The Botany of Iceland - 01.12.1942, Blaðsíða 64

290
M. P. CHRISTIANSEN
51. Taraxacum hamidens M.P.Chr. n sp.
Spec. orig.: Iceland, Reykjahlíð, 25.VII.1937, leg. M. P. Christiansen. Plate IV,
fig. 51. Plate XVII, fig. 136.
Planta mediocris. Folia laete viridia, lutescentia, parce araneosa, lanceolata, pro-
funde lobata, petiolis sat latis, pallidis, nervo mediano pallido, lobis fol. interiorum
distantibus, deltoideis—linearibus, hamatis, acuminatis—subulato-attenuatis, margine
superiore saepe longe subulato-dentato vel profunde laciniato, inferiore parce
subulato-dentato, interlobiis angustis, sat longis, integris vel parce dentatis, lobo
terminali brevi, sagittato-hastato, + acute lingulato-protracto, lobulis basalibus acutis,
supra lobulos basales margine rotundato et uni-dentato. Folia exteriora plantae
cultae anguste lingulato-lanceolata, regulariter lobata, lobis sat approximatis, del-
toideis, acutis, patentibus.
Squamae exteriores sat recurvatae, lanceolatae—lineares, 1.0—2.5 X 10 mm,
sensim attenuatae, subtus dilute olivaceo-virides, late albido- vel claro-marginatae,
supra glaucescentes, + roseo-coloratae, interiores apice + obscurae.
Calathium parvum, c. 30 mm latum, croceum, densum. Ligulae marginales subtus
stria cano-purpurea notatae.
Antherae polline carentes (plantae cultae polliniferae).
Stigmata luteo-virescentia.
Achenium dilute rubrum (obscure 103 D), brunneo-ferrugineum, c. 3.6 mm
longum, c. 1 mm latum, sat fusiforme, supeme dense, minute spinulosum, ceterum
laeve, in pyramidem late conicam, c. 0.5 mm longam sensim abiens. Rostrum c.
7 mm longum.
T. hamidens has leaves with narrow, hamate and acute lobes, dark-yellow, female
heads and short, reddish, finely spinose fruits with a broad and short, conic pyramid.
It seems to be closely related to T. Davidssonii and nearly allied species.—The
cultivated plants have small, narrow, lingulate-lanceolate, regularly lobed leaves with
densely placed, deltoid, patent and acute lobes.
It is spontaneous.
Habitat: Home-fields, lava-fields, ditches, etc.
Localities: Blönduós !, 14.VII.1937, Skútustaðir, 28.VII.1935, Vaglaskógur in
Fnjóskadalur, 31.VII. 1935, Reykjahlið at Mývatn, 25.VII.1937, Laugar at Breiða-
mýri, 26.VII.1937, Siglufjörður, 14.VII.1935, fr., phot. N.—Egilsstaðir, 18.VII.
1935, Hallormsstaður, (on mountain slope), 23.VII.1935. E.
Geogr. Distr.: Only found in Iceland.
52. Taraxacum isolobum M.P.Chr. n. sp.
Spec. orig.: Iceland, Siglufjörður, 14.VII.1935, leg. M. P. Christiansen. Plate IV,
fig. 52. Plate XVIII, fig. 139.
Planta sat parva. Folia laete viridia, subglabra, lanceolata, regulariter 3—4-loba,
petiolis pallidis, nervo mediano pallido—paulo colorato, lobis sat distantibus, anguste
deltoideis—linearibus, + reflexis, acutis, integris vel inferioribus parce dentatis,
interlobiis sat longis, sat latis, integris, lobo terminali brevi, triangulari—sagittato,
marginibus fere rectis, integris, lobulis basalibus acutis.
Scapi folia persuperantes, pallidi—brunnescentes, parce araneosi.
Squamae exteriores adpressae, dilute virides, claro- vel rubro-marginatae,
ecorniculatae.
Calathium c. 35 mm latum, obscure luteum. Ligulae marginales c. 12 mm longae,
c. 2.5 mm latae, subtus stria dilute cano-violacea notatae.
Antherae polline carentes.
Stylus luteus. Stigmata virescentia.