Interspecific hybridization in Tecoma Juss. was conducted to develop novel forms for the nursery industry. We report fertile hybrids from the cross T. garrocha Hieron. (pistillate parent) × T. stans (L.) Juss. ex Kunth. Leaf morphology of the F₁ hybrids of T. garrocha × T. stans was intermediate between the parents. GISH also confirmed hybridity. The F₁ hybrids were successfully backcrossed to both parents and self-pollinated to produce BC and F₂ progeny. Tecoma garrocha, T. stans, and T. guarume A. DC. ‘Tangelo’ were self-fertile. The F₁ hybrids also were crossed with T. capensis (Thunb.) Lindl. and T. guarume ‘Tangelo’, resulting in three-species hybrids. FISH conducted on F₁ hybrids identified four copies of the 18S internal transcribed spacer region. Further analysis using FISH has the potential to provide information on the evolution of Bignoniaceae and the potential role of polyploidy.