Abstract The phenomenon of phenotypic plasticity, whereby genetically identical plants when grown in variable environments exhibit alterations in growth rates or patterns of growth, has been observed as morphogenic expression of plants or plant parts cultured in vitro. Plastic responses to sub- and supra-optimum temperatures for survival, growth and induction of rooting in vitro were observed in shoot explants of Pinus carribaea derived from ecologically diverse sources. The ability to form roots did not correspond with their ability to survive and grow under a range of temperatures. As both these characters are important for field performance, the plastic responses of characters and interactions between them are important considerations for selecting plants. In vitro procedures provide rapid and efficient means for early detection of these differences.