remember, it must be native, right?

Field of Yellow Starthistles

Field of yellow starthistle – Photo via Invasive.org (Creative Commons) by Joseph M. DiTomaso, University of California – Davis, Bugwood.org – See more at: http://www.invasive.org/browse/detail.cfm?imgnum=5374358#sthash.rDPc2dA5.dpuf

Or maybe the weather and the soil is perfect for the type of plant, and actually it is an invasive plant — a “plant bully”, the theme for this week’s Earth-Friendly Chroniclers’ Challenge hosted by JustAnotherNatureEnthusiast.org.

Yellow Starthistle Detail

Photo – Creative Commons by Stephen Ausmus, USDA Agricultural Research Service, Bugwood.org – See more at: http://www.invasive.org

When we lived in the East Bay area (Contra Costa County, California), yellow starthistles grew by the side of the road, in between paved walkways, in open fields…and in our backyard.

The spines under its bright yellow flowers were notorious for its strength and sharpness, and often flattened my daughter’s bike tires.

These thistles were brought to North America  by accident in the 1800’s, and now grow in just about every state in our nation, and in Canada.

It is considered an invasive species in California, and as you can see from the first photo for this post, absolutely thrives in many parts of California.

From the California Invasive Plant Council:

Yellow starthistle is native to southern Europe and western Eurasia and was first collected in Oakland, California, in 1869. It was most likely introduced after 1848 as a contaminant of alfalfa seed. Introductions prior to 1899 were most likely from Chile, while introductions from 1899 to 1927 appear to be from Turkestan, Argentina, Italy, France, and Spain (Gerlach in prep., Hillman and Henry 1928).

By 1917 it had become a serious weed in the Sacramento Valley and was spreading rapidly along roads, trails, streams, ditches, overflow lands, and railroad rights-of-way (Newman 1917). In 1919 Willis Jepson observed its distribution near Vacaville and stated: “It is 1,000 times as common as ten years ago, perhaps even six years ago” (Jepson 1919).

Yellow starthistles grow and thrive all over Contra Costa County, and in particular in the Black Diamond Mine areas (part of the East Bay Regional Park District), where these photos of our dogs Jake and Sara were taken in spring and early summer.

Jakey Boy

Jake — our black lab mix and best pound dog ever!

Sara Sassafras

Sara — the smallest, and sweetest Newfoundland…

During hikes in the summer and fall, we had to check our dogs during and after in case thistle spikes lodged near their paws, or attached to their fur.

Jake and Sara Contra Costa County hike

Our dogs Jake and Sara — ahead of us in scenery typical of Eastern Contra Costa County, California. By summer, many fields (like this one) will be blanketed with yellow starthistle flowers…establishing itself in wider and wider areas…

By summer, you could see the yellow starthistle’s flowers across many of the fields and hiking trails.  It crowds out native plants…and because of its long tap root, uses water that would otherwise be used by native grasses and native plants species.

It took me several years to completely get rid of it in our backyard.  I don’t like using herbicides (or pesticides) so I manually pulled each one I found.  Because of its long tap roots, I had to get at the base of the plant (with gloves because the rest of the plant also had sharp and itch-producing properties) and do a sort of twist and pull motion to get at it, and then dispose of it in the garbage.

Garden area

After pulling out yellow starthistles from the backyard, we eventually had a decent garden and patio area. Photo of the garden area by the side of the house is of my daughter (in the middle) her friend, Jennifer at right, and our dog, Sara to the left.

With diligence, it is possible to get rid of yellow starthistles in an enclosed area, and once our garden plants and pavers were in place, I did not see anymore of it.

It’s another story in many parts of the Western United States.  Again, from the From the California Invasive Plant Council:

Yellow starthistle had spread to over a million acres of California by the late 1950s and nearly two million acres by 1965. In 1985 it was estimated to cover eight million acres in California (Maddox and Mayfield 1985) and perhaps ten to twelve million acres a decade later. It is equally problematic around Medford in southwestern Oregon and in Hells Canyon in Oregon and Idaho (Maddox et al. 1985). It also infests, to a lesser degree, areas in eastern Oregon, eastern Washington, and Idaho (Roch and Roch 1988).

Aside from small-scale manual removal, other methods to control this invasive species are listed on the California Invasive Plant Council, including mechanical methods (mowing down the plants before the flowers produce seed in the summertime).

The USDA has also approved and continues to experiment with insects that attack the plant’s flowers to minimize seed production.

Horse

Photo of horse taken at a ranch in Placer County, near the Sacramento Metropolitan area.

I’ve seen articles that indicated the yellow starthistle is poisonous to horses, but grazing by sheep, goats or cattle before seeds are formed can be an effective way to control growth if done at the right time (May and June).

Do you have an invasive plant in your area — or backyard and want to join in the WordPress challenge?  Click here for details about this challenge, and visit links for the challenge guideline.

My next post will be about another invasive plant where we now live in the Central Coast of California  —- the “ice plant”, which are seen along the coast and in the backyards of homes here in Monterey County.