Marah oregana

Marah oregana has been in the local news recently, so I thought I’d feature it. Its 6cm-long cucumber-like fruit correctly suggests it is in the same family as cucumbers, squashes and watermelons. Tendrils, another characteristic pointing to Cucurbitaceae (though not exclusively so), can be seen in these photographs of Marah oregana from 2003.

Like all Marah species, Marah oregana is western North American in distribution; the species ranges from southwest British Columbia to northern California. The small population in British Columbia represents the northernmost extent of the genus, while other species push the range of the genus south into northwestern Mexico and east into New Mexico. One member of the genus was previously featured on BPotD: Marah fabacea. That entry contains a link (“whopping one”) to the reason for the common name of manroot for the genus, but here’s another photograph of a Marah tuber if you don’t want to dig for it. Marah oregana is commonly called coast(al) manroot, and given the size of the tubers, I suspect individuals have the largest underground biomass of any individual non-woody plants in British Columbia (but I’m happy to be corrected) and perhaps even Canada.

Eighteen individuals are known to exist in the wild in Canada. The reason the species has been in the news is because a decision was made to not list the species as endangered under Canada’s Species At Risk Act. For the story, see: Coast manroot fails to catch Kent’s eye: Environment minister rejects committee’s suggestions for endangered species list. The noted committee is COSEWIC, the Committee on the Status of Endangered Wildlife in Canada, “a committee of experts that assesses and designates which wildlife species are in some danger of disappearing from Canada”. In November 2009, COSEWIC assessed Marah oregana as endangered (see the Marah oregana Assessment and Status Report (PDF)). On July 4, 2012, the decision behind the Order not to add the species to SARA was posted.

As an aside, many references use Marah oreganus for the name instead of Marah oregana; USDA GRIN taxonomists and the 2nd Edition of The Jepson Manual have switched the gender to the feminine, in accordance to the classical gender of the Hebrew name Marah.

Marah oregana

10 responses to “Marah oregana”

  1. Katherine

    Are the huge roots edible (for animals) at all? These plants are very common in our area (sandy cliff areas surrounding California’s Monterey Bay) and gophers are also extremely common (unfortunately). I wonder if the plants suffer any damage from gophers chewing the tubers.
    Oh, and until I saw the previous BPotD posting on this, I had never heard of a manroot. We call this a wild sea cucumber. Once I saw the photo of the tuber, I abandoned my attempts to pull up this “weed”.

  2. Daniel Mosquin

    No, I don’t think any part of the plant is edible. See use by humans of Marah via Wikipedia. My understanding is that Marah is named after the bitter waters of Marah that could not be imbibed.

  3. Ruth

    Peter Kent is not my kind of people! Manroots are awesome!

  4. Eric Simpson

    Here in north coastal San Diego County, we have Marah macrocarpus, which I grew up knowing as Indian squash. Didn’t know about the massive tubers; I always assumed they grew from seed anew each year.

  5. elizabeth a airhart

    also known as old man in the ground
    are the spines used by the manroot to keep animal life
    away from the fruit or small ladders for the little folk
    thank you all

  6. Katherine

    Thanks for your answer, Daniel!
    That explains why they flourish in such gopher-ridden territory.

  7. Ted Kipping

    Daniel, the name Marah means “bitter” and if you have ever tasted ANY portion of this plant, you will appreciate its aptness. Some of the California aboriginals used the seeds in a game similar to marbles & shooters. The seeds are just the right size for Jays to cart off and cache. Jack Sigg at Strybing Arboretum in S.F. dug up a volunteer Marah in the Arboretum and stashed the massive tube behind a shed. It continued to produce 40 foot vines and flowers and fruits for years without aid of any irrigation. I am guessing that the hugh tuber development is a very successful adaptation to a rapidly drying climate.

  8. Meighan

    I had no idea this plant grew here, fascinating. Is it fruiting now? I’ll have to look for it on my next visit to the garden.

  9. Daniel Mosquin

    Yes, fruiting now. I went back to see the plants 3 days after I took this photograph, and noticed a few fruits had already burst open and were starting to drop seeds. I collected these as we are going to try and establish a plant in the Garry oak area, since it is associated with Garry oak plant communities in BC. Incidentally, I think this species also has the largest seed of any native species in British Columbia.

  10. Meighan

    I came this morning to see it – but I was way too late, the fruits were all open and dried out. I’ll be sure to look for it next year. The native garden was full of wildlife today – I found a frog, a downy woodpecker, several humming birds, sticklebacks, chickadees, etc.

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