JUVENILITY AND MATURITY IN PLANTS

Although maturation is most commonly associated with animal aging or human emotional development, it also finds its place in plant sci­ence. Most commonly observed as a morphological (structural) change in the plant, it can also be manifested as a change in flowering or fruit­ing habit, or in its mode of growth.

Juvenility is a state of vegetative growth during which a plant can­not flower. In annual plants, this state is very short (perhaps a month or two), whereas in longer-lived species, a healthy, actively growing plant may exist in the juvenile stage for years. Maturity is the state of growth during which the plant becomes capable of flowering. Localized mer – istematic growth makes it possible for some plants to produce juvenile cell growth and mature cell growth simultaneously.

While the unseen changes that must necessarily occur in the plant to initiate its change of state from juvenile to adult are still not entirely understood, the physical evidence of change is often striking. English ivy (Hedera helix) in its juvenile state is a trailing vine with deeply lobed leaves. Many people do not recognize it at maturity because the leaves become unlobed (entire) and the plant easily supports itself for upright growth. Philodendron leaves have an opposite appearance; that is, unlobed when juvenile and lobed when mature. Oak trees (Quercus species) retain their dead leaves through much of the winter as long as the tree is in its juvenile state. Old oaks drop their leaves much earlier.