# Prostrate knotweed why is it bad?



## Cowboy_Ken (Sep 4, 2012)

So I've done a search on the forum for, â€œpolygonum aviculare" and I come up with results saying it is a no feed plant for tortoises. Does anyone know why it's not ok? Thanks.


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## Yvonne G (Sep 4, 2012)

So THAT'S what that's called. I've always called it wire weed. My back yard is just covered with it...and I HATE it. When it first started showing up last summer, I was on my hands and knees pulling it. This year its so dense that you can't see the grass at all. It looks like a lawn of knotweed.

This is what I found on the 'net:

IMPORTANCE TO WILDLIFE AND LIVESTOCK:
Prostrate knotweed is consumed by a variety of wildlife species as well as some livestock. However, in Australia, the death of several horses from nitrite toxicity was attributed to eating prostrate knotweed [85].

Palatability and/or nutritional value: Prostrate knotweed seeds are consumed by birds [32,138] including the American coot [14], mallard, killdeer [41], rock dove [114], sharp-tailed grouse [140], California quail [36], and American tree sparrow [12]. Leaves may be consumed by birds [138] such as the sharp-tailed grouse [140]. Small mammals may also consume parts of prostrate knotweed [101]. One black-tailed prairie dog stomach contained >20,000 prostrate knotweed seeds [86]. Eastern cottontails consumed prostrate knotweed in Missouri [87]. Prostrate knotweed is browsed by mule deer [38,75] and pronghorn [161,173]. Insects feed on the seeds [101] and nectar [22].

In Australia, prostrate knotweed is used as a fodder plant for pigs (review by [32]). Free-ranging domestic cattle consumed prostrate knotweed while foraging in ponderosa pine forests in central Colorado [38]. Domestic geese did not feed on prostrate knotweed in feeding trials, even when it was the only food available [170].


So it looks like it might be edible. I just had a big female sulcata in my back yard for about 2 weeks. I imagine she must have eaten this weed because the lawn is full of it. She doesn't show any ill effects.

Here's another bit I found about it. Looks like it binds other minerals to it similar to what spinach does:

Although no specific mention has been made for this species, there have been reports that some members of this genus can cause photosensitivity in susceptible people. Many species also contain oxalic acid (the distinctive lemony flavour of sorrel) - whilst not toxic this substance can bind up other minerals making them unavailable to the body and leading to mineral deficiency. Having said that, a number of common foods such as sorrel and rhubarb contain oxalic acid and the leaves of most members of this genus are nutritious and beneficial to eat in moderate quantities. Cooking the leaves will reduce their content of oxalic acid. People with a tendency to rheumatism, arthritis, gout, kidney stones or hyperacidity should take especial caution if including this plant in their diet since it can aggravate their condition[238].


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## Cowboy_Ken (Sep 4, 2012)

Thanks Yvonne. I've got it growing in small clumps in various areas of my gravel driveway. Very hardy. My Sulcata's found it to be like candy, whereas my Russians wanted nothing to do with it. I'll give it sparingly, 10% or less 1 day out of the month.


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