The Botany of Iceland - 01.12.1914, Qupperneq 141

PHYSICAL GEOGRAPHY
325
water-saturated tracts, where the ground is becorning drier, are easy
transitions to other plant-formations, such as grassland, heather-
moor, etc.
Rocky flats. Of all plant-formations, the rocky-flat-formation
occupies the largest area in Ieeland, and is the one which characteri-
zes bjr far the greatest part of the island. In favourably situated loca-
lities nearest tlie coast it passes into a “herb-flat” (Urtemark) with
Fig. 29. Lake near Armuli. with Carex rostrata.
(Phot. A. Hesselbo.)
a dense vegetation of ditferent plants, and with some mosses and
lichens; but usually the plants are too scattered to have anjr influ-
ence wortli mentioning upon the appearance of the landscape. The
vegetation of the rocky flat, which includes a great proportion of
all the plant-species of the island, may be divided into many sec-
tions according to soil-conditions. On climbing higher up on the
plateau we find that species and individuals become fewer in num-
her and more scattered in growth, and as already stated, in the
highest parts of the plateau only a few stunted, widely separated
plants occur. On rocky flats situated at high levels mosses play
an important part, especially Grimmia hypnoides, which gradually
torms soil for higher plants; now and then some fruticose lichens
aie found intermixed with the mosses, and in many places on the