View photos of the medicinal plant Heracleum maximum [Heracleum lanatum] (Cow parsnip), profiled in Medicinal Plants of the Western Mountain States.

A passage from Medicinal Plants of the Western Mountain States:

American herbal doctors of the ninetieth century were keenly aware of Cow parsnip’s value as an antispasmodic sedative. It was considered to have both smooth muscle and nerve pathway affinity. Tics, tremors, and associated spasm due to nerve pathway over–stimulation and trauma are the plant’s best indications. Mild seizure and convulsant activity, particularly if muscular tension and paralysis–like symptoms exist, also suggests Cow parsnip will be of use. More prosaically, the plant can be used as a simple nervous system sedative taken before bed. Here it will be found specifically calming if muscular tension due to stress is a factor in sleeplessness.