The Botany of Iceland - 01.12.1942, Blaðsíða 221
THE PTERIDOPHYTA AND SPERMATOPHYTA OF ICELAND
219
found that there was an equal number of female and bisexual specimens; in Seyðis-
fjörður the bisexual plants by far outnumbered the female ones. The length of the
petals was 10—11 mm in bisexual specimens, in female specimens 8 mm, the
rudimentary stamens in female specimens bearing only very small, roundish and
whitish anthers.
Common throughout Iceland, in the lowland as well as the central highland ;
altogether one of the commonest plants also at a higher level.
Life-form: Ch.
In fell-field, Calluna heaths and moors, grass-moors, in low scrub; practically occur-
ring in all kinds of localities with dry soil.
Flor. VI—VII ; fr. mat. VII—VIII.
Max. height: 26 cm ; average : 11 cm.
Geogr. area: N. Am. : Barren Grounds, Gulf of St. Lawrence to Alaska.—Greenl.:
Circumgreenlandic.-—Eur.: E.S.; arctic regions; Alps, Pyrenees, Karpathians, Ural;
Novaya Zemlya, Spitsbergen.—Asia: Siberia, China, Altai.
Cerastium arvense Linn.
Babington, 1871, p. 299.
Recorded by Babington, loc. cit., as found by Steenstrup on Fjallabaksvegur.
Should be excluded from the Icelandic flora.
183. Cerastium caespitosum Gilib., Fl. Lithuan. V (1781) p. 159.
C. vulgare, K. & M., 1770, p. 207.—C. triviale Link, Babington, 1871, p. 299.
—C. vulgatum L., Gronlund, Isl. Fl., 1881, p. 37.—C. vulgare Hartm., Ste-
fánsson, Fl. Isl., ed. 1, 1901, p. 84.—C. caespitosum Gilib., Ibid., ed. 2, 1924,
p. 95,—O. & Gr., 1934, p. 60.
Icon.: Lindman, Svensk Fanerogamflora, 1918, p. 238, fig. 160, 6 (C. caesp.
L. var. alpestre Lindbl.).
Icelandic: Vegarfi. Danish: Almindelig Honsetarm. English: Chickweed, Mouse
Ear.
Very varying. The common form in Iceland is the var. (or subspecies) alpestre
Lindblom in Fries, Summa veg. Scand. I (1846) p. 37.
Following Ascherson & Graebner, Synopsis der mitteleuropáischen Flora
Bd. V. 1 (1918) p. 646 et seq., the Icelandic Cerastium caespitosum should be
placed under C. fontanum Baumg., Enum. stirp. Transs. I (1816) p. 425 (Syn.
C. vulgatum L. var. alpestre Lindblom in Fries, loc. cit.).
According to A. & Gr., loc. cit., it is to be considered a well defined species,
and transitional forms to C. caespitosum do not exist. From the last-named species
it ís distinguished as follows: Plant usually forming rather dense carpets, with
numerous sterile shoots; long- and densely hirsute, usually without glands. Flowering
stems ascending. Leaves ovate to longish, the lowermost attenuated into a stalk,
often acute. Inflorescence few- (3—7-) flowered. Lower bracts mostly herbaceous,
'vith membranous margin. Flowers usually twice as large as in C. caespitosum. Petals
^■5 ^ mm long, onc and a half times as long as the sepals. Capsule large, broad,
^ 3 times as long as the calyx. Seeds large, 0.9—1.1 mm in diameter, with
prominent warts.
Very common throughout Iccland, also in the central highland.
Life-form: Ch.
In meadows, hcaths, scrub, fell-field, on grassy slopes, on Cultivated soil, among
mosses on brooksides.