Herbacitrin, the new flavonol glucoside obtained fromGossypium herbaceum (Uppam) has the formula C21H20O12. Though isomeric with Quercimeritrin it differs from it in many properties. On hydrolysis it gives glucose and Herbacetin having the formula C15H10O7 which differs from Quercetin in its reactions. In their colour reactions with alkaline buffer solutions and withp-benzoquinone Herbacitrin exhibits a very close resemblance to Gossypitrin and Herbacetin to Gossypetin. From these and other considerations Herbacetin has been given the constitution 3 ∶ 5 ∶ 7 ∶ 8 ∶ 4′-pentahydroxy-flavone and Herbacitrin is represented as its 7-glucoside. This has been confirmed by the oxidation of Herbacitrin top-hydroxy-benzoic acid. The flavonol has now been synthesised in the Dyson Perrins Laboratories in Oxford and found to be identical with the natural specimen.