Know the difference between the two? When you see genus think: generic. In botany, a genus (plural genera) is a taxonomic rank grouping multiple, closely related, and similar species that are thought to have come from a common ancestor. When you see species think: specific. A species is a taxonomic rank representing a group of similar organisms with shared characteristics that can reproduce and produce fertile offspring. The naming of plants has two parts: first the genus then the species. Example: Philodendron Micans.