This study comprises phytochemical and embryological investigations on 16 genera and 24 species of the three subfamilies: Hydrocotyloideae, Saniculoideae and Apioideae of the family Umbelliferae. Simple phenol and flavonoid aglycone patterns in the subfamilies have been evaluated. Equal attention has been paid to all the embryological aspects and a critical comparative account of the features in the various subfamilies is presented. Interrelationships of the families of Umbellales are discussed in the light of present data as well as the earlier literature on morphology, palynology, anatomy, embryology and phytochemisty. The validity of retaining Cornaceae, Araliaceae, Umbelliferae, Garryaceae, Nyssaceae and Alangiaceae in the order Umbellales is ascertained. Many families created by Takhtajan and Dahlgren appear to be questionable. Proposal of Hydrocotylaceae is ruled out. Merger of the families Araliaceae and Umbelliferae into one family is not favoured on phytochemical and embryological evidences. Derivation of the order Umbellales from Rosales, Rutales and Saxifragales as was done by Van Tieghem, Wettstein, Takhtajan, Hutchinson and Dahlgren was favoured.
