The Botany of Iceland - 01.12.1949, Síða 34

32
EMIL HADAC
Betulaceae.
97. Betula nana L., Sp. pl. (1753) 983.
30—150 m.
Very rare. Krísuvíkurhraun (Krísuvíkurbjarg—foot of the W-Plateau). Lewis
had found this species in a peat bog near Hafnarfjörður. Krísuvík (Hooker),
Krísuvíkurhraun 30 m, fl. 28. VI. 37; Selalda 100 m; fl. 25. VI. 36; SW
slope of the W-Plateau 150 m.
98. Betula tortuosa Led. (B. pubescens Ehrh. (1791) 98).
40—150 m.
Frequent in the lowland. Devastated by man and his sheep. Seldom higher than
2 m.
Southern slope of the Central Highland 100—150 m; Búrfell 143 m; Húsa-
fell 135 m, fl. and germinating 28. VII. 36; Kaldársel 100 m, germinating;
Sveifluháls 100 m; Seljahlíð 100 m; Almenningur 105 m; Herdísarvík 105 m;
Geitahlíð 110 m; Snókafell 125 m; Hvaleyarvatn 40 m; Hólmshraun 120 m;
Vogsósar 70 m; Strípshraun 140 m; germinating 22. VII. 37; Gullkistugjá 120 m.
Urticaceae.
99. Urtica urens L., Sp. pl. (1753) 984.
2 m.
Near settlements. Introduced.
Grindavík: Garðhúsið (Bjarni Sæmundsson), Hvalsncs (Thoroddsen), Hvaleyri
2 m, 28. VII. 37.
Polygonaceae.
100. Koenigia islandica L., Mant. (1767) 35.
i.j—310 m.
Scattered, in open communities only.
Hafnarfjörður (Grönlund), Kleifarvatn 135 m, fl. 14. VII. 37; Vatnavellir
191 m, fl. 28. VII. 37; Þurrá 15 m; Leirdalur 180 m; Logberg 145 m; Húsmúli
310 m; fl. 6. VIII. 37.
xor. Oxyria digyna (L.) Hill. (1769) 158.
35—685 m.
Common. One indiv. has usually 3—4 stems with ca. 400 seeds.
Arnarfell 123 m; Vífilsfell 654 m; Bláfjöll, cote 620 m; Hákollur 685 m;
Ketill 240 m; Máfahlíðar 195 m; Hagafell 120 m; Háaleiti 35 m; Krísuvík
173 m; Grímshóll 52 m; Brekka 42 m; fl. 16. VI. 37, and germinating.
102. Polygonum aviculare L. Sp. pl. (1753) 362.
1—140 m.
Scattered. Endozoochorous. Often growing from horse dung. Seldom oc-
curring on the sea shore.
Grindavík (Ingólfur Davíðsson), Vogavík, on the sea shore, i m; Kleifarvatn,