Latin: Salix nigra
A “urinary anti-spasmodic.” (Menzies-Trull in "The Herbalist's Prescriber")
An “anti-inflammatory, anti-pyretic, analgesic, antiseptic, astringent. Black Willow is a safe natural source of aspirin-like chemicals, which helps explain its reputation in the treatment of rheumatism and arthritis … and used as part of a wider treatment for any connective tissue inflammation anywhere in the body, … also useful in rheumatoid arthritis.” (David Hoffman in “The New Holistic Herbal”).
By PumpkinSky [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)], from Wikimedia Commons