Pinus × sondereggeri is the only named southern pine hybrid. Common names include Sonderegger pine and bastard pine. It is a naturally occurring cross between loblolly pine (Pinus taeda) and longleaf pine (Pinus palustris). It was originally described by H. H. Chapman (1922) who named it after its discoverer, V. H. Sonderegger, a state forester of Louisiana. This pine usually occurs singly or in small groups where both loblolly and longleaf pines overlap in range. Because the flowering of both parental trees usually occur at the same time of year, no phenological barrier exists, thus the two freely cross.