Count the ascending division level, starting from rachis (as 0), then the mid-rib of pinna (if present), and then the mid-rib of pinnule (if present), and so on.

At the highest division level, if a leaflet is observed, then the frond is described as “(division level)-pinnate”. If a segment from a deeply divided leaf blade is found, then it is described as “(division level)-pinnatifid”.