Cotyledons and primary needles in loblolly pines (Pinus taeda L.) of Bastrop County, Texas, provenance have morphological modifications which should tend to conserve moisture during drought. FOREST SCI. 23:33-36.
Bilan, M. Victor, "Cotyledon and Primary Needle Variation in Loblolly Pine From Mesic and Xeric Seed Sources" (1977). Faculty Publications. 358.