Several parts combine into one character.

葉 is a phonetic-semantic compound built from three components: 艹 (grass radical) on top, sitting over 枼 (a stylized image of layered leaves), which itself decomposes into 世 (generation / era) and 木 (tree). The composite poetry is exquisite: a leaf is what a tree puts forth in each new generation. The grass radical reinforces the plant meaning. The mainland simplification took a radical shortcut, replacing 葉 with 叶 — a character that historically meant "to harmonize" (read as xié), but whose simpler form was repurposed for "leaf" via sound borrowing. Today in mainland China, 葉 and 叶 are functionally one character.

Korean reading "yeop." 落葉 (nakyeop, fallen leaves), 葉書 (yeopseo, postcard — literally "leaf-writing," referencing the thinness of a postcard), 針葉樹 (chimnyeopsu, conifer / "needle-leaf tree"), 茶葉 (chayeop, tea leaves). Korean preserves the traditional 葉 form across all written contexts.

Mandarin yè, 4th tone (simplified 叶). 树叶 (shùyè, leaves of a tree), 叶子 (yèzi, leaf), 茶叶 (cháyè, tea leaves), 红叶 (hóngyè, red autumn leaves). The visual leap from 葉 to 叶 is so dramatic that learners moving between traditional and simplified scripts often miss the connection — they look like entirely unrelated characters.

Japanese on-reading ヨウ (yō) — 紅葉 (kōyō, autumn foliage — a major Japanese seasonal word; the autumn colors viewing season is called momijigari), 落葉 (rakuyō, fallen leaves), 葉書 (hagaki, postcard — uses the kun-reading ha + kaki). Kun-reading は (ha) for the leaf itself. The most beautifully metaphorical use is 言葉 (kotoba, "word / language") — literally "speech-leaves," picturing words as small leaves the heart puts forth. This is one of Japanese's most lyrical native compounds, and ko-toba comes ultimately from koto-no-ha ("the leaves of speech").

Memory aid: grass (艹) over generations (世) of tree (木) — what each new generation of a tree extends.