The Botany of Iceland - 01.12.1912, Síða 193

MARINE ALGALVEGETATION
179
The Fruiting-period of the Species (continued).
Spring Summer Autumn Winter
Chætomorpha tortuosa
C. Melagonium + _L ■ —
Rhizoclonium riparium — _L — —
Spongomorpha vernalis + +
Acrosiphonia albescens + + +
A. incurva + + +
A. hystrix + +
A. flabelliformis —
A. penicilliformis +
Cladophora rupestris _L — _L —
C. hirta — +
C. sericea + + + —
C. giaucescens —
C. gracilis — —
Gomontia polyrrhiza _L _L +
Ostreobium Queketti — — —
Cyanophyceæ.
Pleurocapsa amethystea — — —
Plectonema norvegicum —
Phormidium autumnale —
Spirulina subsalsa — —
Calothrix scopulorum — —
Rivularia atra —
By looking through the above table it is seen that in the case
of a number of species the fructification-period is of long extent.
Some nine species have been found fruiting all the year round,
but I presume thal by future investigations it will be proved that
many more species bear fruit during the whole year. Kjellman
(36) mentions 11 species which bear fruit all the year round in the
Arctic Sea, and Rosenvinge (63) mentions 6 species which fruit
all the year round along the coast of Greenland, and he adds that
probably there are many more.
If we consult the table as to which season of the year is richest
in fruit-bearing species it is easily seen that summer stands highest,
with 64 % of the total number of species; then comes spring with
42 %, and after that autumn with 33 °/o. As the conditions during
winter are so very little known no percentages can be given for
that season.
It is well-known (Kjellman, Rosenvinge, Börgesen) that
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