phytonomy: the laws that govern the coming into existance and growth of plants.
Abscission, (from Latin abscindere, from ab- ‘off, away’ + scindere ‘to cut’) is the shedding of a body part.
Monocarpic plants are those that flower, set seeds and then die. Other terms with the same meaning are hapaxanth and semelparous.
Polycarpic plants are those that flower, set seeds and grow fruit many times. Other term with the same meaning is iteroparous.