The Chenopodiaceae Tribe Anserineae Dumort was proposed to include the genus Spinacia and the genus Blitum. In addition to the recent domestication of Spinacia, the tribe demonstrates extensive evolution within its floral development. We test whether the development of dioecy, monoecy, and protogyny is reflected differentially among floral developmental versus non-floral developmental genes, and whether recent domestication leaves traces in the phylogenetic relationship within the genus Spinacia. The phylogenetic predictions consistently support the sister relationship of Spinacia sp. to a Blitum clade consisting of Blitum bonus-henricus, Blitum virgatum, and Blitum nuttallianum. Relative rates tests indicate a generally faster rate of nucleotide substitutions within Spinacia. Tests of selection indicate that there is generally purifying selection acting on the sequences. In addition, insertion/deletion (indel) events occur more prominently within the Spinacia clade and occur in both coding and intron regions. The phylogenetic relationships within this tribe calls into question the hypothesis that dioecy in Spinacia evolved from a monoecious grade. The evidence for purifying selection in Spinacia suggests that the increased nucleotide substitution rates are not driving protein evolution, in contrast to evidence of protein sequence and structure evolution driven by indels. There is no footprint of domestication on sequence evolution, and we cannot detect phylogenetic signals that would support separation of the Spinacia accessions into three distinct taxa.