Saponin Distribution in Angiosperms and its Bearing on their Classification

In this paper the groups of plants in which saponins are reported to occur have been listed, and their relationships shown according to the phylogenetic system of classification of Hutchinson. Steroidal saponins mostly occur in different orders of the division Corolliferae of subphyllum Monocotyledons; they are also present in a few families of Dicotyledons like Solanaceae, Scrophulariaceae, Acanthaceae, etc., but saponins present in these families are somewhat different in their nature. Triterpenoid saponins are mostly distributed in some orders of the division Lignosae of the subphyllum Dicotyledons. In this division, Euphorbiales and related orders, Capparidales and related orders and Rosales and related orders Me important sources. In the division Herbaceae some orders like Garyophyllales and Berberidales are also important sources of triterpenoid saponins. There is a marked affinity among plants containing similar saponins. Hutchinson's classification comes very close to the arrangement based on saponin-content. Some suggestions for modification of the classification in the light of saponin-content has been made. A plea is made that phylogenetic system of classification should take into account the presence of saponins and other chemical constituents.