Cannabis is different in the sense that it is the only plant I ever grew to harvest the flower.
Unfertilized, female, matured flower is the desired product.
Seeds would be the 'fruit' or crop usually, but with medical cannabis you want to avoid seeds at all cost.
The desired cannabinoids are really a stress response of the female flower.
But too much stress can cause the female plant to express male flowers, which is also very undesirable...
I am trying to ride the edge here; stress is good, but too much can result in disaster...