Linaria biebersteinii, Besser

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1972, Flora Europaea. Volume 3. Diapensiacea to Myoporaceae, Cambridge: Cambridge University Press : 232

36. L. biebersteinii Besser , Enum. Pl. Volhyn. 25 (1822).

Stems erect, simple or branched above, sparsely hairy. Leaves 25-55 x 1-5-7 mm, linear-lanceolate, 1- to 3-veined, acute, crowded. Racemes with (2-)5-30 flowers, rather short and dense; pedicels 1-5-7 mm, usually glandular-puberulent or -pubescent; bracts equalling or exceeding pedicels. Calyx 2-5-5 mm, often pubescent; lobes lanceolate, acute. Corolla 20-25(-28) mm, bright yellow; spur 5 -10(—12) mm, stout, wider and shorter than lower lip of corolla. Capsule 6-9 mm, ovoid-oblong or -globose. Seeds 1-7-2-5 mm; disc tuberculate. Steppes. • S. part o f U.S.S.R. Rs (C, W, K, E).

Plants similar to 36 but entirely glabrous and with leaves 3-10 mm wide occur throughout its range, and also in Romania and Hungary. They have been called L. x kocianovicii Ascherson, Österr. Bot. Zeitschr. 15: 367 (1865) (L. angustissima subsp. kocianovicii (Ascherson) Sóo ), and interpreted as hybrids between 15 and 34; but they have also been interpreted as variants of 34 or 35, or as an independent species (L. ruthenica Blonski, L. rudis Janka ).