The resinous exudates of Australian Xanthorrhoea (Liliaceae) ("blackboys") contain a complex mixture of aromatic compounds. From the commercial resin of X. oreissii, naringenin and what is probably its 5-methyl ether were extracted. The caustic-soluble main fraction, after methylation with methyl sulphate and potassium carbonate in acetone and chromatography on alumina, yielded a substance C₁₈H₂₀O₄ (I). Spectroscopic (ultra-violet, infra-red, p.m.r., mass) analysis and comparison with the authentic sample confirmed the structure of (I). (I) is optically inactive, the first flavan derivative to be obtained from natural sources not containing an oxygen attached to the heterocyclic ring (those already known having oxygen at the 3 or 4 or the 3,4-positions). It is unstable to light and air, darkening to a red resin; the phenol precursor is probably more unstable and some at least of the red plant resin may arise from it. The pigments dracorubin and α-dracorhodin probably arise by oxidation of a similar flavan; possibly the red Xanthorrhoea resins contain similar oxidation products.