Devillers-Terschuren, J. & Devillers, P. 1995. Epipactis spiridonovii, a new species from Bulgaria. Abstract. Natural. Belges 76 (Orchid. 8): 84.
A new orchid species, Epipactis spiridonovii, is described from the Pirin mountains of south-western Bulgaria. It is a member of the Epipactis atrorubens group, characterized by corrugated decorations on the epichile, strongly pilose upper stem, floral pedicels and ribs of the ovary, red floral pedicels. It differs from all species in the group by large, broad, plane, leaves, from E. atrorubens by smaller, yellow-tinged flowers, from E. parviflora and E. subclausa (E. thessala) by the lack of violet suffusion on the leaves. Stations are located in closed forests of mature Pinus heldreichii and Picea abies-Abies alba-Pinus peuce-Pinus sylvestris, xerophile conifer communities endemic to the region.