Hemlady said:The fact that daylily roots are poisonous to humans is surprising to me. Don't the Chinese eat daylilies as part of their diet??? I know I have tried the tubers and boiled them like potatoes just out of curiosity and I didn't get sick.
The Chinese have used the roots for herbal medicines. At least some Chinese researchers are investigating how to make daylilies safer or looking for medicinal replacements that are safe. They do use flowers and/or dried buds as food items.
Poisons are very complicated.
If I asked people to choose whether to drink a cup of caffeine or a cup of trichloroethylene (an industrial solvent) most people would say the cup of caffeine. Unfortunately, caffeine is more poisonous than trichloroethylene. It takes 2.4 g/kg body weight of trichloroethylene to kill 50% of the mice it is fed to but only 0.1 g/kg of caffeine to kill the same proportion of mice.
Some of us drink many cups of coffee, or tea or colas each day. Of course a cup of coffee is not the same as a cup of caffeine. A cup of coffee might have 0.1 g of caffeine. And a person might weigh 70 kg. A person would have to drink 70 cups of coffee in one go to get the dose of caffeine that would kill 50% of the mice. (People might have a different dose that kills 50%, for example the dose that kills 50% of lab rats is 0.2 g/kg body weight).
Second, there is more than one daylily species. The poison has been found in some of the daylily species but it may not be in all of them. Unfortunately, our daylilies were originally created using hybrids of quite a few daylily species. So some daylily cultivars might have the poison and some might not.
The poison might not be in the roots until certain times of the year or it might not be in the roots unless the daylilies have been stressed by heat and no one knows whether the poison is present only some of the time and what might cause it to be present or absent. It is not known what might cause differences in the amount of the chemical in the roots. How many roots would have to be eaten to become ill is also unknown.
Boiling plant parts removes some chemicals - at least some of them dissolve into the water. There are wild plants that can be collected and eaten. The instructions often say to cook the plants in several changes of water to remove/reduce chemicals that might make one sick. Whether the poison in daylily roots is removed by boiling the roots or whether the poison is destroyed by heat is unknown.
I'm very glad that you suffered no ill effects from eating the boiled tubers. I have eaten the flowers once. But I have never done so again after I learned that more than one research group had found poison in the roots and that some people had died. I would never eat any of the tuberous roots.
The poison was first named hemerocallin but is now called stypandrol.