Seven nuclei of Tradescantia sp. (2n=12) were prepared using Gillies' modification of the Counce-Meyer whole-mount spreading technique. These nuclei were examined for the type (homologous and nonhomologous), amount, and location of synaptonemal complex (SC) formation. Estimates of the total potential number of discrete initiations of SC formation ranged from 251–299 per nucleus. The average distance between sites of initiation ranged from 7.3 to 11.2 μm in the different nuclei. Two groups of Tradescantia were used. Of the T. ohiensis var. paludosa plants, the one instance of irregularity in synapsis was associated with a pairing partner switchpoint. In the other plants derived from Mericle's Clone 02, all nuclei, even those in early zygotene, had several examples of foldback synapsis. The significance of the location of SC formation, and the occurrence of foldback synapsis is considered and a model of SC formation is proposed. In this model, a “recognition of homology” step is not considered necessary for SC formation; homologous synapsis is usually accomplished by spatial and temporal coordination of zygotene DNA synthesis.