From topology to biological meaning: why plant family classification matters beyond systematics

Plant family names are routinely used to structure comparative analyses, trait databases, floras, conservation assessments, and teaching. Yet, these names are not neutral labels: changing family boundaries changes the units across which biological patterns are compared, summarized, and interpreted. Modern phylogenetic inference resolves evolutionary relationships with increasing confidence, but it does not by itself determine which monophyletic groups should be recognized as families. We argue that this choice should be guided not only by monophyly, but also by diagnosability, biological interpretability, stability, and practical utility. Recent debates around large-scale consensus classifications show why these criteria must be explicit. Recognizing classification as shared scientific infrastructure means that family delimitation matters not only to systematists, but to all plant scientists who rely on taxonomic units to formulate questions and communicate results.