Asperula arvensis, 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 : 13

56. A. arvensis L. , Sp. Pl. 103 (1753) .

Stems (5-)10-55 cm. Leaves (4-)10-25(-35)x 0-6-4 mm, the lowest broadly lanceolate; cauline linear-lanceolate. Flowers 4-merous, equalling or shorter than the bracts. Corolla 5-6-5 mm, more or less salver- form, usually bluish-violet; tube 4-5-5 mm; lobes 0-5-1-7 mm. Filaments 0-2-0-3 mm; anthers 0-7-1 mm. Fruit 2-3 mm in diameter. Fields and waste places. Most of Europe. Al Au BI Bu Co Ga *Ge Gr He Ho Hs Hu It Ju Lu Rm Rs (W, K, E) Sa Si Tu [Cz Da No Su.] (S. W. Asia and N. Africa.)

In most of N. Europe only casual, and in much of C. Europe a naturalized alien; the northern limit of its native range is, however, difficult to establish.

A. orientalis Boiss. & Hohen , in Boiss., Diagn. Pl. Or. Nov. 1(3): 30 (1843) ( A. azurea Jaub. & Spach ), from S.W. Asia, differs chiefly in its corolla 7—12(-14) mm, distinctly exceeding the bract, and its fruits only c. 1-5 mm in diameter. Cultivated for ornament, it has become a casual in S.C. Europe and more rarely elsewhere.