The Botany of Iceland - 01.12.1942, Blaðsíða 50

276
M. P. CHRISTIANSEN
31. Taraxacum spiculiforme M.P.Chr. n. sp.
Spec. orig.: Iceland, Laugar at Breiðamýri, 27.VII.1937, leg. M. P. Christian-
sen. Plate III, fig. 31. Plate XXV, fig. 160.
Planta 25—40 cm alta. Folia obscure cano-viridia, fere glabra, longissima, lingu-
lata—anguste lanceolata, parum profunde lobata, petiolis pallidis, nervo mediano
pallido—leviter brunnescenti, lobis c. 2 utrinque, alternis, basin versus latissimis
vel gradatim in interlobia transeuntibus, sensim in apicem acutum, patentem at-
tenuatis, antice concavis, o—paucidentatis, lobo terminali longo, obliquo, lingulato-
hastato, integro.
Scapi folia superantes, pallidi—brunnescentes, glabri.
Involucrum basi sat turbinatum. Squamae exteriores 2—3 mm latae, erecto-
patentes, subtus obscure virides, angustissime albido-marginatae, supra + laete
purpurascentes, interiores apice obscure purpureo-marginato.
Calathium parvum. Ligulae marginales subtus stria cano-violacea notatae.
Antherae polline carentes.
Stigmata virescentia.
Achenium stramineum, c. 4.2 mm longum, c. 1.5 mm latum, superne latissimum
et dense et robuste erecto-spinulosum, ceterum crebre tuberculatum, in pyramidem
late conicam, 0.3—0.4 mm longam, parce spinulosam abiens. Rostrum c. 10 mm
longum.
T. sþiculiforme seems to be closely related to T. þravicentrum, but differs from
this species by its pale petioles and midnerves, female heads and a large, broad fruit
of the same form as the fruit of T. laticonicum, but much more coarsely toothed.
T. longihastatum, with almost the same form of leaves, has very long and narrow
fruits.
Habitat: Ditches.
Localities: Laugar at Breiðamýri, 27.VII.1937, fr., phot. N.
Geogr. Distr.: Only found in Iceland.
32. Taraxacum obovatifrons M.P.Chr. n. sp.
Spec. orig.: Iceland, Hallormsstaður, 24.VII.1935, leg. M. P. Christiansen. Plate
III, fig. 32. Plate XXI, fig. 148.
Planta 15—25 cm alta. Folia laete viridia, lutescentia, fere glabra, lata, obovato-
lanceolata, 3—4-loba, petiolis latis—subangustis, pallidis, nervo mediano supra .+
rubescenti, subtus pallido, lobis brevibus, deltoideis, patentibus, summis interdum
hamatis, breviter acutis—acutis, integris—denticulatis, antice leviter convexis—rectis,
lobo terminali sat magno—magno, cordato-obovato, basi sagittato-hastato, mucronato
—obtuso, marginibus saepe convexis, integris— + denticulatis, interdum dentibus
latis, brevibus, solitariis instructis.
Involucrum olivaceo-viride. Squamae exteriores laxe patentes, 3.0—2.5 X 7—-9
mm, lineari-lanceolatae—lineares, subtus olivaceo-virides, + brunneo-purpurascentes,
supra laete virides et + laete purpureo-marginatae, interiores obscure virides, ecorni-
culatae, apice piceo-purpureo.
Calathium c. 40 mm latum, luteum—laete luteum, convexulum, leviter radians.
Ligulae marginales latae, planae, subtus stria late cano-purpurea notatae.
Antherae polliniferae.
Achenium stramineum, leviter fusco-stramineum (c. 162), c. 3.5—3.7 mm longum,
c. 1.0—1.3 mm latum, superne minute, breviter spinuloso-tuberculatum, ceterum
laeve, in pyramidem conicam, 0.1—0.3 mm longam sensim abiens. Rostrum c. 10 mm
longum.
T. obovatifrons seems to be closely related to T. þravicentrum, the fruit of which