Frequency of branches with outwardly visible branch collars versus branches having pith continuous with trunk pith below the branch union as observed in the medial longitudinal plane of branch unions.
| Collar | Pith connected | ||
|---|---|---|---|
| No | Yes | Total | |
| Red maple | |||
| No | 61z (76.3)y | 19 (23.7) | 80 |
| Yes | 34 (100.0) | 0 (0.0) | 34 |
| Live oak | |||
| No | 41 (67.2) | 20 (32.8) | 61 |
| Yes | 49 (89.1) | 6 (10.9) | 55 |