The Botany of Iceland - 01.12.1914, Side 110

294
THORODDSEN
The snow-eovei'ings in the lowlands generally melt away in April
and the period of growth begins in May. But the time for the ap-
pearance of the plants differs considerably throughout the extent of
the island, not only according to position and height above sea-
level, but also on aecount of the conditions of weather in different
years.
In south-west Iceland, in the neighbourhood of Reykjavík, in
somewhat favourable years a few species flower at the end of April,
e. g. Saxifraga oppositifolia and Arabis petrœa, but in the beginning
of May a great many plants are in bloom, e. g. Salix herbacea, Al-
chimilla alpina, A. vulgaris, Draba incana and Silene acaulis, some-
what later and until the middle of the month Caltha palustris, Car-
clamine pratensis, Armeria maritima, Rumex acetosa, Oxgria diggna
and at the end of the month Rannnculus acer, Taraxacum vulgare,
Cerastium alpinum, C. vulgare, Thalictrum alpinnm, Arctostaphglus
uva ursi, Pinguicula vnlgaris, Betula nana and others. The common
flowering period begins in June; and June and July are the months
richest in flowers. For the rest, the flowering period is highly de-
pendent on the weather; it may be delayed in colder years, espe-
cially in ice-years, l)ut on the other hand, during prolonged periods
of thaw in winter some flowers may open in February and March.
On the northernmost points of land and on the plateau the time for
flowering is naturally somewhat later.1
The number. of plant-species found in Iceland cannot yet be
stated with any certainty, but later in this work the lists and col-
lections will be critically investigated and new species added to the
list.2 The number of species of known phanerogams and vascular
1 For observations regarding the tirae of flowering in East Iceland in 1893
and 1894 see Helgi Jónsson: Vinter-og Vaar-Ekskursioner i 0st-lsland (Botanisk
Tidsskrift, 1895, pp. 274—275 and 292—294), and in the neighbourhood of Reykja-
vík in 1873—1875 see Th. Thoroddsen’s notes in Grönlund’s Karakteristik af
Plantevæxten paa Island, pp. 17—18. Moreover, there are some notes on the sub-
ject which have not as yet been published; hut they make no difference as regards
the general sketch of the spring-flowering given here.
■ The chief floristic works on Iceland are the following: — St. Stefánsson:
Flóra Islands, Köbenhavn, 1901. W. Lauder Lindsay: Flora of Iceland. (New
Philosophical Journal, New Series, Edinburgh, July, 1861; 40 pages). C. C. Babington:
A Bevision of the Flora of Iceland. (The Journal of the Linnean Society, Vol. XI,
London, 1871, pp. 282—348). Chl'. Grönlund: Bidrag til Oplysning om Islands
Flora. Höjere Kryptogamer og Fanerogamer. (Botanisk Tidsskrift, 2. Række, IV,
1874, pp. 36—85). Chr. Grönlu pd: Islands Flora. Köbenhavn, 1881. Chr. Grön-
lund: Afsluttende Bidrag til Oplysning om Islands Flora. (Bot. Tldsskr., XIV, 1885,
pp. 159—217). H. F. G. Strömfelt: Islands kárlváxter. (Öfversikt af Kgl. Vetensk.