The Botany of Iceland - 01.12.1942, Side 51

THE TARAXACUM-FLORA OF ICELAND
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has almost the same shape. The latter, however, has much darker heads, more deeply
coloured petioles and mid-nerves and a narrower terminal lobe.—T. obovatifrons has
been cultivated and proved unlike all other cultivated Icelandic Taraxaca. Especially
the first rosette of leaves was very characteristic, with broadly obovate leaves.
It is no doubt spontaneous.
Habitat: Birch-copses, meadows, grassy mountain-slopes, ditches.
Localities: Hallormsstaður, 24.VII.1935, abundant, fr., phot. E.—Siglufjörður,
30.VII.1937, fr., Varmahlíð, 18.VII.1937. N.
Geogr. Distr.: Only found in Iceland.
33. Taraxacum macromerum M.P.Chr. n. sp.
Spec. orig.: Iceland, Siglufjörður, 14.VII.1935, leg. M. P. Christiansen. Plate III,
fig. 33. Plate XXI, fig. 147.
Planta 15—30 cm alta. Folia obscure viridia, sat lucide lutescentia, leviter
undulata, parce araneosa, lingulato-lanceolata, parum profunde 2—4-loba—sub-
integra et valde dentata, petiolis alatis, pallidis, nervo mediano pallido—vel paulo
colorato, fol. exteriorum lobis latis, sat brevibus, acutis, sat reflexis, lobo terminali
longo—perlongo, lingulato-sagittato vel lingulato-hastato, saepe integro, obtuso,
intermediorum lobis + patentibus, sat valde dentatis, lobo terminali mediocri—
longissimo, + late sagittato-hastato, supra lobulos basales saepe late et robuste
dentato.
Involucrum basi ovatum. Squamae exteriores adpressae—erecto-patentes, late
ovatae—lanceolatae, 4—2 X 6—8 mm, subtus obscure virides, + purpurascentes,
haud vel angustissime albido-marginatae, supra virides, ecorniculatae.
Calathium 45—50 mm latum, planum, radians, obscure luteum. Ligulae mar-
ginales c. 3 X 18 mm, planae, subtus stria cano-purpurea notatae, dentibus atro-
purpureis.
Antherae valde polliniferae.
Stigmata virescentia.
Achenium stramineum (laete 162), c. 3.6 mm longum, 1.1—1.2 mm latum, sat
turbinatum, superne minute spinulosum, ceterum laeve, in pyramidem 0.2—0.3 mm
longam, conicam sensim abiens. Rostrum 8—9 mm longum.
T. macromerum seems closely related to T. luteodens (see the latter) and is
recognisable by its dark-green leaves, the often very long, lingulate terminal lobe
and by the large, dark-yellow, radiating heads with plenty of pollen. The species
has fruits of the same shape as the fruits of T. pravicentrum, T. obovatifrons and
nearly allied species.—T. macromerum was cultivated ; the hortal form was coarse
and robust, very different from other Icelandic species. After flowering it had
entire, very large and broad (obovate-lanceolate) leaves with short, but coarse
teeth.
Habitat: Home-fields, ditches, etc.
Localities: Siglufjörður, 14.VII.1935, fr., phot. N.
Geogr. Distr.: Only found in Iceland.
34. Taraxacum luteodens M.P.Chr. n. sp.
Spec. orig.: Iceland, Þrastarlundur, 11.VII. 1937, leg. M. P. Christiansen. Plate
III, fig. 34. Plate XX, fig. 146.
Planta 30—45 mm alta. Folia lutescenti-viridia, fere glabra, longa, sat late
lingulata, 2—3-loba, petiolis angustis—latioribus, pallidis, nervo mediano pallido—
paulo colorato, lobis approximatis, e basi latis, deltoideis, patentibus—leviter reflexis,
acutis, antice rectis—concavis, o—pauci-dentatis, lobo terminali sat magno, ovato—
The Botany oí Iceland. Vol. III. Part III.
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