| Characteristic | Plant hormones | Animal hormones |
|---|---|---|
| Size, chemistry | Peptides, small organic molecules | Peptides, proteins, small molecules |
| Site of synthesis | Usually at many locations | Specialized glands or cells |
| Site of action | Local or distant | Usually distant, transported |
| Effects | Often diverse | Often specific |
| Regulation | By biochemical feedback | By central nervous system, ions, or feedback |