A new combination for a neglected member of Linaria subsect. Versicolores (Plantaginaceae, Antirrhineae) endemic to the Algarve, Portugal

Abstract

Linaria bimaculata comb. et stat. nov., from the overlooked Central Algarve plant endemism centre, is here lectotypified and redescribed as a full species based on Linaria viscosa var. bimaculata, which was historically misidentified under allopatric L. spartea and L. viscosa. Traditional herbarium taxonomy and citizen science observations were combined to document the geographical range of the four species of Linaria subsect. Versicolores in the Algarve and amend an identification key for the Iberian clade of this subsection. Geographical patterns and morphological similarity suggest a sister relationship between L. bimaculata and L. algarviana, unveiling a new possible example of parallel speciation linked to a purple to yellow shift in corolla colour. Besides the yellow flowers, L. bimaculata differs from L. algarviana in the more elongate fertile stems and the invariably erect-patent corolla tube. It is assessed as Vulnerable (VU) according to the IUCN Categories and Criteria.