Variation patterns in the Phlomis x composita (Lamiaceae) hybrid complex in the Iberian Peninsula

Hybridization seems to be common in the genus Phlomis (Lamiaceae) in the Iberian Peninsula, especially in the R x composita complex. In order to detect patterns of morphological variation linked to eco- and geographical variation, ecological (cluster and canonical correspondence) and morphometric (principal component and discriminant function) analyses were performed. Character count procedure was applied to discern between divergence and reticulate events for the origin of the morphologically intermediate plants. Following these analyses clear patterns were detected suggesting the existence of four independent morphological groups also supported by the ecogeographical data. These are R crinita ssp. crinita (Levante, eastern Spain), P. crinita ssp. malacitana (Andalusia, southern Spain) and R lychnitis (widespread) being the extremes of the morphological variation, and R x composita including all the morphologically intermediate individual plants. Furthermore, at the population level significant differences in hybrid plant frequencies between areas were also found. (C) 2004 The Linnean Society of London,.