Carduus uncinatus, Bieb.

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1976, Flora Europaea. Volume 4. Plantaginaceae to Compositae (and Rubiaceae), Cambridge University Press : 226-227

24. C. uncinatus Bieb. , FI. Taur.-Cauc. 3: 553 (1819).

Biennial up to 50 cm. Stemwhite-tomentose; wings up to 7 mm, palmate, with an apical spine up to 5 mm. Leaves oblong-lanceolate, densely hairy above, greyish-tomentose beneath, with straight unicellular hairs, with 6-8 pairs of oblong lobes, each with an apical spine up to 3 mm. Capitula 30-40 mm in diameter, subglobose, mostly with peduncles up to 10 cm and 2 mm in diameter; outer andmiddle involucral bracts more or lessrecurved in distal I, 1 -5-2 mm wide at the base, linear-lanceolate, flat, arachnoid-hairy, the mid-vein raised throughout its length; inner bracts 1| times as long as the inner middle bracts, 1-veined. Corolla 21-23 mm. Achenes 3-4 mm, compressed, rugose; apical prominence sessile, entire; pappus 10-13 mm. Dry grassland. S. part of U.S.S.R., S.E. Romania.?Bu Rm Rs (W, K, E)?Tu.

C. uncinatus subsp. davisii Kazmi , Mitt. Bot. Staatssamm. (München) 5: 404 (1964), was described from a single specimen collected on calcareous rocks in Krym (above Nikita). It is readily distinguished from 24 by the glabrescent leaves, longer peduncles, outer and middle involucral bracts strongly deflexed at the middle and abruptly narrowed into a long subulate apex, corolla 26-28 mm and pappus 20-22 mm. It seems related to 23 but further investigation is needed. (25-27). C. defloratus group. Perennials up to 100 cm. Stem glabrous to more or less arachnoid-hairy; wings palmate or triangular, dentate. Leaves obovate to oblong-lanceolate, glabrous or with very sparse, crispate multicellular hairs. Capitula 20-30 mm in diameter, subglobose; peduncles up to 35 cm and 2-5 mm in diameter; involucral bracts 1-2 mm wide at the base, imbricate but the outer and sometimes the middle patent to deflexed, glabrous or slightly arachnoid-hairy, the mid-vein more or less distinctly raised; inner bracts longer than the inner middle, mostly obscurely 3-veined in the distal |, the mid-vein distinctly raised or obscure throughout. Corolla 13-20 mm. Achenes 3-5 mm, compressed and rugulose, or swollen and smooth. An extremely difficult group in need of further detailed study. Although some taxa are easily recognized, there is considerable variation in leaf-dissection, spine-length, peduncle-length, capi­ tulum-diameter, prominence of the mid-veins and the shape of the apex of the involucral bracts. This variation is almost continuous in the centre of the range and intermediates between taxa can be found. The greatest difficulties are encountered in the Alps where hybrids seem to occur not only between members of this group but also with such taxa as 12, 17(a) and 18(b). Plants with scattered multicellular hairs on leaves and stem-wings, thicker, more spiny leaves and appressed, acute, spiny, subequal outer and middle involucral bracts are probably hybrids involving 12; plants with slightly lobed or dentate leaves with both unicellular and multicellular hairs beneath and slender, acute, lax involucral bracts are probably hybrids involving 17(a), while those with rather thin discolorous leaves with unicellular and multicellular hairs beneath and appressed, unequal involucral bracts slightly recurved at apex probably involve 18(b). To some of these hybrids, found in the S.W. Alps, the chromosome numbers 2« = 20, 20+1-3B, 21 and 23+ 0-3В may be referred. The taxa described below, most having glabrous leaves, were selected as the most distinct and plants with other combinations of characters may be suspected to be of hybrid origin. 1 Leaves entire and spinulose-ciliate or dentate with numerous spinose teeth; achenes with ovoid-globose apical prominence

25. defloratus 1 Leaves lobed to pinnatisect; achenes with oblong apical prominence

2 Leaves thin; leaf-lobes and stem-wings with spine not more than 2(-3) mm; pappus 10-13 mm 26. argemone 2 Leaves thick; leaf-lobes and stem-wings with spine not more than 10 mm; pappus 13-16 mm 27. carlinifolius