The species Nicotiana tabacum was mated as male with five cultivars of N. tabacum . The inviability of the interspecific F₁hybrids was overcome using cotyledon culture. The viable hybrids were compared with their parents for growth rate, plant morphology and duration of development. The F₁hybrids grew much faster than N. africana and at a rate similar to that of the tabacum parents. The F₁ hybrids produced fewer leaves than their respective parental forms. The hybrid plants were taller than either parent. All hybrid combinations produced bottom and middle leaves which were intermediate in size relative to their parents whereas the upper leaves were larger in the hybrids than in either parent. The bottom and upper leaves of the F₁ hybrids were longer and narrower than those of the cultivated parent whereas the leaf length/width ratio of the upper leaves of the F₁ hybrids did not depart significantly from the corresponding values for the N. tabacum cultivars. The number of days to flower in the F₁ hybrids and in their tabacum parents was similar but N. africana plants flowered much later than both N. tabacum cultivars and the F₁ hybrids. The F₁ hybrids showed much higher variation for the most traits under study than the tabacum cultivars. Likewise, the F₁ hybrids were closer in general habit to the cultivated species. The inflorescence of the hybrids was intermediate in shape, looser than that of the tabacum forms and broader than that of N. africana . The most characteristic morphological traits of N. africana expressed in F₁ hybrids were those involving flower morphology, especially outcurved corolla lobes and exserted stamens.