极

Tree radical on the left - pictograph of a tree with branches above and roots below. 极 originally named 'the ridgepole of a roof' - the topmost beam, the wooden apex of a house. From 'topmost wooden beam' came the modern senses 'extreme, utmost, pole'. Same radical heads 木 family 林 forest, 树 tree, 杂 mixed, 桥 bridge.

Right side 及 supplies an exact phonetic match: jí → jí, no drift. 及 itself depicts a hand reaching to grasp a person - to overtake, to reach. Carries strong semantic resonance: 极 is what you 'reach' at the limit, the top beam, the very end. Same phonetic also gives 级 (rank), 急 (urgent), 吸 (inhale).