葡

Top grass radical (3-stroke form) - the indexing component. Marks 葡 as a plant character, here a fruit-bearing vine. Anchors the word 葡萄 'grape' in the botanical family (花, 草, 茶, 莲, 苹 apple). Both syllables of 葡萄 carry the 艹 top, a sign that the compound is a true plant name borrowed wholesale.

Bottom 匍 supplies the sound - pú level-tone, no drift. Pleasingly, 匍 means 'to crawl, creep along the ground,' a perfect description of how a grapevine actually grows; so the phonetic doubles as a faint semantic hint. 葡萄 is a Han-era loanword from a Central Asian language (likely Bactrian), written with these two sound-tagged plant characters.