Crampbark
Crampbark is a fruiting shrub found in the Eastern lands bordering the Inner Sea... it is most common in Calin and Miwoc, but can also be found in Lookshy, Tien-Wo, Ceben and Valis.
Its bright red berries are very acidic and mildly poisonous. The Calinti use them to make a jam, but their toxicity means consuming too much of this, or too many of the berries themselves, can induce nausea and diarrhea.
More valuable than its fruit is its bark, which can be worked into poultices or brewed into teas which provide relief from cramps. Crampbark is harvested and exported, with Calin supplying the River Province and Realm satrapies the Blessed Isle, where teas are widely distributed amongst the common folk by the Benevolent Stewards of Health and Utility, to relieve muscle and menstrual pains.