Albino cell suspension cultures were established from chlorophyll-deficient mutants of both species (both 2n = 48). Following fusion induced by polyethyleneglycol between protoplasts from the two cultures, numerous colonies of green cells appeared. Since these colonies did not appear when protoplasts from the same culture were fused or when protoplasts from both cultures were cultured together without fusion, genetic complementation for chlorophyll synthesis is presumed to have occurred in the hybrid cells. The green colonies could readily be induced to form shoots and in some cases roots. Twenty-five hybrid-cell lines later flowered and displayed a range of flower and leaf morphology which was generally intermediate with respect to the parents. Hybrid fertility was low and chromosome complements ranged from 68 to 96. Isozyme analyses of esterase, aspartate transaminase and superoxide dismutase confirmed that the plants were hybrids.