Tecoma stans foi introduzida no Brasil para fins ornamentais e ocorre tanto cultivada quanto subespontânea. Objetivando avaliar seu potencial alelopático, foi testado o efeito do extrato aquoso de suas folhas sobre a germinação e o desenvolvimento radicial de Lactuca sativa L. (alface), Handroanthus ochraceus (Cham.) Mattos (ipê) e Medicago sativa L. (alfafa). O extrato causou uma forte inibição na germinação das sementes de alface. O desenvolvimento radicial de alface e alfafa foi reduzido em 75 e 30%, respectivamente. Não foi observado efeito do extrato sobre a germinação ou o desenvolvimento radicial do ipê. Todas as espécies tiveram a velocidade de germinação reduzida. Observaram-se alterações micromorfológicas no ápice radicial das plântulas de alface.

Tecoma stans was introduced in Brazil for ornamental purposes and occurs both as a cultivated or sub-spontaneous plant. This study aims to evaluate the allelopathic potential of the aqueous leaf extract of Tecoma stans on the germination and root development of three plant species: Lactuca sativa L. (lettuce), Handroanthus ochraceus (Cham.) Mattos (ipe), and Medicago sativa L. (alfalfa). The aqueous leaf extract of Tecoma stans caused strong inhibition on lettuce germination. The seedlings of lettuce and alfalfa had their root development reduced by 75% and 30%, respectively. There was no effect of the extract on the germination or root development of ipe. Also, the germination rate of the three species tested was reduced. Micromorphological changes were observed in the root apex of lettuce seedlings.

Our solemn homage to the great Master Otto R. Gottlieb who knew how to teach the mystery of evolutionary relationships between chemistry and its natural sources. The micromolecular chemical study of the family Bignoniaceae shows a profile predominantly characterized by the occurrence of metabolites derived from acetic acid biosynthetic pathways such as terpenoids, quinones, flavonoids and special aromatic derivatives. Analysis of different chemosystematic parameters for the metabolite data collected, provided valuable information for the systematic characterization of the Bignoniaceae family within the Angiosperm derived taxa.