The Botany of Iceland - 01.12.1949, Síða 36

34
EMIL HADAC
Kleifarvatn 135 m; Stóri Nýibær, “tún”, 135 m, fl. 21. VI. 37; Vatnavellir
180 m; Þurrá 15 m; Krokamýri 200 m; Hlíðarvatn 3 m; Leirdalur 180 m;
Sveifluháls 220 m; Hengill 384 m.
Caryophyllaceae.
109. Spergula arvensis L., Sp. pl. (1753) 440.
2—225 m.
In open communities on bare soil, scattered.
Vogsós 2 m; Herdísarvík 10 m; Krísuvík 135 m; urá 15 m; Kolviðarhóll
225 m; Hafnarfjörður.
110. Arenaria norvegica Gunn., (1772) 1100.
52—220 m.
Scattered, in open communities. An average individual from Vatnaöldur had
35 flowers; the capsule contains 16—17 seeds (average from 10 samples); thus
one average individual can producc ca. 5.840 seeds. Fl. 15. June—15. July.
Hafnarfjörður; Vatnaöldur 178 m; Klcifarvatn 135 m; Grímshóll 52 m; to
the W from Víti, 220 m.
111. Cerastium alpinum L., Sp. pl. (1733) 438.
2—260 m.
Common. One indiv. has about (8)—21—(58) flowers (average from 19
samples). The capsule contains (19)—34—(15 j) seeds (average from 20
samples). One average individual can thus produce ca. 690 seeds.
Keflavík (Zoega), Krísuvík (Zoega), Hafnarfjörður 10 m, fl. 14. VI. 37;
Seltjörn 8 m; Herdísarvík 2 m; Vífilsfell 373 m; Bláfjöll, cote 620 m;
Sveifluháls 310 m; Djúpavatn 290 m; Ketill 225 m; Herdísarvíkurfjall 70—
180 m; Máfahlíðar 195 m; Skúlatun 155 m; Eldborg 150 m; Súlur 140 m;
Sandfellsheiði 71 m; Cape Reykjanes 20—50 m; Háaleiti 35 m; Central
Highland 35 m; etc.
112. Cerastium caespitosum Gilib. (1781) 159.
1—685 m.
Common. Occasionally zoochore, growing from horse dung. One individual
has ca. 10 stems and 55 capsules (average from 6 samples); the capsule con-
tains ca. (24)—29—(48) seeds (aver. from 10 samples). One average indivi-
dual brings thus about 1590 seeds.
During my field work, I was not avare of two races; by studying the
material I found both ssp. eucaespitosum A. et G. (e. g. Vesturháls), and ssp.
fontanum B a u m g. (e. g. Langahlíð 320 m). The localities cited below
belong to the collective C. caespitosum.
Narfakot 2 m; Látsfjall 85 m; Logberg 140 m; Vífilsfell 654 m; Skálafell
574 m; Bláfjöll, cote 632 m; Hákollur 685 m; Kleifarvatn 140 m; Leirdalur
180 m; Strípshraun 140 m; Búrfell 130 m; Vogavík 1 m; Djúpavatn 290 m;
Geitafjall 245 m; Súlur 140 m; Cape Reykjanes 65 m; Sandfellsheiði 75 m;
Ósar 1 m; Brennisteinsfjöll 560 m; Vatnshlíð 320 m.