Poisonous hemlock

Poisonous hemlock popping up in Saanich

Invasive plant poisonous hemlock can grow two metres

Saanich’s flora is flourishing in the summer sun, but Royal B.C. Museum experts are warning about a particularly dangerous and poisonous plant showing up more frequently across the Capital Region.

Poisonous hemlock, or Conium maculatum, is an invasive species that can kill if ingested by causing respiratory arrest.

(SEE A RELATED SAANICH NEWS STORY ON INVASIVE, POISNOUS HOGWEED)

Hemlock is just coming into full bloom, said Ken Marr, Royal B.C. Museum curator of botany.

“It’s important to get (this plant) in people’s awareness,” Marr said.

Poisonous hemlock is infamous for being the plant which Socrates was forced to ingest in Ancient Greece in order to take his own life, having been found guilty of poisoning young minds by spreading his philosophy, said Rachelle McElroy, executive director of the Coastal Invasive Species committee.

“Poisonous hemlock is one we’re seeing more of, just because of the transfer of soil between different municipalities or regions,” McElroy said.

“It outcompetes our native vegetation and it has prolific seed production, which continues over winter. It’s in the same family as giant hogweed, with that same toxin,” she said.

When buying soil, customers may want to ask if nurseries can guarantee they have invasive-free soil, McElroy suggested.

It’s also important to pull the entire root when removing poisonous hemlock, and always wear protective gloves and clothing when dealing with the plant.

Poisonous hemlock looks somewhat similar to parsley, though it can grow nearly two metres in height.

Marr cited a 2002 case when two people cooked and ate some of the plant, possibly mistaking it for another member of the parsley family.

The couple reported numbness in their mouths, followed by respiratory arrest and ended up spending five days in hospital.

Marr said the fact they cooked the plant before eating it likely saved their lives.

If ingested, the plant can cause paralysis, which can lead to an inability to breathe and, ultimately, death.

Poisonous hemlock is identifiable by the purple splotches found on its stem, a distinguishing characteristic in the parsley family.

It is also related to giant hogweed, another poisonous plant commonly found in Greater Victoria.

“Don’t eat anything in that family unless it’s in your garden,” Marr said.

The plant is also poisonous to livestock, so local farmers should be on the lookout as well, Marr added.

“Do not compost this plant,” McElroy said. “The best thing is to place all parts in a garbage bag, use gloves, wash all clothing and tools afterwards, label it invasive species and take it to the Hartland landfill,” she said.

Royal BC Museum curators have samples of poisonous hemlock dating back to 1914, and Marr said he is available to identify plants for the public if they bring in samples or send a photograph. Contact him at kmarr@royalbcmuseum.bc.ca.

“We have training and specialized knowledge from being in the field and seeing the plants,” Marr said. “We have a lot of expertise here that’s available to the public.”

Any landowners who find poisonous hemlock on their property are advised to contact the Coastal Invasive Species Committee to report and identity the plant, either by phone at 250-857-2472 or by email at info@coastalisc.com.

editor@saanichnews.com