African Geranium (Pelargonium sidoides): traditional use for respiratory infections, root preparation, contraindications, and drug interactions.

Silver Birch (Betula pendula): traditional uses, tea and sap preparation, contraindications, and the pollen's cross-reaction allergy risk.

White willow (Salix alba): traditional uses, bark decoction preparation, and contraindications for Reye's syndrome, salicylate allergy, and anticoagulants.

Goldenseal (Hydrastis canadensis): traditional uses, phytochemical profile, preparation methods, and contraindications for this berberine-rich rhizome.

Oregano (Origanum vulgare): aromatic Lamiaceae herb; see traditional uses, tea and oil preparation, synergies, and contraindications.