Frequently (and not so frequently) Asked Questions
BRIEF: Are these plants, indigenous to S.D., poisonous to humans as well as livestock?
QUESTION:
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
ANSWER:
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.