expression, noun
Refers to any tree of the palm family (Arecaceae). The phrase is a common, everyday term.
See also: ヤシ
ビーチにヤシの木が並んでいる。
Palm trees line the beach.
この島にはヤシの木がたくさん生えている。
Many palm trees grow on this island.
ヤシ means 'palm' (the plant family or tree) and can be used alone, while ヤシの木 explicitly means 'palm tree' and is more common in everyday speech.
Compound of ヤシ (palm) + の (possessive particle) + 木 (tree). ヤシ is likely from Portuguese 'palma' or Spanish 'palma', but the exact derivation is uncertain.