Refers to the seed of the hemp plant. Often used in contexts of food, oil, or bird feed.
麻の実は栄養価が高い。
Hemp seeds are highly nutritious.
I give hemp seeds to the small birds.
Compound of 麻 (asa, 'hemp') + の (no, possessive particle) + 実 (mi, 'seed'). The reading is a straightforward combination of the individual readings.