The Botany of Iceland - 01.12.1942, Blaðsíða 104

102
JOHS. GRONTVED
500 m s. m.), at least in favourably exposed localities. Porsild, 1920, p. 26, calls it
a lowland plant in Greenland.
Life-form: H.
On meagre and dry grassland, mó, in Salix and Betula scrub, heaths; lava-fields;
on herb-slopes and on south-exposed slopes in the central plateau.
Max. height: 20 cm; average: 8 cm.
Geogr. area: N. Am. : From Labrador to Alaska, southward to California, Colorado,
Minnesota, etc.—S.Am.: Patagonia.—Greenl.: W. 60°—69° 15'. E. 60°—71°40\—
Eur.: Fær.; E.S.I.; throughout Eur., except in the southernmost parts.—Asia:
Siberia from 60° N. lat., southward to Asia Minor. Persia, Himalaya. Korea,—-Au-
stralia: New Zealand.
18. Ophioglossum vulgatum Linn., Sp. pl. ed. I (1753) p. 1062.
K. & M., 1770, p. 211.—Babington, 1871, p. 348. O. vulgatum L. var. poly-
phyllum A.Br., Stefánsson, Fl. ísl. ed. 1, 1901, p. 1.—Ibid. ed. 2, 1924, p. 1.—
O. vulgatum L. var. minus Moore, O. & Gr., 1934, p. 5.
Flora Dan. tab. 147.
Icelandic: Naðurtunga. Danish : Slangetunge. English: Adder’s-tongue.
It is recorded in all the older lists, beginning with König & Miiller. The first
specimens in evidence, however, were taken by Thoroddsen 1882 near Bjarnaflag
east of Mývatn, N.
In Iceland only the var. polyphyllum A.Br. is found ; usually two, sometimes three
leaves sprout from the same rhizome. Thoroddsen (1914, p. 322) maintains that
Ophioglossum “grows only near solfataras”. I myself found it growing in abundance
near the hot springs at Hveravellir (D. 12), where also sulphureous vapours rise
from cracks in the rock; in many places sulphur was also deposited at the surface
around the holes. Specimens were growing on soil with a temperature of 37° C at
Fig. 20. Ophioglossum vulgatum L.