Stem colour
Royal Horticulture Society (RHS), colour codes are given in parentheses beside descriptor states
| Code | Term | Description |
|---|---|---|
| 1 | Green | Yellow-green group 144B |
| 2 | Sun red | Greyed-red group 178B |
| 3 | Purple | Greyed-purple group 183A |
| 4 | Dark Purple | Greyed-purple colour 187A |