Stem Elongation The lengthening of the Plumeria stem, influenced by genetics and environmental factors. Synonyms: Growth in LengthRelated Articles: Glossary: Gibberellin HormoneUsing gibberellins to regulate growth and flowering in Plumeria.Glossary: GibberellinsGibberellins are a group of plant hormones that play key roles in regulating various aspects of plant growth and development.