In the United States,
Senecio vulgaris has been listed as a
noxious weed, being both
non-native to most if not all of the Americas and having a reputation for being
hepatotoxic to
livestock and to
humans.
Toxic versus medicinal ;Human As a plant that is reported to be both
poisonous for humans and also
medicinal, much of the contradiction can be found by closely reviewing the words that are used and the dose (amount) of the poisonous substance that is ingested to prove either claim. All species of the genus
Senecio contain
pyrrolizidine alkaloids (e.g.,
senecionine), a substance that when a human has chronic exposure can cause irreversible liver damage. Common groundsel as a medicinal herb does not seem to have been recommended very often since 1931, when it was recommended as a
diaphoretic, an
antiscorbutic, a
purgative, a
diuretic and an
anthelmintic, which was a demotion as it was previously suggested for the expelling of
gravel of the kidneys and reins by
Pedanius Dioscorides in the 1st century, for use as
poultices by
John Gerard in the late 16th century and as a cure for
epilepsy by
Nicholas Culpeper in the 17th century. Certain pyrrolizidine alkaloids are non-toxic precursors that are converted to toxic
metabolites in the body in a process called
toxification Botanist and noted authority on plant lore
Albert Roy Vickery quotes a 1991 account of the use of groundsel as a highly effective purge in the English county of
Dorset: Mr Joby House, who used to be at
Hewood, told us that, for
constipation, you boiled groundsel and
lard and take that and you will
shit through the eye of a needle. His sister Lucy had
constipation so bad that when the doctor called in the morning he said Lucy would be dead by 5 o'clock. Mrs. House went to the
gypsies (Mrs. Penfold)...and she told her how to cure her. The doctor came late in the day, and Lucy was running around; there was
shit everywhere. The doctor had brought Lucy's
death certificate, but he was so mad he tore it up and put it in the fire. ;Livestock
Carl Linnaeus is cited to have claimed that "
goats and
swine eat this common plant freely,
cows being not partial to it and
horses and
sheep declining to touch it, but not only are
caged birds fond of it (the
seeds), but its leaves and seeds afford food for many of our wild species (
rabbits were given as an example)." The alkaloids responsible are not destroyed by drying or by fermentation in silage. There is evidence that it is not a strong invasive and sometimes protective of critically endangered native plants. The approximately long
pappus seeds of
Senecio vulgaris, each plant capable of producing 25,000 or more seeds (1,700 seeds per plant are more likely) with three generations of the plant per year; have been identified as a contaminant of cereal and vegetable seeds One study showed that rust fungus infected
Senecio vulgaris survived and actually used more of the available soil nutrients. The cinnabar moth eats groundsel between June and August, but the seeds germinate and the plant grows as soon as the ground is warm enough (and after a warm rain),
carrots and all other non-grass crops. There is also evidence that the plant develops an
immunity to the chemical control. ;Other Groundsel seedlings with 2–6 leaves are tolerant of
flame weeding but the seeds are susceptible to
soil solarization. ==See also==