young barley leaves; barley grass
Refers to the young green leaves of the barley plant, often used in health supplements, juices, and powdered greens.
I mix barley grass powder into my smoothie and drink it.
若葉 means 'young leaves' in general, while 大麦若葉 specifically refers to young barley leaves.
大麦 is the barley grain or plant; 大麦若葉 is specifically the young leaf stage.
Compound of 大麦 (barley) and 若葉 (young leaves).