Cone morphology variation in Pinus canariensis Sm.

Morphological variation of Pinus canariensis cones was studied, based on a sample of 891 cones collected at 23 populations covering the entire natural range of distribution of the species. Both categorical and quantitative traits were used for the analyses. The categorical traits of the apophysis and umbo were subjected to Multiple Correspondence Analysis (MCA). The categories related to apophysis type were found to be the most important variables for ordination. Three cone groups were defined through clustering, generally differentiated according to apophysis prominence. Approximately half of the studied cones were classified within one group, denominated form gibba and corresponding to the majority of previous descriptions of the species. In addition, we found some other, less frequent cone forms (called plana, gibberosa protuberans and reflexa), which have not been traditionally considered in Pinus canariensis. Cones and seeds were larger in stands at higher altitude, possibly adapted to unfavourable (cold and dry) environment. No clear geographical structure was found in the studied traits at the population level. However, variation of cone morphology among islands was found to be related to the extension of pine forests.