Taxus baccata in the Azores: A relict form at risk of imminent extinction

Abstract

Taxus baccata L., a Tertiary relict formerly widespread in the Azores Archipelago, was recently classified as "probably extinct". This paper documents the persistence of the species in the Azores and provides its first characterization by means of morphometric and genetic analyses. Only five individuals were found, growing on Pico Island. Although the population size is critically small it retains some highly significant characteristics for the assessment of the genetic diversity of the species and its phylogeography. The leaves of the Azorean provenance were smaller than those of all other Taxus baccata described in literature; moreover, they have a higher stomata density and more numerous stomata rows. These features are all "primitive", according to suggested morphological evolutionary trends. We assume that sequence analysis of the chloroplast trnS-trnQ intergenic spacer demonstrates that the Azorean population represents a different evolutionary line within Taxus. This suggests a more direct derivation from ancestors than provenances from Mediterranean and European regions. These individuals may be the last survivors of an ancient lineage, preserved in the Azores as part of the Macaronesian flora. Immediate conservation action focusing on site protection and ex situ reproduction strategies is recommended to save this lineage from imminent extinction. © 2010 Springer Science+Business Media B.V.