DENDROLOGY

Detailed explanation-1: -The prefix “di-” means two. A dichotomous key breaks down identification into two mutually exclusive options at each step.

Detailed explanation-2: -All parts of the key should be dichotomous. Never use trichotomies. Always give contrasting, alternative characteristics in each couplet. Use clear-cut opposites.

Detailed explanation-3: -“Dichotomous” means, “divided into two parts.” A dichotomous key always gives two choices in each step. In each step, you must make a decision based on characteristics of the item. If you decide correctly every time, the name of the item will be revealed at the end.