The Botany of Iceland - 01.12.1942, Page 364

362
JOHS. GRONTVED
Centaurea Cyanus Linn.
Babington, 1871, p. 314.—Stefánsson, Fl. ísl., ed. 1, 1901, p. 191.—Ibid., ed. 2,
1924, p. 217,—O. & Gr., 1934, p. 138.
Accidentally introduced weed in corn-fields and at farmsteads. Found in some
few places: Hnausar at Húnavatnsflói, and Krossastaðir in Þelamörk, N. ; Hallorms-
staður, E.; Skaptahraun, Hlíðarendakot, and Landbrot, S.
Chrysanthemum Leucanthemum Linn.
Found in one place in N.: Laugar in Reykjadalur (I.D., 1933), and at Grindavík,
S., in a cultivated field (I.D.).
Accidentally introduced. In the Færoes also accidentally introduced in a few
places.
385. Cirsium arvense (L.) Scop., Flor. Cam. ed. 2, II (1772) p. 126.
Serratula arvensis, König & Miiller, 1770, p. 209.—Carduus arvensis Curt.,
Babington, 1871, p. 314.—Cirsium arvense Scop., Gronlund, Isl. Fl., 1881,
p. 78.—Stefánsson, Fl. ísl., ed. 1, 1901, p. 193.—Ibid., ed. 2, 1924, p. 219.—
O. & Gr., 1934, p. 137.
Flor. Dan. tab. 644.
Icelandic: Þistill. Danish: Ager-Tidsel. English : Field Thistle, Creeping Thistle.
Evidently at first accidentally introduced, but seems to have become naturalized;
found here and there in the lowland. See fig. 170.
Life-form: G. (Root Geophyte).
In home-fields, in cultivated soil, around farmsteads and towns.
Flor. VIII; fr. mat. (?).
Max. height: 45 cm; average : 32 cm.
Fig. 170. Cirsium arvense (L.) Scop.