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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: Can the cold weather kill off Fiddleneck?

I was very fortunate in pulling my horse through Fiddleneck weed (amsinckia intermedia) poisoning two years ago. The problem is every year I need to pull my horse off of the pasture when the Fiddleneck weed comes back in the springtime (since it continues to grow abundantly in the pasture where I board my horse in the San Francisco bay area in California). When I review the poisonous plant web page (which is GREAT I might add!), it appears that it is the SEEDS in the flower that are poisonous. Are the green portions of the plant fairly inert? If that is the case, I do not need to pull my horse off of the pasture until I start to see the flower buds. In fact, this year, I have not seen any Fiddleneck weed thus far and wonder if all of the cold weather (several freezing nights in a row, but no snow) has killed off the Fiddleneck. Is this possible?


I am from Northern California (just been here 4 1/2 years), so I am pretty familiar with your fiddleneck. Unfortunately, the whole plant contains the pyrolizidine alkaloids. Your horse recovered, but may still be sporting a little liver damage, so please don't expose him/her to it again, if practical. The damage tends to accumulate, although the liver can repair itself to a great extent. Fiddleneck thrives in recently disturbed sites, but can be outcompeted by other species over time. Your cold weather may have helped.