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"Poisonous" does not mean deadly. Some manifestations of toxicity are subtle. The dose, as always, determines if a plant is safe source of nutrients or a toxic hazard.

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BRIEF: Are these plants, indigenous to S.D., poisonous to humans as well as livestock?

I am keenly interested in indigenous plants toxic to humans (Western South Dakota). I have a list of plants poisonous to livestock found in the Great Plains areas. I am trying to cross reference this list with plants known to be toxic to humans, but I'm not sure how comprehensive it is (Wilderness Medicine, Auerbach, ed, 1995). Could you tell me if the following plant species are toxic to humans (sorry for any inappropriate nomenclature)? Would you suggest the best source of poisonous plant photographs to produce slides of ? Crazyweed, lambert & white point (Fabaceae family) Greasewood (Goosefoot family) Houndstongue (Borage family) Kochia (Goosefoot f.) Milkweed, Whorled


The best source of poisonous plant photographs is your camera and local plants. Given your regional interest, it might be your best bet. >Crazyweed, lambert &white point (Fabaceae family) - Some are, some aren't, depends on the specific species. Some accumluate selenium, some have toxic alkaloids, some have some killer nitroso compounds, some have lectins, it just depends on the species. The problem with specific documented human poisoning accounts is that the species is not always well known and the taxonomy is diverse. Most of the toxins found in the various astragalus have been found to be toxic to humans in other contexts. >Greasewood (Goosefoot family) and >Kochia (Goosefoot f.)- Both have tons of oxylates in them, but if used by humans, I imagine it would be as a spice for the sour flavor. I am not sure at all if these are really a threat unless we ate whole salad bowls full of them. they cause problems in livestock because they eat a lot and find their blood calcium levels in the basement. Chronic ingestion can cause kidney problems, too. Would or can people eat enough over a long period of time to suffer these symptoms? I don't know. >Houndstongue (Borage family) - This plant has pyrrolizidine alkaloids capable of damaging the human liver and should not be used internally. >Milkweed, Whorled - I have never read of any human poisoning from this species, but it contains sufficient cardiac glycoside to make cattle sick and worse. it tastes nasty enough so that one would think that only a gonzo herbal nut would eat enough to do harm.