Vascular variants in seed plants – a developmental perspective

Abstract Over centuries of plant morphological research, biologists have enthusiastically explored how distinct vascular arrangements diversified. These investigations focused on the evolution steles and secondary growth examined diversity tissues (xylem phloem), including atypical developmental pathways generated through modifications to typical development ancestral ontogenies. A shared vernacular has evolved for communicating alternative ontogenies in seed plants. Botanists traditionally used term “anomalous growth” which was later renamed “cambial variants” by late Dr. Sherwin Carlquist (1988). However, can be vague meaning since it is applied that do not necessarily originate from cambial activity. Here, we review concept propose “vascular as a more inclusive overarching framework interpret In this framework, variants are defined their origin (instead anatomical patterns), allowing classification into three categories: (1) procambial variants, (2) (3) ectopic cambia. Each category includes several patterns. Vascular represent broader developmental-based groups, both extant fossil plants, thereby offer adequate an evolutionary perspective. An overview phylogenetic distribution across selected plants provided. Finally, implications discussed.