Field observations of longleaf pine seedlings to examine possible hybridizationThis article is part of a larger document. View the larger document here.
Stem elongation in the nursery is the traditional and accepted indicator that hybridization between longleaf pine (Pinus palustris) and loblolly pine (P. taeda) has occurred. These hybrids, known as Sonderegger pines (P. x sondereggeri), are reported to have distorted limb structure and low-quality wood. As a result, landowners avoid using them. Recently, a large number of longleaf pine seedlings grown in a nursery from particular seedlots displayed unusual stem elongation and were assumed to be Sonderegger pines. It was determined that long-term observations of their development were necessary. Seedlings that displayed true longleaf pine morphology, stem elongation but with atypical longleaf or Sonderegger pine morphology (suspected hybrids), and true Sonderegger pine morphology were outplanted in arranged plots. After assessing the current measurement data, there is no indication that the suspected hybrids are Sonderegger pines. The trees will continue to be monitored for many years to see if their development corresponds to what is known about true longleaf pine or true Sonderegger pine morphology.