Fróðskaparrit - 01.01.2001, Síða 90

94
SEAWEEDS OF THE FAROEISLANDS
AN ANNOTATED CHECKLIST
tween hollow and solid stiped Laminaria
plants in the North Atlantic with and with-
out mucilage ducts (Chapman, 1974; 1975;
Liining et al., 1978; Bolton et al., 1983).
This suggests that all the plants are closely
related or may belong to the same species,
for which the epithet L. saccharina has pri-
ority. This was challenged by Egan and
Yarish (1990) who argued that L. longi-
cruris has a distinctive morphology with a
characteristic swelling of the upper part of
the stipe separating it from L. saccharina.
Non digitate Laminaria plants with hol-
low stipes have also been observed in shel-
tered localities in southwestem Scotland
(Parke, 1948), the Shetland Isles (Kain,
1976) and in eastern Iceland (Sjotun and
Gunnarsson, 1995). In these localities no
extemal morphological features were
found that distinguished the hollow stiped
plants from the solid stiped L. saccharina
growing amongst them. Therefore, all
plants were referred to L. saccharina by the
respective authors.
The Faroese plants agree with L. longi-
cruris in respect to stipe morphology, how-
ever, as the taxomomic situation in this
complex is still unclear, the name L.
faeroensis is retained in the present paper
pending further studies.
Small epi- and endophytes associated
with larger algae were commonly recorded;
brown algae referable to genera as Chil-
ionema, Myrionema, Phaeostroma and
Strehlonema were difficult to identify. It is
likely that some represent microthalli of
larger brown algae. An interesting continu-
ation for future research would be studies
that involve detailed observation of such
plants in culture supported by molecular
work to assist possible identification.
The identification of Ceramium species
was also a challenge due to the variation
within species as reflected by the large
number of subspecies (cf. Petersen, 1911).
Ceramium pallidum, C. rubrum and C. se-
cundatum were identifieđ with reservation;
characters used were general morphology,
number of segments between primary
branching points, number of periaxial cells
and only little attention to the development
of cortex. The status of C. atlanticum, C.
boergesenii needs confirmation and the
same concems the C. diaphanum recorded
by Irvine (1982). To obtain a better under-
standing of species complexes in this
genus, culture studies with crossing exper-
iments and molecular investigation are re-
quired.
The Cyanophycean flora of the Faroes
needs further studies, in the present study
18 species were identified. Borgesen
(1902) recorded 14 species of
Cyanophyceae of which all except 3, i.e.
Calothrix aeruginea (Kiitz.) Thur. ex Bor-
net & Flahault, Chlorogloea tuberculosa
(Hansg.) Wille and Schizothrix tenerrima
(Gomont) Drouet (as Microcoleus ten-
errimus Gomont), were found in the pre-
sent study. Irvine (1982) recorded 9 species
of Cyanophyceae. But as he applied the
classification system of Drouet and Daily
(Drouetand Daily, 1956; Drouet, 1968), his
records can not be directly compared with
ours. Holt (1975, unpublished report)
recorded a few species not recorded by oth-
ers. We suppose that detailed investigations
including culture studies may confirm