sentence: All the members with one-seeded fruits arranged their embryos vertically , and many Chenopodiaceae representatives of different taxonomic position evolved a horizontally oriented embryo as a synapomorphy.Unique , taxonomically important carpological characters justifying family rank have been proposed for Achatocarpaceae ( polystarch grains in the seeds ) and Sarcobataceae ( general pericarp structure ) , and also for Seguieriaceae and Petiveriaceae ( pericarp structure ) , the latter previously being considered part of Phytolaccaceae .