| Abbreviation | Definition |
|---|---|
| SDBG | San Diego Botanic Garden |
| SDP | Short-Day Plant |
| SDTF | Seasonally Dry Tropical Forests |
| SDV | Snowy Day Violets |
| SER | Society for Ecological Restoration |
| SF | Self-Flocculating |
| SF | Spreading factor |
| SFAD | Sap Flow Afternoon Decline |
| SG | Seed Growth |
| SG | Seeded Gel |
| SHRB | Shasta Horticulture Resource Bulletin |
| SI | Seed Implantation |
| SIC | Singular Instinct Characteristic |
| SIGNA | Species Iris Group of North America |
| SIR | Soil Insect Rating |
| SIS | Species Information Service |
| SJA | Saint Julian A |
| SLC | Solphonitis Laelio Cattleya |
| SMV | Squash Mosaic Virus |
| SOM | Soil Organic Matter |