The Botany of Iceland - 01.12.1942, Síða 26

252
M. P. CHRISTIANSEN
3. Localities of Icelandic Taraxacum-species and description
of new species.
a. Erythrosperma Dahlst. p. p.
Key.
a. Corollas often + tubular—perfectly tubular.
1. T. diversiflorum M.P.Chr.
aa. Corollas normal.
2. T. arrigens M.P.Chr.
1. Taraxacum diversiflorum M.P.Chr. n. sp.
Spec. orig.: Iceland, Vestmannaeyjar, 4.VII.1935, leg. M. P. Christiansen. Plate I,
fig. 1. Plate XI, fig. 117.
Planta humilis, 12—20 cm alta. Folia1 2 laete viridia—canescenti-viridia, sat dense
araneosa, lanceolata, 3—6-loba, petiolis angustis, pallidis—leviter roseis, nervo mediano
pallido vel roseo, lobis sat distantibus, ad basin latis, deltoideis, in apicem angustum,
obtusiusculum—sat acutum, leviter retroversum abeuntibus, antice concavis—sigmoi-
deis, saepe integris, interlobiis angustis parce dentatis, lobo terminali sat parvo, sagit-
tato—hastato, supra lobulos basales + contracto, lobulis basalibus brevibus, patentibus
vel sat retroversis, obtusis—breviter acutis.
Involucrum parvum, laete viride, basi ovato-truncatum. Squamae exteriores ovatae
—ovato-lanceolatae, in apicem angustum, obtusum attenuatae, conspicue corniculatae,
laete virides, + roseo-marginatae, interiores sub apice roseo-corniculatae.
Calathium parvum, 25-—30 mm latum, planum, radians. Ligulae + tubiferae—
fere ubique tubiferae (et calathium valde radians), interdum fere lingulatae, mar-
ginales c. 2.8 X 10 mm, subtus stria cano-purpurea notatae.
Antherae polliniferae.
Stylus et stigmata lutea.
Achenium fulvo- vel violaceo-rubrum (112—113), 3—3.2 mm longum", c. 0.9 mm
latum, superne spinulis erecto-patentibus praeditum, ceterum + laeve, in pyramidem
conico-cylindricam, 0.9—1.0 mm longam sensim abiens. Rostrum 6—7 mm longum.
T. diversiflorum is reminicent of T. laetum Dahlst. as regards the leaves, but is
surely not closely related to this species. It is characteristic by its often perfectly
tubular corollas. In some heads all the corollas are tubular, and this gives the heads
a slender appearance; in others only the inner corollas are tubular, and in others,
again, the heads have all the corollas quite normal.
It is spontaneous.
Habitat: The foot of grassy mountain-slopes, homefields and heaths.
Localities: Vestmannaeyjar, 4.VII.1935 and 28.VI.1937, fr., phot. Hlíðarendi,
2.VII.1937, Múlakot, 2.VII.1937, plentiful, phot. Stórólfshvoll, 9.VII.1937, in
quantity. S.
Geogr. Distr.: Only found in S. Iceland.
2. Taraxacum arrigens M.P.Chr. n. sp.
Spec. orig.: Iceland, Hallormsstaður, 24.VII.1935, leg. M. P. Christiansen. Plate
I, fig. 2. Plate XI, fig. 118.
Planta sat parva, 10—15 cm alta. Folia laete viridia, leviter araneosa, lanceolata,
3—6-loba, petiolis pallidis, nervo mediano pallido— + brunnescenti, lobis ap-
proximatis—sat distantibus, nunc deltoideis, leviter retroversis, nunc sat hamatis,
1 If not otherwise stated the leaves described are the intermediate and outermost
ones.
2 Excluding the pyramid.