4-Chloroindole-3-acetic acid (4-Cl-IAA) is a natural plant hormone. It is a member of the class of compounds known as auxins and a chlorinated derivative of the more common auxin indole-3-acetic acid (IAA). 4-Cl-IAA is found in the seeds of a variety of plants, particularly legumes such as peas and broad beans. It is hypothosized that 4-Cl-IAA may be a "death hormone" that maturing seeds use to trigger death of the parent plant by mobilizing nutrients to be stored in the seed.