The Botany of Iceland - 01.12.1942, Side 63
THE TARAXACUM-FLORA OF ICELAND
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Localities: Múlakot, 3.VII.1937, Húsadalur and Stóriendi ! in Þórsmörk, 8.VII.
1937, Stórólfshvoll !, 9.VII.1937, Breiðabólsstaður !, 9.VII.1937. S.—Hveragerði !,
2.VII.1937, Reykjavík, 9.VII.1935, fr., phot., Þingvellir, 7.VII.1935 and 30.VI.
1937, Hafnarfjörður, 8.VIII.1935, l.VII.1937, Gufunes, 19.VI.1896 (C. H. Osten-
feld), Reykjavík, VI.1876 (Gronlund), 6.VI.1884 (Warming and Holm), Húsafell,
20.VII.1910 (Helgi Jónsson). S.W.—Hreðavatn !, 14.VII.1937. W.—Siglufjörður,
13.VII.1935, Varmahlíð !, 17.VII.1937, Akureyri, 2.VIII.1935 and 22.VII.1937,
Skógar in Fnjóskadalur !, 27.VII.1937, Laugar at Breiðamýri, 27.VII.1937, Sandfell
near Miklavatn, 2.VII.1930 (Thorv. Sorensen). N.—Snæfell near Vatnajökull, 20.
VII.1935 (Johs. Gröntved). E.
Geogr. Distr. : Only found in Iceland, common and plentiful.
Rufescentia.
50. Taraxacum Davidssonii M.P.Chr. n. sp.
Spec. orig.: Iceland, Hestahraun, 3.VIII.1899, leg. Ólafur Davíðsson. Plate IV,
fig. 50. Plate XIV, fig. 128.
Planta alta. Folia laete, + lucide viridia, lutescentia, glabra—parce araneosa,
anguste lanceolata, 3—4-loba, petiolis longis, angustis, pallidis, nervo mediano pallido
—paulo brunnescenti, lobis saepe alternis, distantibus e basi latissimis, brevibus,
deltoideis, patentibus, obtusis—acutiusculis, apice interdum angustis, subulato-acumi-
natis, antice parce sigmoideis—convexis, integris vel inferioribus denticulatis, lobo
terminali brevi, saepe obliquo, triangulari-hastato, mucronato—acutiusculo, integro.
Folia interiora magis dentata.
Involucrum obscure olivaceo-viride. Squamae exteriores erecto-adpressae, 2.5—
4.5 X 10-—12 mm, longae, ovatae—ovato-lanceolatae, subtus obscure olivaceo-virides,
albido-marginatae, leviter rubescentes, supra virides-—glaucescentes, haud vel obtuse
callosae, interiores olivaceo-virides, apice obscuro.
Calathium c. 40 mm latum, perobscure luteum. Ligulae marginales c. 2.8 mm
latae, subtus stria sat obscure purpurea notatae.
Antherae polline carentes.
Stigmata lutea, subtus sat obscura.
Achenium brunneo-ferrugineum, c. 3.6 mm longum, 1.0-—1.2 mm latum, superne
crebre, breviter, sat robuste erecto-spinulosum, ceterum laeve—leviter (interdum
valde) tuberculatum, in pyramidem conico-cylindricam, 0.6—0.7 mm longam sat
abrupte abiens. Rostrum longum, brunnescens.
T. Davidssonii is distinguished by its dark-yellow female heads, broadly ovate,
dark-green, appressed outer bracts, and somewhat reddish fruit with rather coarse
spines above, in which character it differs from the other Icelandic species with
reddish fruits. T. obtusatum Dahlst. seems to be related, but this species has flowers
with plenty of pollen and fruit with acute spines and the pyramid 1 mm long.
It is no doubt spontaneo.us.
Habitat: Home-fields, the banks of rivulets, rock-ledges.
Localities: ísafjörður, 12.VII.1935. N.W.—Hestahraun, 3.VIII.1899 and
7.VIII.1902 (Ólafur Davíðsson), Siglufjörður, 14.VII.1935, Blönduós, 14.VII.1937,
Bakkasel, 21.VII.1937, Víðimýri, 18.VII.1937, Akureyri !, 22.VII.1937, Nes, Skógar
and Vaglaskógur in Fnjóskadalur !, 23.VII.1937, Laugar at Breiðamýri !, 26.VII.
1937, Goðafoss !, 24.VII.1937, Einarstaðir !, 24.VII.1937. N.—Egilsstaðir, 18.VII.
1935, fr., phot., Arnheiðarstaðir, 19.VII.1935, Hallormsstaður, 23.VII.1935. E.
Geogr. Distr.: Only found in Iceland.