The Botany of Iceland - 01.12.1912, Síða 188
174
H. JÓNSSON
both Ascophijllum and F. inflatus are sterile, but at that time a few
individuals of F. vesiculosns bear young receptacles. From the middle
of October until December there are no observations to hand from
Revkjavík. The usual course, with regard to these species, appears
to be as follows: In the latter part of the autumn the development
of the sexual organs begins, and is continued tliroughout the winter;
in March the species are found everywhere with ripe sexual organs
and the spores continue their development until the latter part of
the summer.
Kjellman (36, p. 195) records with regard to Ascophiillum no-
dosum in Finmark, that it had numerous receptacles in July and
the first half of August, was sterile in the latter part of August,
and that new receptacles had begun to appear in October. Foslie
(18, p. 64) records witli regard to the same species in East Finmark
that it has abundant receptacles in July and is sterile in August.
In the Færöes (Börgesen, 12, p. 830) Ascophyllum nodosum has
young receptacles in December and fruits during the wliole sunimer.
On the west coast of Sweden tlie sexual organs begin to de-
velop late in August or early in winter (Kylin, 45, p. 106), and by
the beginning of June the receptacles have fallen off.
Fucus inflatus probably behaves in East Finmark in a similar
manner as at Reykjavík. Foslie (18, p. 67) mentions receptacle-
bearing individuals in June—July and the first part of August. At
Spitzbergen it bears fruit during winter and Kjellman (36, p. 204)
found germinating spores in December, January, February and
March.
To Group 2 belong, in addition, prohaf)ly all the Laminariaceœ,
Rhodochorton Rothii, Polysiphonia urceolata, Halosaccion, Gigartina
mamillosa, Odonthalia and probably many more. Petrocelis Hennedyi
belongs also most nearly lo this group; it has been found producing
fruit the whole year, but in spring, suinmer and autumn onlv a
few fruiting crusts are found, while the winter appears to be the
ordinary fruiting period. Chœtopteris ptumosa I include, although
with doubt, in this group.
Group 3. To this belong Desmarestia aculeata, whicli has heen
found fruiting in October, Rhodomela lycopodioides, Delesseria san-
guinea and others.