A vertical D3.js tree presents a four-level classification of plants, from a root node through major groups (Angiosperms, Gymnosperms, Ferns, Mosses) to families and genera. Node color encodes the plant group, while shape distinguishes hierarchy: circles for root, diamonds for groups, squares for families, and triangles for examples. Hovering reveals tooltips bound to the DOM event. The SVG renders data from flat rows using `d3.stratify`, with a legend and self-tests included in the static layout.