The Botany of Iceland - 01.12.1949, Qupperneq 31

THE ELORA OF REYKJANES PENINSULA
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81. Juncus trifidus L., Sp. pl. (1753) 326. var. vaginatus Neilr.
5—59° m-
In dry, windy places very common. Flowering from the end of June till the
end of July. Most common is the form with one flower only. From 34 stems
were xy with one flower, n two-flowcred, 4 three-flowered and 2 four-
flowered. The number of stems per indiv. differs. Average from 6 indiv.
gives 43 stems per individual. One capsule contains in average from n ex.
about 14 seeds. One individual has thus on average about 1000 seeds.
Hafnarfjörður (Solander); Vífilsfell 373—560 m; Skálafell 574 m; W-Plateau
590 m; Brennisteinsfjöll 560 m; Geitafjall 500 m; Sveifluháls 320 m; Vatnshlíð
320 m; Djúpavatn 290 m; Herdísarvík 180 m; Sandfellsheiði 75 m; Cape
Reykjanes 10 m; Háaleiti 35 m; Keilir 379 m; Grindavík 5 m.
82. Juncus triglumis L. Sp. pl. (1753) 328 var. typicus Buchenau.
j—380 m.
In bogs not rare. Fl. 15. VI.—14. VII.
Hafnarfjörður (Solander); Seltjörn 7 m; Snorrastaðatjörn 7 m; Krísuvík 170 m;
Stori Nýibær 145 m; Herdísarvík 5 m; Krokamýri 200 m; Vigðísarháls 210 m;
Fóelluvötn 180 m; Sveifluháls 240 m; (Hengill 380 m).
83. Luzula arcuata (Whlbg.) Swartz (1814) 13.
140—632 m.
Highland element, seldom descending below 250 m. One stem has (average
from 7 samples) about 13—14 flowers. One capsule contains 2—3 seeds; one
stem produces thus about 36 seeds. Fl. from the end of June till the beginning
of August.
W-Plateau 477—590 m; Geitahlíð 280—386 m; Vífilsfcll 370—560 m; Skála-
fell 460—574 m; Bláfjöll, cote 632 m; Geitafjall 500 m; Súlur at Grindavík,
below the top in a rather exposed place, in Alchemilletum alpinae, 140 m;
Brennisteinsfjöll 523 m: fr. 24. VII. 37.
84. Luzula multiflora (Retz.) Lejeune (1811) 169.
10—460 m.
In the heath, copses, in Nardetis common. Fl. Junc and July. One individual
has usually 1 stem only, with 24—25 flowers as an average (from 10 samples).
The capsule contains always 3 seeds only (from 10 samples). Thus one idiv.
porduces about 73 seeds.
Krísuvík (Steenstrup), Hafnarfjörður (Grönlund), Kúadalur (Grönlund), Cape
Reykjanes 10 m; Merkincs 10 m; Porbjörn 40 m; Hvaleyarvatn 40 m; Geita-
hlíð 99 m; Almcnningur 80 m; Svartsengi 79 m; Sandfellsheiði 75 m; Grinda-
vík 70 m; Snókafell 125 m; Hagafell 120 m; Stakkavík 120 m; Seljahlíð 100
m; Búrfell 140 m; Máfahlíð 198; Geitafjall 200 m; Ketill 225 m; Djúpavatn
290 m; Vífilsfell 309 m; Leirdalur 178 m; Vatnshlíð 200 m; W-Plateau 460 m,
etc.
8j. Luzula spicata (L.) DC. (1805) 161.
10—685 m.
Common. One indiv. has about 4 stems (aver. from 7 samples); one stem has
usually about 35 flowers (average from 25 samples); each capsule contains