Results show the feasibility of regenerating rooting Bidens alba plants from nopaline-type crown galls incited by Agrobacterium tumefaciens containing pTi-T37. Transmission of the tumour marker nopaline synthesis is demonstrated into the fourth generation but decreases in level of expression or loss of the trait occurs. Nopaline synthesis and auxin autotrophy, as markers, can also be differentially lost, making it difficult to demonstrate Mendelian inheritance. Formation of octopine-type tumours on nopaline positive plants occurs in a high percentage of inoculations. Transformed plants show several morphological traits which distinguish them from normal plants: they are smaller, have decreased apical dominance, show hypertrophy of the hypocotyl region, lower nodes, and petiole bases, and frequently form an extra spur of tissue in ray flowers.