The science of plant morphology: Definition, history, and role in modern biology

As a scientific discipline, plant morphology is 211 yr old, originated by G oethe in 1790. It is a discipline that has largely been Germanic in practic e. Because it took its origins from the study of the natural history of pla nts and the United States is principally an engineering society, the discip line of plant morphology in its pure form has never been widely practiced i n this country. What has been labeled "plant morphology" in the United Stat es has served largely as a handmaiden for systematics, using morphological characteristics to carve up diversity into its systematic subunits. Because the heart of plant morphology as a science is a focus on the convergences rather than the homologies in a phylogenetic sense. the German tradition of plant morphology is a unifying science that focuses on fundamental themes that transcend systematic boundaries. This paper traces the history of the science of plant morphology through the lineage of its principal practition ers: Goethe, Hofmeister. von Goebel, and Troll. It also evaluates the princ iples of plant morphology by applying them to the phyletically diverse Pter idophytes, showing that contemporary members of that group exhibit levels o f shoot organization comparable to that of seed plants and discusses the im plications of these findings.