Centaurea calcitrapa, L.

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 : 282-283

148. C. calcitrapa L. , Sp. Pl. 917 (1753).

Stems 20-100 cm, ascending to erect, divaricately branched from the base. Young leaves grey-lanate, becoming greenish and crispate-pubescent, glandular; lower pinnatifid, with lanceolate, acute, remotely serrate lobes, withered at anthesis; upper pinnatifid, with linearlanceolate segments, the uppermost lanceolate or somewhat hastate. Capitula sessile, surrounded by upper leaves. Involucre

6-8 mm in diameter, ovoid-cylindrical; bracts coriaceous, ovate, indistinctly veined, with scarious margin; appendages with slender, patent apical spine 10-18 mm, strongly thickened at base, and usually 1-3 basal spines 3-5 mm. Florets pale purple, glandular, equal. Achenes c. 3 mm; pappus absent. 2л = 20. Waste places and disturbed ground. S. & S.C. Europe; naturalized elsewhere in W. & C. Europe, but less widely than formerly. Al BI Bu Co Cr Cz Ga Gr He Hs Hu It Ju Lu Rm Rs (W, K) Sa Si [Au Be Br Ge Ho].

C. torreana Ten., Ind. Sem. Horti Neap. 1829: 15 (1830), described from S.E. Italy (Mte. Gargano ), is said to be like 148 but has the stems erect with erect branches and the appendages with more slender spines; further investigation is required. Plants of hybrid origin between 148 and 153 (referred to as C. asperocalcitrapa Gren. & Godron , C. calcitrapaspera Gren. & Godron , C. arrectispina Bertol. and C. calcitrapoides auct., non L.) occur commonly where the species grow together.