The Botany of Iceland - 01.12.1942, Page 102

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M. P. CHRISTIANSEN
Calathium c. 45 mm latum, obscure luteum, irregulares, densum. Ligulae sat
tortae, marginales sat angustae, breves, subtus stria laete luteo-purpurea notatae.
Antherae valde polliniferae.
Stylus et stigmata virescentia—atro-virescentia.
Achenium dilute brunneum vel olivaceo-brunneum (162—154), 3.9 mm longum,
c. 1.2 mm latum, superne dense, longissime, robuste erecto- vel patenti-spinulosum,
ceterum tuberculatum, basi laeve, in pyramidem cylindricam, 0.7—0.8 mm longam,
inferne saepe spinulosam abrupte abiens. Rostrum c. 8 mm longum.
T. hoplites has densely lobed and strongly dentate leaves, tousled heads and
large, coarsely spinous fruits. By the shape of some of its leaves the species recalls
T. islandicum, T. acromaurum and T. subhoplites. The former differs by small,
finely spinose fruits, the latter has long, fusiform fruits and -f- purple-coloured
petioles and midnerves. T. acromaurum has red (at first citron-yellow) fruits. The
species is perhaps a gigas-form of?.
Habitat: Home-fields, lava-fields, rock-ledges, etc.
Localities: Húsadalur and Stóriendi in Þórsmörk, 8.VII.1937, Bleiksárgljúfur,
4.VII.1937, Múlakot !, 3.VII.1937, Stórólfshvoll !, 9.VII.1937, Breiðabólsstaður !,
9.VII.1937, Vestmannaeyjar, 5.VII.1935, fr. S.-—Hveragerði !, 2.VII.1937, Þrastar-
lunður !, 11.VII.1937, Laugarvatn !, 11.VII.1937, Þingvellir, 30.VI.1937, Hafnar-
fjörður, l.VII.1937, phot., Reykjavík, 9.VII.1935, 29.VI.1937, near Árbær, 2.VII.
1936 (Omang), Reykir at Álafoss !, 29.VI.1937. S.W.—Akranes !, 13.VII.1937. W.
—Akureyri !, 22.VII.1937, plentiful, Hof in Hörgárdalur, 17.VII.1898 (Ólafur
Daviðsson). N.
Geogr. Distr. : Only found in Iceland.
102. Taraxacum islandicum Dahlst. ined.
M.P.Chr.: Plate IX, fig. 102. Plate XXXIX, fig. 202.
Planta altitudine mediocris. Folia dilute viridia, glaucescentia, lanceolata, petiolis
angustis, roseo-purpureis, nervo mediano pallido—paulo colorato, lobis approximatis
4—6 utrinque, nunc sat longis, deltoideis, patentibus vel leviter reflexis, integris vel
parce dentatis, nunc a basi latis et subulato-dentatis, in apicem + abrupte lineari-
lanceolatum, acutum, reflexo-patentem vel sat porrigentem abeuntibus, lobo terminali
saepe parvo, triangulari-hastato, acuto, saepe integro.
Involucrum ovatum, c. 11 X 17 mm, laete viride. Squamae exteriores + ad-
pressae—incurvo-patentes, 6—3 X 13—14 mm, ovatae—ovato-lanceolatae, subtus +
brunnescenti-virides, supra laete virides, + rubescentes, denique ubique rubescenti-
purpureae.
Calathium 40—50 mm latum, sat convexum, densum vel leviter radians, sat
obscure luteum. Ligulae marginales 13—18 mm longae, 3 mm latae, planae, subtus
stria cana—cano-violacea notatae.
Antherae polliniferae.
Stylus et stigmata virescentia—atro-virescentia.
Achenium dilute brunneum vel olivaceo-brunneum (162—154), 2.8—3.2 mm
longum, c. 1 mm latum, superne erecto- vel patenti-spinulosum, ceterum tuberculatum
—laeve, in pyramidem c. 0.6 mm longam, cylindricam abiens.
T. islandicum seems to be closely related to T. hoplites and T. acromaurum. The
former differs by large, coarsely spinous fruits; the latter has red fruits.
Habitat: Home-fields, birch-copses, grassy spots in lava-fields.
Localities: Stóriendi ! in Þórsmörk, 8.VII.1937, Múlakot, 5.VII.1937, Stórólfs-
hvoll !, 9.VII.1937, Breiðabólsstaður !, 9.VII.1937, Vestmannaeyjar, 5.VII.1935. S.
—Hveragerði !, 2.VII.1937, Laugarvatn !, 5.VIII.1935, Þingvellir !, 7.VII.1935,
30.VI.1937, Hafnarfjörður !, 6.VII.1935, l.VII.1937, Reykjavík 9.VII.1935, Laxnes,