Orientation of Paired Leaves in Grapevines and Related Species
| Species | Total leaf pairs examined | Pairs with opposite-side orientation | Pairs with same-side orientation | Ratio of opposite-side orientations to same-side orientations (n to 1) |
|---|---|---|---|---|
| Vitis labrusca | 383 | 287 | 96 | 2.99 |
| Vitis rupestris | 303 | 201 | 102 | 1.97 |
| Vitis amurensis | 207 | 146 | 61 | 2.39 |
| Vitis × andersonii | 10 | 9 | 1 | 9.00 |
Many plants have leaves that are larger on one side of their long central axis than the other, a phenomenon known as asymmetrical orientation. University of California, Berkeley biologist Ciera Martinez and colleagues examined several species of grapevines and closely related plants which have leaves that display this asymmetry. They found that in most species examined, the ratio of opposite-side orientations to same-side orientations was