Adventitiousness

Adventitious has various meanings in various disciplines and in general usage.

Adventitious is from the Latin root advenire, meaning "to come or be superadded" and in correct English the meanings tend to have connections to accidental or casual occurrence. "...of the nature of an addition from without; supervenient, accidental, casual.

People sometimes speak of an event or occurrence as being "random", when the word "adventitious", or perhaps "accidental", might be more strictly correct.

Botany

In botany, adventitious refers to structures that develop in an unusual place. This part of the article discusses adventitious roots, buds and shoots, which are very common in vascular plants.

Buds and shoots

Adventitious buds develop from places other than a shoot apical meristem, which occurs at the tip of a stem, or on a shoot node, at the leaf axil, the bud being left there during the primary growth. They may develop on roots or leaves, or on shoots as a new growth. Shoot apical meristems produce one or more axillary or lateral buds at each node. When stems produce considerable secondary growth, the axillary buds may be destroyed. Adventitious buds may then develop on stems with secondary growth.