葉っぱ (happa) means “leaf” | MotiTan Japanese Dictionary

More examples

この葉っぱは緑色です。ko no ha ppa wa midori iro de su

This leaf is green.

この葉っぱの形をよく見てください。ko no ha ppa no katachi o yo ku mi te ku da sa i

Please take a close look at the shape of this leaf.

Refers to the flat part of a plant, either as one separate part or as part of the plant's foliage.

葉ha: A neutral noun for the flat part of a plant, suitable for general use.

植物の茎や枝に付いて広がる、平たい器官。shoku butsu no kuki ya eda ni tsu i te hiro ga ru hira ta i ki kan

葉っぱ (happa) comes from 葉 (ha, "leaf") plus the colloquial ending っぱ (ppa), making it a familiar form of the noun.

In everyday conversation, 葉っぱ (happa) sounds more casual and concrete than 葉 (ha) when speakers talk about a visible leaf or leaves on a plant.