Bourbon geranium (Pelargonium x asperum), steam-distilled from the aerial parts of plants cultivated on Réunion island (historically known as Île Bourbon), is dominated by the oxygenated monoterpenes β-citronellol, geraniol, and their corresponding formate esters, with isomenthone levels that vary with altitude and temperature during the growing season.^[1] The oil is distinguished from other geranium origins by sesquiterpene markers including guaiane-type components, and its high citronellol-to-geraniol ratio has been linked to characteristic rose-like aromatic quality.^[1]