A new subspecies of Teucrium montanum (Lamiaceae) from northern Albania

Morphological and anatomical variation within Teucrium montanum was examined in 322 individuals from 33 populations, representing the two currently accepted subspecies, subsp. montanum and subsp. helianthemoides, as well as three populations of a morphologically distinctive group from northern Albania. A total of twenty-two morphological and twenty-three anatomical quantitative characters were analysed using univariate and multivariate methods, and a further analysis was conducted of the qualitative traits of habitus, indumentum and corolla colour. Selected individuals were cultivated ex situ under uniform conditions to assess the stability of diagnostic traits. The multivariate analyses consistently revealed that the Albanian populations were clearly differentiated from both recognised subspecies. They were characterised by an ascending shrub habitus, elongate, linear-lanceolate leaves with a hook-shaped tip, more than 25 idioblasts (oil cells) per leaf cross-section, and a completely white lower corolla lip. These diagnostic characters remained stable under cultivation. On the basis of the congruent morphological and anatomical differentiation, the Albanian plants, endemic to ultramafic substrates of the Prokletije Mountains around Shkodër, are described as a new subspecies, Teucrium montanum subsp. skadarensis subsp. nov. A key to the subspecies of T. montanum is provided.