The Botany of Iceland - 01.12.1942, Blaðsíða 105
THE PTERIDOPHYTA AND SPERMATOPPIYTA OF ICELAND
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a depth of 15 cm. In 1883 Thoroddsen took specimens at Gunnuhver near Krísuvík,
S.W., on soil with a temperature of 27° C. See fig. 20.
Life-form: G. (Rhizome Geophyte).
Max. height: 8 cm ; average : 5 cm.
Geogr. area: Am. : Quebec to Alaska and southward to Washington, Texas and
Florida.—Eur.: E.S.I.; northern and central Europe.—Northern Asia, Asia Minor,
Syria ; Japan.—Afr. : Madeira.
Polypodiaceae.
Asplenium fontanum Presl.
This plant is recorded by K. & M., 1770, p. 211 (as Polyþodium fontanum).
Baring-Gould, 1863, p. 437, names a locality for it (Þingvellir). Cp. also Babington,
1871, p. 348.
It is most unlikely that this south European and Asiatic species should really
have been found in Iceland.
Asplenium septentrionale Hoffm.
Recorded by K. & M., 1770, p. 211 (as Acrostichum septentr.). Baring-Gould,
1863, p. 437, gives the locality Laugardalur; cp. also Babington, 1871, p. 348. In
H.H. there are no specimens from Iceland, and there may be doubt as to its having
really been found there.
Asplenium Trichomanes Linn.
Recorded by Vahl, 1840, p. 375, and by Morch from Búðahraun on Snæfellsnes,
W. (Cp. Babington, 1871, p. 348).—Gronlund has entered it in his Flora 1881,
p. 140.—H. Jónsson (1899, p. 184) searched in vain for it in the locality named ;
no specimens are in evidence, and it may after all be safe to exclude it from the
Icelandic flora.
19. Athyrium alpestre (Hoppe) Rylands, in Moore, Ferns, Gr. Brit.
Nat. Pr. I (1857) t. 7.
Polypodium alpestre Hoppe, Babington, 1871, p. 347.—P. rháticum L., Gron-
lund, Isl. Fl., 1881, p. 140.—A. alpestre (Hoppe) Ryl., Stefánsson, Fl. ísl.
ed. 1, 1901, p. 6.—Ibid. ed. 2, 1924, p. 6,—C.H.O., Fl. arct., 1902, p. 4,—
O. & Gr., 1934, p. 8.
Flora Dan. tab. 2607.
Icelandic : Þúsundblaðarós. Danish : Bjerg-Engelsod.
Rather frequent in N.W., and in the country on the western side of Eyjafjörður,
otherwise rare, see fig. 21.
A specimen from Húsavík, E., leg. H.J., 1894, corresponds rather well to the
var. americanum Butt. (cp. M. P. Porsild, 1930, p. 9). This variety differs from the
main form as follows (Rhodora, vol. 19, 1917, p. 103) :
“omnibus frondium segmentis iisdem formae typicae angustioribus, inter se plus
distantibus ultimis linearibus, soris minutis (0.5—0.7 mm latis) rotundis sub-
marginalibus, soris singulis dente marginali pinnulae everto tectis, velo nullo”.
According to Hegi (111. Fl. Mitt. Eur. I, p. 34) this species prefers colder localities,
northward exposed slopes, where the snow-cover lasts long.