Bupleurum longifolium subsp. longifolium

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1981, Flora Europaea. Volume 2. Rosaceae to Umbelliferae, Cambridge University Press : 346

(a) Subsp. longifolium ;

Plant rarely yellowish-green; bracts and bracteoles green, sometimes purplish, very rarely yellowish, scarcely translucent. From C. France to the Carpathians and N. Bulgaria, mainly in mountain regions.