Download The marine flora of the Cap Blanc peninsula: its distribution and

Botanical Journal of the Linnean Society, 75: 99-118.With 4 figures
July 1977
The marine flora of the Cap Blanc peninsula:
its distribution and affinities
G. W. LAWSON
School o f Plant Biology, University College of North Wales, Bangor
AND
D. M. JOHN
Department of Botany, University o f Ghana, Legon, Ghana
Accepted for publication November 1 9 7 6
The shores of the Cap Blanc peninsula, along which runs the border between Mauritania and
Western Sahara (former Spanish Sahara), were studied in November 1975. Littoral zonation is
described and an annotated list is presented of the 188 species of algae now known from
Mauritania and Western Sahara together with a further 23 species identified only t o genus. In
this present study 88 species of algae (excluding Cyanophyceae) were determined resulting in
an increase of 67% and 37% respectively for the previously known marine floras of Western
Sahara and Mauritania. Of 97 marine algae known from specific localities on the Cap Blanc
peninsula, only 21 are common to both its eastern and western sides. Several tropical species
reach their northern limit on the eastern side of the peninsula and many warm-temperate
species reach their southernmost limit on the western side. Thus the Cap Blanc peninsula
appears to represent a boundary between the warm temperate seaweed flora of North West
Africa and the subtropical transition flora of Mauritania and Shegal to the south.
KEY WORDS :-marine algae-distribution.
CONTENTS
Introduction
. . . . . . . . . . . .
Physical features of the environment
. . . .
Patterns of littoral zonation
. . . . . .
Baie de I’Etiole (site 1) . . . . . .
Pointe de 1’Etiole to Pointe des Maures (site 2)
Lagoon (site 3)
. . . . . . . .
Nouadhibou (site 4)
. . . . . .
Cansado (site 5)
. . . . . . . .
Cap Blanc-east side (site 6)
. . . .
Cap Blanc-west side (site 7)
. . . .
La Giierra (site 8)
. . . . . . .
General features of zonation
. . . .
Discussion
. . . . . . . . . . . .
Annotated species list
. . . . . . . .
Acknowledgements
. . . . . . . . . .
References
. . . . . . . . . . . .
99
.
.
.
.
.
.
.
.
.
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
. .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
. . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
. . . . .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
100
101
103
103
104
105
105
105
106
106
107
107
108
110
116
116
100
G. W. LAWSON AND D. M. JOHN
INTRODUCTION
The Cap Blanc peninsula, on the coast of West Africa, occupies a position of
some considerable interest for marine biogeography. To the north, stretching
for over 1000 km and lying partly within and partly outside the tropics, is the
inhospitable coastline of former Spanish Sahara. Morocco and Mauritania took
over the administration of this Spanish colony in 1976 and since then the
country has been known as Western Sahara. Marine algal records from this
country are very few and an assessment of the exact number of species is
complicated by the fact that the northern boundary of Western Sahara has
been subject to a number of political changes in recent times. Since most of
what collecting has been done has taken place in the northern region, records
for seaweeds from ‘Spanish Sahara’ and ‘Rio de Oro’ in the literature, where no
specific localities are given, have to be assessed according to the date of
publication. In the brief account by Primo (1953) it is clear that the algal
vegetation of the northern region around Cape Juby (which became part of
Morocco in 1958) bears a strong resemblance to the coast of North-west Africa
and South-west Europe in having large kelp beds of Saccorhiza polyschides and
Laminaria ochroleuca along with fucoids including Fucus spiralis and Bifurcaria
bifurcata. Such plants are characteristic of the colder northern waters but it
should be noted that Primo also records some warmer water species, for
example, Sargnssum vulgare. The most southerly point he studied was
apparently around Dakhla (formerlv Villa Cisneros) which lies just outside the
tropics. He reported a single instance of a holdfast of Saccorhiza polyschides
found fixed to a rock so it is clear that the bulk of the Laminariaceae drop out
somewhere between Cape Juby and Dakhla. The Western Saharan side of the
Cap Blanc peninsula apparently has not been the subject of earlier investigations although Hariot’s Mauritanian records (Hariot, 1911) are from the Baie de
1’Ouest which straddles the border between the two countries. Feldmann
(1951) also records Ecklonia muratii from ‘L’Aguerguer’ which is about 50 km
north of the tip of Cap Blanc and hence in Western Sahara.
To the south of the Cap Blanc peninsula, as Sourie (1954a) has pointed out,
the coastline consists almost entirely of beaches and dunes and is largely
unsuitable for algal attachment for about 750 km until the village of Yof is
reached at the north-western extremity of the Cap Vert peninsula. The marine
flora of the Cap Vert peninsula is one of the better-known in West Africa
following the work of Bodard (1966; 1968), Dangeard (1952), Sourie (1954a,
1954b), and Trochain (1940). It appears to represent a transition zone between
the northern warm temperate province and the tropical Gulf of Guinea region
where some species such as Ecklonia muratii, Plocamium raplzelisianum and
Corallina mediterranea reach their southern limit. Where many of the Gulf of
Guinea species reach their northern limit is not always clear. One of the objects
of the present survey was to find out the extent t o which the tropical element
reaches northern Mauritania and the degree to which the Cap Blanc peninsula
can also be regarded as a transition zone.
The Cap Blanc peninsula partly encloses on its eastern side the Baie du
LCvrier, one of the largest bays along the west coast of Africa. This shallow bay
is protected to some extent from cold upwelling water and from heavy
wave-action by the peninsula. Sea surface temperatures in the bay are therefore
MARINE FLORA O F THE CAP BLANC PENINSULA
101
always higher than those on the Atlantic side of the peninsula (see Fig. 2). It is
clear that conditions for marine life are somewhat different on the two sides of
the peninsula (see below) and it is to be expected that these will be reflected in
floristic differences.
A total of 115 species of marine algae has been recorded in papers dealing
with Mauritania. The great majority are from Cap Blanc itself and most of these
are from the eastern side, although Hariot (1911) records 19 species from 'Baie
de l'Ouest' which is on the western side of the peninsula. Dangeard's records
(Dangeard, 1952) are apparently from the eastern side and Sourie's (Sourie,
1954a) are from the east and also the southern tip of Cap Blanc. Only a few
algae are reported from areas outside the peninsula, such as at Cap St Anne
(Hariot, 1911).
PHYSICAL FEATURES OF THE ENVIRONMENT
The Cap Blanc peninsula, which runs roughly north-northeast to southsouthwest for about 60 km (Fig. l ) , terminates in a plateau edged by tall and
precipitous cliffs of ill-consolidated quaternary marine deposits. P.ock falls have
taken place where the sea has undercut these friable sandstone cliffs and the
resulting breaks often afford the only access to the littoral zone for large
stretches of shoreline. These high cliffs give way northward to sandy beaches
and low rocky outcrops which are interspersed between areas of low cliff. On
the eastern side of the peninsula the littoral rocks extend intermittently for
almost half of its length reaching as far as the Baie de 1'Etiole. This bay consists
of a shallow basin opening to the sea by a tidal creek. In the vicinity of the Raie
de l'Etiole, and particularly to the north of it, are a number of very shallow
lagoons in contact with the sea only at high waters of spring tides.
Cap Blanc lies within the subtropical arid zone having a very low rainfall and
air humidity, and large daily and yearly fluctuations in air temperature. The
rainfall is insignificant and only 10 days per annum on average have 0.1 mm or
more. Relative humidity at noon for any month of the year never averages
more than 65%. The highest mean daily air temperatures are to be found in
October (30"C), and the lowest in December and January (25°C) when the
dry, north-easterly Harmattan wind blows for much of the time from the
desert. During the early part of the year this wind gradually veers to the west so
that by July it blows predominantly from the north-west and during the same
period the relative humidity at midday rises from about 55% in January to 65%
in July. Towards the end of the year the wind direction becomes more
northerly and the relative humidity begins once more to decline. There are
considerable daily fluctuations in air temperature with the average daily range
for the year being from 10" t o 15" C.
This part of the West African coast is bathed by the cold Canary current
whose general set is south-westward, i.e., almost parallel t o the coast. The
seasonal change in the temperature of the surface water in the vicinity of Cap
Blanc (Fig. 2) shows that the highest temperatures are attained between July
and October (>21" C). A rapid fall in sea temperature takes place in November
with the minimum seasonal temperature being found from November to about
May (1 6" to 19"C). The low sea temperatures are due to the combined effect
of the Canary current and to the upwelling of colder under-surface water which
G. W. LAWSON AND D. M. JOHN
102
lorn
8
20040
17‘00
1
1P50
1
Figure 1. Map of th e Cap Blanc peninsula showing t h e eight sites visited. A and B are stations at
which sea water temperature was measured (see Fig. 2). Insert indicates the position of the Cap
Blanc peninsula in relation to th e rest of t h e North West African coast. Sites: 1, Baie d e 1’Etiole;
2, Pointe de 1’Etiole t o Pointe des Maures; 3, Lagoon; 4,Nouadhibou; 5 , Cansado; 6, Cap
Blanc-east side; 7, Cap Blanc-west side; 8, La Giierra.
occurs along the West African coast and is, in fact, most marked near Cap
Blanc.
The hydrological conditions on the eastern and western side of the Cap
Blanc peninsula are dissimilar. The shallow Baie du LCvrier on the eastern side
of the peninsula is less than 10 m deep over most of its area and never more
than 20 m. In this bay the seg surface temperatures are always about a degree
or two higher than those on the western side of the peninsula (Fig. 2). The
MARINE FLORA O F THE CAP BLANC PENINSULA
24
0
103
r
22 -
-
Ed 2o
18
-
16
I
'
J
I
I
I
I
I
1
I
1
I
I
1
F
M
A
M
J
JI
A
S
0
N
D
Months
Figure 2. Mean monthly sea water temperature (surface) recorded a t a station within the Baie
du Lkvrier (A) and one to the west of Cap Blanc (B) during 1967 (see Fig. 1).
salinity is also somewhat greater (37 t o 38"/,,) t o the east of the peninsula as a
result of increased evaporation and the slow replacement of water in the bay.
Higher surface temperatures and salinities suggest that the Baie du Lkvrier is
less influenced by the upwelling of deeper water than areas t o the west of Cap
Blanc.
The Baie du Lkvrier side of the Cap Blanc peninsula is relatively protected
whilst the western side is exposed to considerable wave-action. The amplitude
of the tides is comparatively small and each tide is somewhat higher on the
eastern side of the peninsula. The tidal data for ports on each side of the Cap
Blanc peninsula are given below in metres above Chart Datum: MHWS
MHWN
MLWS
MLWN
1.43
1.00
0.18
0.61
2.22
1.74
0.49
0.97
La Ciierra, Western Sahara
( 20"50', 17"06')
Nouadhibou, Mauritania
(20°55',17'02')
PATTERNS O F LITTORAL ZONATION
The localities at which descriptions and collections were made are shown on
the map of the Cap Blanc peninsula (Fig. 1).
The main features of algal distribution at each side of these localities using
the terminology of littoral zonation of Lewis (1961) is given below.
Baie de I'Etiole (site 1)
This, the most northerly of the localites visited, is situated in a very sheltered
position on the Baie du LCvrier side of the Cap Blanc peninsula. The Baie de
1'Etiole is largely filled with salt marsh and entering it from the south and
turning westwards into the bay is a tidal creek. The main mud flat in the centre
104
G . W. LAWSON AND D. M. JOHN
of the bay appeared to be rather homogeneous and to be dominated by
Spartina maritima (Curtis) Fernald which reached down to the waters edge on
the scoured north bank of the creek but a rather distinct zonation was observed
on the gently sloping southern bank. The uppermost part of this bank, in a
position inundated only occasionally by high tides, bore a number of
halophytes notably Salicornia fruticosa (L.) L. and Sesuvium portulacastrum
(L.) L. Below this was a rather bare area containing shallow pools in which
occurred either Enteromorpha clathrata alone or Chaetomorpha brachygona
accompanied by Rhizoclonium implexum. Further down the slope occurred
Spartina maritima and a belt, terminating at about the level of low water neaps,
of the small sea grass Halodule wrightii Ascherson, the limp leaves of which rest
on the surface of the muddy or sandy substratum at low water. Occasional
patches of Enteromorpha intestinalis subsp. intestinalis and Rhizoclonium
africanum were found amongst the Halodule.
Fine brown filaments of Feldmannia irregularis grew on shells at the bottom
of this belt of rather bare mud but below and reaching into the sublittoral was
a vigorous growth of another and larger sea grass Cymodocea nodosa (Ucria)
Ascheron which bore many epiphytes including Dictyota bartayresii, D.
dichotoma, Cevamium gracillimum var. byssoideum, Erythrotrichia carnea, and
fragments of a Cladophora species. Towards the mouth of the creek the sea
grass community gradually petered out and gave way to a mud flat covered by
shells and stones on which grew a number of small algae including Bachelotia
antillarum, Gelidium pusillum var. pulvinatum and Rhizoclonium implexum.
A notable feature of this sheltered bay was the absence of mangrove
vegetation, the northern limit of which is just to the north of St Louis in
SCnCgal about 570 km t o the south of Cap Blanc (Trochain, 1940).
Pointe de I’Etiole to Pointe des Maures (site 2)
On the southern border of the Baie de l’Etiole, where it enters the sea, there
is a low cliff about 3 m high rising above the mud flats already described. The
upper metre or so of cliff was rather bare although on similar rocks in a
somewhat more wave-exposed position further south the blue-green alga
Entophysalis deusta was found at this level. The next half metre or so of cliff
was sparsely covered by barnacles and the snail Littorina cingulifera Dunker
followed by another half metre of a much denser development of barnacles
with the larger snail Monodonta colubrina and Gelidium pusillum in cracks.
The lowermost metre of cliff was the region where the algae grew in most
abundance. Here, there was a relatively thick growth of Gelidium pusillum
mixed with some Bachelotia antillarum and occasional strands of Rhizoclonium
implexum. The most common alga on the small rocks littering the platform at
the base of the cliff was Gigartina acicularis.
The rock platform was gently sloping and in the shallow sublittoral was a
rich and varied community of seaweeds. The rather patchy nature of this
community was indicated by the presence of darker areas of vegetation and
lighter ones of sand seen below the water surface when viewed from the cliffs
above. This sublittoral community was dominated by Spyridia hypnoides and
species of Cystoseira including C. tamariscifolia. Sargassum vulgare was present
but not abundant and in some of the patches the marine grass Cymodocea
MARINE FLORA OF THE CAP BLANC PENINSULA
105
nodosa was a common constituent. Forming an undergrowth beneath these
larger plants were many smaller species among which were the following:
Amphiroa fragilissima, Champia parvula, Cladophora prolifera, Derbesia furcellata, Gelidiopsis variabilis, Gigartina acicularis, Jania rubens, Laurencia obtusa,
Ophiocladus simpliciuscula, Padina vickersiae, Plocamium raphlesianum, and
Pt erosiphonia pennata.
On the larger algae epiphytes were abundant and included Centroceras
clavulatum, Dictyota dichotoma, D, ciliolata, Colpomenia sinuosa, Herposiphonia tenella (including variety secunda), Hypnea musciformis, Heterosiphonia wurdemannii, Laurencia obtusa, and several species of Ceramium
including C. stricturn. Probable constituents of this sublittoral community
found unattached in the drift were Codium tomentosum and Padina tetrastroma tica.
Lagoon (site 3)
At a locality close to Nouadhibou, just north of the airport, was a very large,
but shallow, lagoon believed to be open to the sea only periodically at spring
tides. The floor of this lagoon was almost completely covered by thick mats of
the blue-green algae Microcoleus lyngbyaceus and Schizothrix calcicola. The
southern shore of this lagoon was littered with the dried mats of these
blue-green algae, blown ashore by the Harmattan wind at the time of our visit
(November).
Nouadhibou (site 4 )
At Nouadhibou the sandy beach was liberally strewn with wrecks, both iron
and wooden, and these formed the main substratum for algal attachment.
Frequently a rather narrow belt of Enteromorpha intestinalis subsp. intestinalis
was present in the upper midlittoral along with barnacles. Below this was a
wider band dominated by blue-green algae. At the lowest levels just above the
sand, mussels were common and mixed with them was a low turf of algae
including Gelidium pusillurn var. pulvinatum, Giffordia mitchelliae, Feldmannia
irregularis, Herposip ho nia ten ella, Ery t h ro trichia earn ea, Gon io trich u m alsidii,
Acrochaetium seriatum, and a species of Cladophora.
Cansado (site 5 )
Cansado Point is formed of a low sandstone cliff jutting out into the Baie du
Lkvrier at the southern end of Cansado bay. The south side of this point near
the Cansado Hotel was fairly sheltered and perhaps polluted with sewage,
whereas the eastern and northern parts of the point received more wave-action
and were less polluted. In sheltered parts of the littoral fringe the rocks were
apparently populated solely by Littorina cingulifera, L. neritoides L. and
a species of Monodonta, but with some wave-exposure these snails were
accompanied by Entophysalis deusta. Flat shelves of rock at this level receiving
spray but, not draining easily, were covered by a thick coating of the blue-green
algae Schizothrix calcicola and Microcoleus lyngbyaceus. The eulittoral zone
could be divided into three fairly distinct subzones-an upper subzone with a
106
G. W. LAWSON AND D . M. J O H N
thick covering of barnacles, a middle subzone dominated by an algal turf
consisting of Gelidium pusillum and Caulacanthus ustulatus accompanied by
patches of Enteromorpha jlexuosa subsp. jlrxuosa and Ulva lactuca, and a
lower subzone of mussels with Ralfsia expansa, Feldmannia irregularis, and
Corallina berterii. Near sewage outfalls a low felt of such blue-algae as
Microcoleus lyngbyaceus locally covered the lower part of the eulittoral zone.
Fragments of Cymodocea nodosa and Codium decorticatum bearing epiphytic
Herposiphonia tenella, Entocladia viridis, and species of Polysiphonia and
Enteromorpha, were present in the drift and it is likely that the offshore
sublittoral community was similar to that described for the area between
Pointe de 1’Etiole and Pointe des Maures.
Cap Blanc-east side (site 6 )
Access to the shore in the vicinity of Cap Blanc is difficult and only one
locality was visited on its eastern side. It lay about 3 km to the north of the
Cape at a point where the cliff was broken and where massive boulders had
fallen into the sea. The rocks were only moderately exposed to wave-action.
Here the littoral fringe was dominated by Littorina cingulijera and L. neritoides
with a species of Monodonta present in the lower part of this zone. With some
shade a blackening of the rock surface caused by Entophysalis deusta occurred.
The upper limit of the eulittoral zone was defined by a good development of
barnacles accompanied by Patella intermedia Jeffrey and P.safiana Lamark. In
the lower part of the barnacle zone was a very low, red algal turf of intermixed
Gelidium pusillum var, pulvinatu m and Caulacan th us ustulatus. Hilden brandia
canariensis was found in deep rock crevices, and on more sheltered rocks
lacking barnacles a blackish-green gelatinous layer of Entophysalis deusta had
developed.
Cap Blanc- west side (site 7)
About 1.5 km north of the tip of Cap Blanc, the high cliffs give way to a
sandy beach with sandstone outcrops. Observations were made in this, the most
wave-exposed shore studied. Here the Entophysalis deusta crust was thick and
formed a wide belt whose upper limit was up to 5 m above the sandy beach.
Littorina punctata and L. neritoides penetrated about half way up this belt and
extended below it over a rather bare region containing small plants of a
Porphyra species and other algae such as the blue-green algae Calothrix
crustacea and Entophysalis deusta, especially where there was some shade
under rock overhangs. Further down the shore was a fairly well-developed but
patchy algal belt dominated by green algae such as UIva lactuca, U. fasciata and
Enteromorpha prolifera subsp. prolifera, but also including Gifforida mitchelliae and Porphyra species. Barnacles were poorly developed but some large
limpets were present. Finally just above the level of the sand was a narrow belt
of Gelidium pusillum. On nearby flatter rocks of the lower midlittoral, which
projected above the sandy beach, was a very varied community of often
intricately intertwined algae which included Bryopsis corymbosa, Callithamnion granulatum, Champia parvula, Codium decorticatum, Corallina berterii,
Gelidium crinale, Gigartina acicularis, G. pistillata, Gracilaria verrucosa,
MARINE FLORA O F THE CAP BLANC PENINSULA
107
Gymnogongrus patens, Hypoglossurn woodwardii, Laurencia pinnatifida,
Ophiocladus sirnpliciuscula, Plocamium cartilagineum, Polysiphonia denudata,
P. macrocarpa, Pterosiphonia pennata and Rhodymenia pseudopalmata. Gracilaria foliifera mixed with goose barnacles often formed a dense covering on
more vertical rocks. Although the sandy beach did not permit the development
of a sublittoral fringe the presence of Ecklonia muratii in the drift indicated
that a sublittoral community was present in somewhat deeper water.
La Guerra (site 8)
Rocky outcrops on the sandy beach in the bay at La Guerra, just north of
the police station, were examined. These rocks received some shelter from the
rocky point lying to the west of the bay and are described as only moderately
exposed to wave-action. The uppermost algae at this locality were species of
blue-green algae such as Calothrix crustacea and Entophysalis deusta which
were on flat rocks and at the same level as small snails. Immediately below
these blue-greens was a belt of Ulva rigida with some Laurencia pinnatifida and
Gelidium pusillurn. Finally, on a very gently sloping rocky platform of the
lower eulittoral was a mixed carpet of the following algae: Ceramium rubrum,
Corallina berterii, Gelidium crinale, G. sesyuipedale, Gigartina acicularis,
G. teedii, Gracilaria foliifera, G. verrucosa, G-vmnogongrus patens, Hypnea
rnusciformis, H. spinella, Erythroglossum schousboei, Ophiocladus sirnpliciuscula, Plocamium cartilagineum, Pterosiphonia pennata, Rhody menia pseudopalmata and Spatoglossum schroederi. Attached plants of Ecklonia rnuratii and
Codium decorticatum, indicating a sublittoral fringe, were found at the
extreme outer limit of the rocky platform. Both of these species were richly
covered by epiphytes, Giffordia rallsiae and Griffithsia species on the former
and Ceramium rubrum, Erythrocladia irregularis, Erythrotrichia boryana,
Colaconema humilis and Polysiphonia denudata on the latter.
General features of zonation
The littoral fringe was characteristically populated by littorinids and, where
there was sufficient spray or shade to allow it to survive, by a blackish crust of
the blue-green alga Entophysalis deusta. We did not find any species of the
characteristic Bostrychia-Murrayella-Lophosiphonia community found on
rocks in the littoral fringe in many other parts of the West African coast. This
may possibly be attributed to the fact that prevailing climatic conditions cause
extreme desiccation of algae, expecially in the higher zones on the shore during
periods of low water.
The eulittoral zone could generally be divided into two subzones, an upper
subzone dominated by barnacles and a lower subzone dominated by algae. The
barnacle subzone was generally poor in algae but in sheltered parts contained
Enteromorpha spp., Gelidium pusillurn, especially in cracks in the rocks, and in
more exposed parts a few plants of Porphyra. In wave-sheltered places the
lower subzone was covered by a short turf of red algae, mostly of Gelidium
pusillurn, but mixed with Caulacanthus ustulatus where there was somewhat
increased wave-action, and including other species such as Gigartina acicularis,
Bachelotia antillarum and Ulva lactuca at the lower levels. In some places the
108
C. W. LAWSON A N D D. M. J O H N
lower subzone itself could be considered as consisting of two subordinate zones
with mussels and Corallina berterii characterizing the lower of these. On more
wave-exposed shores the lower eulittoral subzone consisted of a very varied
community of small species of algae in which no dominant species could be
discerned.
The sublittoral fringe was dominated by Sy,yridia, Cjjstoseira and Cymodocea in sheltered situations but included an undergrowth of such genera as
Padina and Amphiuoa. In more wave-exposed places the characteristic
components of the community included Ecklonia, Codium and Gracilaria. Sea
urchins, usually a common constituent of this zone, particularly in waveexposed situations, were very infrequent.
DISCUSSION
One of the results of this survey has been t o almost double (from 39 t o 6 5 )
the previously known marine algal flora identified t o species of former Spanish
Sahara. For Mauritania, the algal flora of which was somewhat better-known,
the increase is less spectacular but 43 species, including drift plants collected at
Nouakchott, have been recorded for the first time, providing a total of 158
species of marine algae now known from that country. The check-list of algal
species recorded for the combined coastlines of Mauritania and Western Sahara
is now 180 (excluding Cyanophyceae) whilst at least a further 23 plants are
identified only to genus.
One of the most striking features of the algal vegetation of the Cap Rlanc
peninsula was the very considerable differences found between its eastern and
western sides. These include differences both in the structure as well as the
composition of the communities found on the two sides. Ninety-seven algae are
known from the Cap Blanc peninsula from specific localities; this figure is
based on our own records and those given in works such as those of Hariot
(1911), Sourie (1954a) and Dangeard (1952). Of this total, 35 species were
found exclusively on the west side, 41 were restricted t o the eastern side, and
only 21 were common t o both sides. Two factors are probably chiefly
responsible for these differences. On the one hand the western coast is directly
exposed t o the action of the Atlantic waves whereas the eastern coast faces into
the sheltered Baie du Ltvrier. On the other hand the western coastal waters are
subjected to the direct effect of cold upwelling whereas in the Baie du Ltvrier
these effects are t o some degree moderated and the shallow nature of the bay
allows insolation to raise the temperature of the water above that of the open
sea (see Fig. 2). Probablv the temperature effect is more important than
wave-exposure in determining the presence or absence of algae on the two sides
of the Cap Blanc peninsula since many of the algal species found on the
western side, for instance, are ones which are known only further north o n the
coast of North-west Africa and beyond (Fig. 3). This applies to such species as
Gigartina pistillata, Gymnogongrus patens and Llictyopteris membranacea.
There is also a large percentage of species on the west side (23%) which extend
southwards only as far as Stntgal. These include such plants as Hypoglossum
woodwardii and Gelidium sesquipedale. The Gulf of Guinea element is little
represented (3%) on the western side of the peninsula. On the eastern side, by
way of contrast, many species (17%) such as Padina tetrastromatica, Dictyota
MARINE FLORA O F THE CAP BLANC PENINSULA
Nor th o f
Cap
Western
Blanc
Sahara
peninsula
109
Gulf
S8negal
of
Guinea
1
I
d
East
side
West
side
0
0
Figure 3. A diagrammatic representation of the proportionate distribution along t h e West
African coast of the algal species found o n the eastern and on the western side of the Cap Blanc
peninsula. The percentage contribution is indicated b y the widths of the bands.
bartayresii and Solieria tenera, are characteristically found to the south and in
the Gulf of Guinea and apparently reach their northernmost limit in the Baie
du Ltvrier.
The relations between the algal floras of the two sides of Cap Blanc and their
affinities with other regions of West Africa are summarized in Fig. 4. I t appears
that about half of the Cap Blanc flora is widely distributed along the West
I
Nor th
Cap
Western
Blanc
Sahara
peninsula
Gulf
Senegal
of
Guinea
I
Figure 4. A diagrammatic representation of the proportionate distribution along t h e West
African coast of the algal species in the marine flora of the Cap Blanc peninsula. Th e percentage
contribution is indicated b y the wiaths of t h e bands.
110
G. W. LAWSON AND D. M. JOHN
African coast, but about 38% of the species are totally absent from the Gulf of
Guinea. Less than 10%of the algal flora consists of plants known from the Gulf
of Guinea which find their northern limit at Cap Blanc. There is a small
element (3%) of algae endemic to the coasts of Mauritania and Stntgal, this
includes Cystoseira mauritanica and Rhizenteron saxatile. Cap Blanc represents
the southern limit for a number of species (21%) whilst Stntgal is the limit for
a further 16.5%.
The study of Sourie (1954a) has shown the transitional nature of the marine
algal flora and fauna of the Cap Vert peninsula. Although many northern
species find their southern limit in Stntgal and many southern species their
northern limit, there is nevertheless a considerable overlap with warm and
cooler water species occurring side by side. Our work demonstrates that this
transition zone of SknCgal extends through Mauritania t o the Cap Blanc
peninsula. Here the few surviving Gulf of Guinea species which penetrate north
as far as the Baie du Ltvrier finally disappear on the western side of the
peninsula, whilst a great many northern species do not extend any further
south than the tip of Cap Blanc. Thus the Cap Blanc peninsula can be regarded
as the true boundary between the warm temperate marine algal flora of North
West Africa and the sub-tropical transition zone of Mauritania and Senegal to
the south. This view receives independent confirmation from the work of
Postels (1968) who, taking into account oceanographic conditions alone,
considers Cap Blanc to be the boundary between two oceanographic regions of
West Africa. One to the north is characterized by colder water throughout the
year and the other region to the south is where the water is seasonally warmed
and cooled.
ANNOTATED SPECIES LIST
The following list includes all earlier records of algae specifically mentioned
as occurring in Western Sahara (assuming. territorial limits prior to 1958) and
Mauritania in addition to our own collections from the Cap Rlanc peninsula.
Sites at which collections and observations have been made are referred to by
number only, following the name and authority. A few plants collected in the
drift at Nouakchott are also included.
Baie de 1’Etiole
Pointe de 1’EtiolePointe des Maures
Lagoon
Nouadhibou
1
2
3
4
Cansado
Cap Blanc-east side
Cap Blanc-west side
La Giierra
Nouakchott
5
6
7
8
9
All specimens are deposited in the Ghana Herbarium (GC) at the Department
of Botany of the University of Ghana, Legon, Ghana.
Chlorophyceae
Bryopsis corymbosa J. Ag.
7
Bryopsis plumosa (Huds.) C. Ag.
7
Mauritania: Gayral (1966).
Very small plants growing among other algae
and having a roughly triangular outline to the
frond are assigned to this species. The main
branches were more robust (up to 5 0 0 p m in
diam.) than is usual for this species.
Caulerpa crassifolia (C. Ag.) J. Ag.
Mauritania: Seoane-Camba (1960).
MARINE FLORA O F THE CAP BLANC PENINSULA
Caulerpa cupressoides (West ex Vahl) C. Ag.
Mauritania: Feldmann (1951).
Caulerpa taxifolia (Vahl) C. Ag.
Mauritania: Feldmann (1951).
Chaetomorpha brachygona Harv.
1
Mauritania: Dangeard (1952), Feldmann
(19 38a), Trochain (1940).
Chaetomorpha linum (0.F. Mull.) Kiitz. 7
Western Sahara: Primo (1953) as Chaetomorpha aerea.
Cladophora fascicularis (Mert.) Kiitz.
Mauritania: Feldmann (1946).
See Lawson & Price (1969) for
comments o n the status of this taxon.
Cladophora prolifera (Roth) Kutz.
2
Cladophora spp.
23
Mauritania: Sourie (1954a).
A number of unidentifiable fragments of
species of this genus were found in
several of our collections.
Codium decorticatum (Woodw.) Howe 5,7,8
Mauritania: Hariot (1911), Schmidt &
Gerloff (1957) as C. elongatum.
Western Sahara: Primo (1953) as
C. elongatum.
Codium tomentosum Stackh.
2
Mauritania:
Gayral (1966), Hariot
(1911), Schmidt & Gerloff (1957).
Codium spp.
Mauritania: Sourie (1954a).
Derbesia furcellata (Zanard.) Ardiss
2
Our Mauritanian material appears t o
correspond in branching and dimensions
t o the plants described and figured as
Pseudochlorodesmus furcellata (Zanard.)
Bdrg. for the Canary Islands by Bdrgesen
(1925, figs 30-34).
It should be noted that Sourie (1954a)
mentions a new species of Derbesiu
found in Mauritania, Senkgal and neigh-
111
bouring islands, which was to have been
described by J. Feldmann under the
name D. souriei. As far as we can
ascertain, n o description has yet
appeared in print.
Enteromorpha clathrata (Roth) Grev.
1
Enteromorpha flexuosa (Wulf ex Roth) J.
Ag. subsp. flexuosa
475
Enteromorpha intestinalis (L.) Link subsp.
compressa Silva & Burrows
Western Sahara: Primo (1953) as E.
compressa. subsp. intestinalis
1,4,7
Enteromorpha prolifera (0. F. Miill.) J. Ag.
subsp. prolifera J . Ag.
437
Enteromorpha spp.
1,4,5,7,8
Small fragments attributable to this
genus were found in many of our collections.
Phaeophila viridis (Reinke) Burrows
5
Epiphytic on fragments of a Codium
found in the drift.
Rhizenteron saxatile Dang.
Mauritania: Sourie (1954a).
Rhizoclonium africanum Kutz.
1
Rhizoclonium implexum (Dillw.) Kiitz 1,2
Siphonocladus tropicus (Crouan frat.) J. Ag.
Mauritania: Feldmann (1946, 1951).
Struvea anastomosans (Harv.) Piccone &
Grunow
Mauritania: Steentoft (1967) with doubt.
Ulva fasciata Delile
7
Mauritania: Steentoft (1967).
Ulva lactuca L.
597
Mauritania: Hariot (1911), Schmidt &
Gerloff (1957), Steentoft (1967).
Western Sghara: Primo (1953).
Ulva rigida C. Ag.
8
Ulva spp.
4,7
Mauritania: Sourie (1954a).
Phaeophy ceae
Bachelotia antillarum (Grun.) Gerloff
2,s
Bifurcaria bifurcata Ross
Western Sahara: Primo (1953), Sourie (1954a)
as B. tuberculata.
Colpomenia sinuosa (Roth) Derb. & Sol.
2,s
Mauritania: Lawson (1966), Sourie (1954a);
Dickie (1874) as Asperococcus sinuosus.
Cystoseira baccata (S. G . Gmel.) Silva
Mauritania: ArdrC (1970). Gayral (1966),
Roberts (1967), Sauvageau (1912); Hariot
(1911), Roberts (1967), Sauvageau (1912) as C.
fibrosa.
Western Sahara: Sourie (1954a) as C. fibrosa.
Cystoseira foeniculacea ( L.) Grev.
Mauritania: Hariot (1911) with doubt,
Sauvageau (1912, 1920), Schmidt & Gerloff
(1957) as C. discors.
Western Sahara: Sourie (1954a) as C. abrotanifolia.
Cystoseira humilis Kutz. var. humilis
Mauritania: Ardrk (1970) as C. humilis.
Cystoseira mauritanica Sauv.
Mauritania: Dangeard (1937, 1938, 1949,
1952), Hariot (1911), Sauvageau (1912),
Schmidt & Gerloff (1957); Sauvageau (1920) as
C. tingitana.
Cystoseira myriophylloides Sauv.
9
Mauritania: Gayral (1966).
Cystoseira nodlcaulis (With.) Roberts
Mauritania: Dangeard (1938, 1949, 1952),
Seoane-Camba (1960) as C.granulata.
Cystoseira tamariscifolia (Huds.) Papenf.
192
Mauritania: Ardre (1970), Gayral (1966),
Roberts (1970); pdrgesen (1926), Hariot
(1911), Sauvageau (1912, 1913), Schmidt &
Gerloff (1957) as C. ericoides.
Western Sahara: Sourie (1954a) as C. ericoides.
112
G. W. LAWSON AND D. M. JOHN
Cystoseira spp.
1,9
Mauritania: Lawson (1966), Michanek (1971,
1975), Nizamuddin (1970), Sourie (1954a),
Southward (19 58), Stephenson & Stephenson
(1972).
Western Sahara: Feldmann (1951). Primo
(1953).
Dictopteris delicatula Lamour.
9
This plant was found only in the drift at
Nouakchott and this appears t o be the most
northerly record of its distribution in West
Africa.
Dictopteris membranacea (Stackh.) Batt
Mauritania: ArdrP (1970), Gayral (1966),
Seoane-Camba (1960).
Dictyota bartayresii Lamour.
1
Western
Sahara:
Kodriques (1960) as
D. barta yresiana.
We attach some doubt to our determination as
the Mauritanian plants showed less divergent
branching than is usually found in this species.
2
Dictyota citiolata Sonder ex Kutz.
Western Sahara. Rodriques (1960) as D. ciliata.
Dictyota crenulata J. Ag.
Mauritania: Feldmann (1951).
Dictyota dichotoma (Huds.) Lamour.
132
Mauritania: ArdrP (1970), Gayral (1966).
Dictyota spp.
Mauritania: Lawson (1966), Sourie (1954a),
Southward (1958).
Dilophus spiralis (Mont.) Hamel
Mauritania: Ardrk (1970), Gayral (1966).
Ecklonia biruncinata (Bory) Papenf.
Mauritania: Schmidt & Gerloff (1957) as
E. radiata; Hariot (1911) as E. radiata var.
exasperata.
Ecklonia muratii J. Feldm.
7,s
Mauritania:
Bodard & Mollion (1974),
Dangeard (1952, 1958), Feldmann (1937.
1951)’ Lawson (1966), Michanek (1971,19751,
Sourie (1954a, 1954b), Stephenson &
Stephenson (1972).
Western Sahara: Feldmann (1937, 1946, 1951),
Lawson (1966), Sourie (1954a).
Ecklonia sp.
Mauritania: Southward ( 19 5 8).
Ectocarpus siliculosus (Dillw.) Lyngb.
Mauritania: Hariot (1911), Schmidt & Gerloff
(1957).
Feldmannia irregularis (Kutz.) Hamel
2,4,5
Fucus spiralis L.
Western Sahara: Feldmann (19 S l ) , Michanek
(1971, 1975), Primo (1953); Sourie (1954a) as
F. platycarpus.
Fucus spp.
Western Sahara: Michanek (1971, 1975), Primo
(1953).
Ciffordia granulosa (Sm.) Hamel
Mauritania: Schmidt & Gerloff (1957); Hariot
(1911), Schmidt & Gerloff (1957) as
Ectocarpus granulosus.
497
Ciffordia mitchelliae (Haw.) Hamel
Ciffordia rallsiae (Vickers) W . R. Taylor
8
The plants from Western Sahara closely correspond to this species although the somewhat
tapering plurilocular sporangia were smaller
than the dimensions normally given for it,
ranging from 50-70pm in length and about
20 prn in diameter.
Laminaria ochroleuca Pyl.
Mauritania: Michanek (1975).
Western Sahara: ArdrP (1970), Boney (1965),
Feldrnann (1955), Michanek (1971, 1975),
Primo (1953).
Laminaria spp.
Mauritania: Sourie (1954a).
Western Sahara: Primo (1953), Sourie (1954a).
Leathesia difformis (L.) Aresch.
Mauritania: Ardrk (1970), Gayral (1966).
Levringea atlantica (J. Feldm.) Kylin
Mauritania: Gayral (1960); Feldmann (1938b)
as Myriogloea atlantica.
Western Sahara: Dangeard (1952), Feldmann
(1946, 1951), Gayral (1960). Kylin (1940);
Feldmann (1938b) as Myriogloea atlantica;
Levring (19 39) as Myriogloia atlantica.
Lobophora vanegata (Lamour.) Womersley
Mauritania: Sourie (1954a) as Pocockiella
variega ta.
Western
Sahara:
Rodriques
(1960) as
Pocockiella variegata.
Padina pavonia (L.) Lamour.
Mauritania: ArdrP (1970), Bodard & Mollion
(1974), Gayral (1966), Hariot (1911), Schmidt
& Gerloff (1957).
Padina tetrastromatica Hauck
2
Drift specimens of this species were unusual in
that older parts of t h e fronds had concentric
rows of flattened fusiform leaf-like structures,
up t o about 1 m m long and about one quarter
as broad, growing in the position normally
occupied by sporangia. They appeared to arise
from superficial cells of the thallus and the fact
that they could easily be detached suggests the
possibility that they may function as vegetative
propagules.
Padina vickersiae Hoyt
2,9
Padina sp.
Mauritania: Lawson (1966), Sourie (1954a).
Phyllaria reniformis (Lamour.) Rostafinski ex
Born.
Western Sahara: Feldmann (1951).
Pilayella littoralis (L.) Kjellm.
Mauritania: Gayral (1966).
Ralfsia expansa (J. Ag.) J . Ag.
5
Mauritania: Sourie (1954a).
Saccorhiza polyschides (Lightf.) Batt.
Mauritania: Michanek (1975).
Western Sahara: ArdrP (1970), Boney (1965),
Gayral (1966), Michanek (1971, 1975), Norton
(1970); Primo (1953), Feldmann (1951) as
S.bulbosa.
Sargassum acinarium (L.) C . Ag.
Mauritania: Hariot (1911) as S. linifolium.
Sargassum vulgare C. Ag.
2,9
Mauritania: Hariot (1911), Hoppe (1969),
Levring
(1969),
Seoane-Camba
(1960),
Steentoft (1967).
Western Sahara: Primo (1953).
MARINE FLORA O F THE CAP BLANC PENINSULA
Sargassum sp.
Mauritania: Seoane-Camba (1960), Southward
(1958).
Spatoglossum schroederi (C. Ag.) Kiitz.
8,9
Spatoglossum solieri (Chauv. ex Mont.) Kiitz.
Mauritania: Bodard & Mollion (1974).
113
Sphacelaria furcigera Kiitz.
9
Taonia atomaria (Woodw.) J. Ag.
Mauritania: ArdrC (1970), Gayral (1966).
Lawson (1966), Sourie (1954a). Stephenson &
Stephenson (1972).
Rhodoph yceae
Acrosorium uncinatum (Turn.) Kylin
Mauritania: Seoane-Camba (1960), Trochain
(1940).
Western Sahara: Ar d r t (1970), Gayral (1966).
Amphiroa annulata Lemoine
2
Amphiroa fragilissima (L.) Lamour.
2
Amphiroa subcylindrica Dawson
2
This species has n o t previously been reported
outside the Pacific region.
Apoglossum ruscifolium (Turn.) J. Ag.
Western Sahara: Ardrt (1970), Gayral (1966).
Audouinella purpurea (Lightf.) Woelkerling
Mauritania: Dixon & Irivine (1977).
Audouinella secundata (Lyngb.) Dixon
Mauritania: Dixon & lrvine (1977).
AoudouineIla seriatum (BBrg.) Lawson & John,
comb. nov. (Achrochaetium seriatum Borg.) 4
In making this new combination we have
followed Dixon (Parke & Dixon, 1976) who has
placed several genera of acrochaetoid algae
occurring in th e British Isles into a single genus
Audouinella. He argues that there seems no
logical reason for delineating genera in this
closely interrelated group in which the circumscription of species is often confused.
Audouinella virgatula (Harv.) Dixon
Mauritania: Dixon & Irvine (1977).
Bostrychia binderi Harv.
4
A single fragment found entangled with filaments of Enteromorpha.
Calliblepharis ciliata (Huds.) Kutz.
Mauritania: Dixon & Irvine (1977), Gayral
(1966), Hariot (1911).
Calliblepharis jubata (Good. & Woodw.) Kiitz.
Mauritania: Ardrk (1970), Dixon & Irvine
(1977), Gayral (1966).
Calliihamnion decompositum J. Ag.
Mauritania: Halos (1965) as Aglaothamnion
decompositum.
Callithamnion sp.
7
According t o J. H. Price (in litt., 25.5.76) this
material collected from th e west side of Cap
Blanc may be an undescribed species.
Caulacanthus ustulatus (Mert.) Kutz.
5,6,7
Mauritania: Lawson (1966), Sourie (1954a).
Centroceras clavulatum (C. Ag.) Mont.
2
Mauritania: Lawson (1966), Sourie (1954a),
Stephenson & Stephenson (1972).
Ceramium diaphanum (Lightf.) Roth
Mauritania: ArdrC (1970), Gayral (1966).
Ceramium gracillimum (Kiitz.) Griff. & Harv.
variety byssoideum (Harv.) Mazoyer 1,2,8,9
Ceramium rubrum (Huds.) C . Ag.
8
This species has n o t previously been reported
further south than Morocco on the West
African coast.
8
Ceramium strictum Harv.
2
Ceramium spp.
7-8
Mauritania: Sourie (1954a).
Champia parvula (C. Ag.) Harv.
2,7,8
Chondria dasyphylla C. Ag.
Mauritania: Seoane-Camba (1960).
Chondria scintillans G . Feldm.
Mauritania: Ardrk (1970), Feldmann (1964).
Chondria tenuissima (Good. & Woodw.) C. Ag.
Western Sahara: Ardrb (1970), Gayral (1966).
Chondria spp.
Mauritania: Sourie (1954a).
Chondrus crispus Stackh.
Mauritania: Hariot (191 1).
Choreonema thuretii (Born.) Schmitz
Mauritania: Hariot (1911).
Colaconema humilis (Rosenv.) Woelkerling
8
Corallina berteri Mont.
5,7,8
Corallina mediterranea Aresch.
Mauritania: Ardrb (1970), Gayral (1966),
Hariot (1911).
Western Sahara: Primo (1953).
Corallina officinalis L.
Mauritania: ArdrC (1970), Gayral (1966).
Corallina sp,
Mauritania: Sourie (1954a).
Cryptonemia seminervis (C. Ag.) J. Ag.
Mauritania: Bodard (1971), Hariot (1911).
Cryptopleura ramosa (Huds.) Kylin e x Newton
Western Sahara: ArdrC (1970). Gayral (1966).
Dermatolithon cystoseirae (Hauck) Huvk
Mauritania: Huvk (1962). Lemoine (1965,
1966); Ardrk (1970) as D. cystoseirae var.
saxicola; Hamel & Lemoine (1953) as D.
papillosum.
Dermatolithon polydonum Fosl.
Mauritania: Lemoine (pers. c o m m . ) .
Erythrocladia irregularis Rosenv.
8
Erythroglossum schousboei J. Ag.
8
Erythrotrichia boryana (Mont.) Berth.
7.8
Erythrotrichia carnea (Dillw.) J. Ag.
1 3
Fosliella farinosa (Lamour.) Howe
9
Mauritania: John & Lawson (1972); Hariot
(1911) as Melobesia farinosa.
Gastroclonium ovatum (Huds.) Papenf.
Mauritania: Ardrk (1970), Gayral (1966).
Celidiopsis variabilis (J. Ag.) Schmitz
2,9
Mauritania,
Feldmann (1951), Steentoft
(1967).
Gelidium Iatifolium (Grev.) Born. & Thur.
Western Sahara: Ardre (1970), GayraI (1966);
Michanek (1971, 1975). Primo (1953) as G.
attenuatum.
Gelidium microdon Kiitz.
Western Sahara: Michanek (1971, 1975), Primo
(1953) as G. spinulosum.
114
G. W. LAWSON AND D. M. JOHN
Gelidium pusillum (Stackh.) Le Jol.
4,8
Mauritania: Sourie (1954a) with doubt; Hariot
(1911), Schmidt & Gerloff (1957), Steentoft
(1967) as G. crinale.
Western Sahara: Primo (1953) as G. crinale.
var. pulvinatum (C. Ag.) J. Feldm.
2,4,7,8
Mauritania: Dangeard (1951, 1952) as G.
rep tans.
We concur with BQrgesen (1943) in considering
Gelidium reptans t o be n o more than a variety
of G. pusillum even though it has been given
specific rank by some others.
Gefidiumsesquipedale (Clem.) Born. & Thur.
8
Mauritania: Ardrk (1970), Dangeard (1952),
Dixon & Irvine (1977), Gayral (1966), Hariot
(1911), Schmidt & Gerloff (1957).
Western Sahara: Michanek (1971, 1975), Primo
(1953).
Gelidium spp.
Mauritania: Sourie (1954a).
Western Sahara: Michanek (1971, 1975), Primo
(1953).
Gigartina acicularis (Wulf.) Lamour.
2,7,8
Mauritania: Ardrk (1970), Gayral (1966),
Hariot (1911), Schmidt & Gerloff (1957),
Sourie (1954a).
Gigartina‘pistillata (S. G. Gmel.) S t a c b .
7
Mauritania: Ardre (1970), Hariot (1911),
Schmidt & Gerloff (1957), Sourie (1954a).
Western Sahara: ArdrC (1970).
Gigartina stellata (Stackh.) Batt.
Mauritania: Dizerbo (1974).
Western Sahara: ArdrC (1970), Gayral (1966).
Gigartina teedii (Roth) Lamour.
8
Mauritania: Lawson (1966), Sourie (1954a)
with doubt.
Goniotrichum alsidii (Zanard.) Howe
4
Gracilaria armata (C. Ag.) J. Ag.
8
Mauritania: Hariot (1911).
Gracilaria bursa-pastoris (S. G. Gmel.) Silva
Mauritania: Hariot (1911) as G. compressa.
Gracilaria foliifera (Forssk.) BQrg.
73
Mauritania: Lawson (1966), Michanek (1971,
1975), Sourie (1954a); Hariot (1911) as G.
multipartita.
Gracilaria verrucosa (Huds.) Papenf.
73
Mauritania: ArdrC (1970), Steentoft (1967);
Hariot ( 19 11) as G. confervoides.
Western Sahara: Ardrk (1970). Gayral (1966);
Primo (1953) as G. confervoides.
Gracilaria spp.
Mauritania: Southward (1958).
Western Sahara: Michanek (1971, 1975). Primo
(1953).
Grateloupia doryphora (Mont.) Howe
Mauritania: Sourie (1954a) as G. lanceola.
Grateloupia filicina (Lamour.) C. Ag.
Mauritania: ArdrC (1970), Gayral (1966).
Griffithsia sp.
8
The specimens from Western Sahara had
branches consisting of large, obovoid to harrelshaped cells and closely correspond in vegetative structure t o Griffithsia schousboei and G.
opuntioides. It is n o t possible to attribute our
specimens t o either of these species as all the
plants were sterile and they are separated on
the position of the spermatangial sori.
Gymnogongrus crenulatus (Turn.) J. Ag.
Mauritania: Dixon & lrvine (1977); ArdrC
(1970). Gayral (1966), Hariot (1911). Schmidt
& Gerloff (1957) as G . norvegicus.
Gymnogongrus griffithsiae (Turn.) Mart.
Mauritania: Dixon & Irvine (1977), Hariot
(1911), Schmidt & Gerloff (1957).
Gymnogongrus patens (Good. & Woodw.) J. A.g7,8
Mauritania: Gayral (1966).
Haliptylon squamatum (L.) Johansen, L. Irvine &
Webster
Western Sahara: Ardrk (1970), Gayral (1966) as
Corallina squamata.
2
Haliptylon subulata (Ellis & Soland.) Johansen
Halopitys incurvus (Huds.) Batt.
9
Mauritania: Ardrk (1970), Gayral (1966);
Hariot (1911) as H. pinastroides.
Halurus equisitifolius (Lightf.) Kiitz.
Mauritania: ArdrC (1970), Gayral (1966),
Sourie (1954a).
Herposiphonia tenella (C. Ag.) Ambronn
2,4,5
var. subsecunda Hollenberg
2
Heterosiphonia plumosa (Ellis) Batt.
Western Sahara: Ardre (1970), Gayral (1966).
Heterosiphonia wurdemanni (Baily e x Harv.)
Fa1ke nb .
9
var. laxa BQrg.
2
Hildenbrandia canariensis BQrg.
6
Mauritania: ArdrC (1970).
The plants reported under this name formed
thick, reddish-violet crusts which superficially
resemble a Peyssonnelia. I t differs from H.
prototypus by its thick crust, very immersed
conceptacles, and the tetrasporangia divided by
almost parallel walls.
Hypnea cervicornis J. Ag.
Mauritania. Bodard (1968).
Hypnea flagelliformb Grev. ex J. Ag.
Mauritania: Bodard (1968).
Hypnea musciformis (Wulf.) Lamour.
2,7,8,9
Mauritania: Bodard (1968), Hariot (1911),
Hoppe
(1969),
Seoane-Camba
(1960),
Steentoft (1967).
Hypnea spinella (C. Ag.) Kiitz.
8
Hypnea unilateralis Dang.
Mauritania: Bodard (1968).
Western Sahara: Bodard (1968).
Hypnea s p
Mauritania: Bodard (1968) as “Hypnea sp. (aff.
ceramioides)”.
Hypoglossum woodwardii Kiitz.
Western Sahara: ArdrC (1970), Gayral (1966),
Seoane-Camba (1960).
Jania adhaerens Lamour.
2
Jania longifurca Zanard.
Mauritania: Feldmann (1939), Hariot (1911),
Seoane-Camba (1965).
Jania rubens (L.) Lamour.
2
Mauritania: Ardri (1970), Gayral (1966).
Hariot (1911).
Laurencia flexuosa J. Ag.
Mauritania: Seoane-Camba (1960) with doubt.
MARINE FLORA O F THE CAP BLANC PENINSULA
Laurencia obtusa (Huds.) Lamour.
2
Mauritania: Hariot (1911).
Laurencia pinnatifida (Huds.) Lamour.
7.8
Mauritania: Ardre (1970), Dangeard (1952),
Gayral (1966), Hariot (1911), Lawson (1966),
Sourie (1954a), Steentoft (1967).
Laurencia spp.
Mauritania: Stephenson & Stephenson (1972).
Leptophytum bisporum (Fosl.) Adey
Mauritania: Lemoine (1963) as Lithothamnium
bisporum.
Lithophyllum corallinae (Crouan frat.) Heydr.
Mauritania:
Hariot (1911) as Melobesia
corallinae.
(Rothplatz)
Lemoine
Lithophyllum
haucki
Mauritania: Feldmann (1939).
Lithophyllum incrustans Phil.
Mauritania: Adey & Adey (1973), Ardrh
(1970), Feldmann (1939), Gayral (1966),
Hamel & Lemoine (1953), Hariot (1911),
Seoane-Camba (1965).
Western Sahara: Adey & Adey (1973).
Lithophyllum lobatum Lemoine
Mauritania: Lemoine (1963).
Lithophyllum tortuosum (Esper) Huve
Mauritania: Sourie (1954a).
Lithoporella conjuncta (Fosl.) Fosl.
Mauritania: De Toni (1924), Foslie (1909),
Foslie & Printz (1929); Lemoine (1963) as
L. melo besioides.
Lithothamnium fruticulosum (Kiitz.) Fosl.
Mauritania: Lemoine (1963).
Lithothamnia sp.
Western Sahara: Primo (1953).
Lomentaria articulata (Huds.) Lyngb.
Western Sahara: ArdrC (1970), Gayral (1966).
Lomentaria bayleyana (Harv.) Farlow
Mauritania: Seoane-Camba (1960).
Melobesia membranacea (Esper) Lamour.
Mauritania: Hariot (191 1) as Lithothamnion
membranaceum.
Mesophyllum ectocarpon (Fosl.) Adey
Mauritania: Bdrgesen (1929), De Toni (1924),
Foslie (1907), Foslie & Printz (1929), Lemoine
(1963) as Lithothamnium ectocarpon.
Mesophyllum lichenoides (L.) Lemoine
Mauritania: Ardrb (1 970).
Western Sahara: Gayral (1966).
Mesophyllum solutum (Fosl.) Lemoine
Mauritania: Lemoine (1963); Hariot (1911) as
Lithothamnion solutum.
Nemalion helminthoides (Vell.) Batt.
Western Sahara: Primo (1953).
Neogoniolithon mamillosum (Hauck) Setch. &
Mason
Mauritania: De Toni (1924) as Goniolithon
mamillosum form microcarpa.
Ophidocladus simpliciuscula (Crouan frat.) Falkenb.
2,733
Cap Blanc represents a new southern limit for
this species.
Phymatolithon calcareum (Pall.) Adey & McKibbin
Mauritania: Bdrgesen (1929), Lemoine (1928)
as Lithothamnion calcareum.
9
Platysiphonia miniata ( C . Ag.) Bdrg.
115
Plocamium cartilagineum (L.) Dixon
7,s
Mauritania: ArdrC (1970), Gayral (1966),
Hariot (1911) as P. coccineum.
223
Plocamium raphelisianum Dang.
Pterosiphonia pennata (C. Ag.) Falkenb.
2,7,8
R hodymenia corallicola Ardiss.
Mauritania: Hoppe (1969), Seoane-Camba
( 1960).
Rhodymenia pseudopalmata (Lamour.) Silva
7,8
Mauritania: Hariot (1911) as R . palmetta.
Rytipholea tinctoria (Clem.) C. Ag.
9
Mauritania: ArdrC (1970). Gayral (1966),
Seoane-Camba (1960).
Solieria chordalis (C. Ag.) J. Ag.
Mauritania: Seoane-Camba (1960).
Solieria tenera (1. Ag.) Wynne & W. R. Taylor
Mauritania: Feldmann (1951), Hariot (1911) as
Agardhieila tenera.
Polysiphonia denudata (Dillw.) Grev. ex Harv. 7,8
Mauritania: Seoane-Camba (1960) as P.
variegata.
Some doubt attaches t o this identification since
the Cap Blanc plants grew o n open waveexposed shores whereas this species is usually
reported from sheltered and more brackish
water localities.
The plants referred to this species had 6
pericentral cells surrounding a very small axial
cell and cortication developing towards the base
of the larger branches. The segments near the
base of the branches were up t o 4 5 0 p m in
diameter, narrowing towards t h e apex of the
branches and were generally shorter than broad.
Cystocarps borne o n the upper branches were
sessile o r o n a 1-celled stalk, obovate and from
3 S(t400 p m in diameter.
Polysiphonia macrocarpa Harv.
Z7-8
On a number of occasions a sterile 4 pericentral-celled plant was found which has
tentatively been placed under this species.
Polysiphonia spp.
5,7,8
Small unidentifiable fragments probably referrable to this genus have been found in a number
of collections.
Porphyra sp7
This small Porphyra had fronds oblong in
outline, plicate, and with a dentate margin. In
section the fronds were about 4 0 p m thick with
t w o layers of cells, each cell was about 16 pm
in height and 1 0 p m in diameter in surface
view.
Povolithon africanum (Fosl.) Fosl.
Mauritania: Lemoine (1963) as Lithophyllum
africanum.
Pseudolithophyllum expansum (Phil.) Lemoine
Mauritania: Bdrgesen (1929), Edelstein (1964),
Feldmann (1939), Gayral (1958); Hariot
(1911) as Lithophyllum expansum form exigua.
Pterocladia capillacea ( S . G. Gmel.) Born. & Thur.
Mauritania: Feldmann (1939), Lawson (1966),
Sourie (1954a).
Western Sahara: Ardrc? (1970), Gayral (1966).
Pterosiphonia complanata (Clem.) Falkenb.
Mauritania: Ardrh (1970), Gayral (1966).
116
G. W. LAWSON AND D. M. JOHN
Spyridia filamentosa (Wulf.) HaN.
Mauritania: Seoane-Camba (1960).
Spyndia hypnoides (Bory ex Belanger) Papenf. 2,9
Mauritania: Feldmann (1938), Steentoft (1967)
with doubt as S. aculeata; Dangeard (1952) as
S. aculeata variety hypnoides.
Cyanophy ceae
Calothrix crustacea Thur. ex Born. & Flah. 4,5,7,8
Entophysalis conferta (Kutz.) Dr. & D.
5
Entophysalis deusta (Menegh.) Dr. & D. 2,4,5,6,7,8
Microcoleus lyngbyaceus (Kutz.) Crouan frat. ex
Gorn.
3,4,5,7,8
Porphyrosiphon notarisii (Menegh.) Kutz. ex Gom.4
Schizothrix arenaria (Berk.) Gom.
5
Schizothrix calcicola (C. Ag.) Gom. ex Gom. 3,5,6,8
Schizothnx tenerrima (Gom.) Dr.
4
ACKNOWLEDGEMENTS
The field work for this study was supported by a UNESCO grant. Thanks are
due to Monsieur Paul Piesson, Laboratoire de Geologie, Louvain-La-Neuve,
Belgium and Herr. Hans Moln, Voest-Alpine, Nouadhibou, Mauritania, for their
assistance in the field; to Sy Moussa Arouna, Le Directeur, Laboratoire des
Ptches, Nouadhibou, for providing us with unpublished data; to Dr F. Drouet
and Mr E. Anderson, Academy of Natural Sciences of Philadelphia, U.S.A., to
Dr Helen Blackler, Department of Botany, University of St Andrews, Scotland,
and to Dr H. W. Johansen, Department of Biology, Clark University,
Massachusetts, U.S.A., for assistance in identifying specimens; to Mr J . H. Price,
Botany Department, British Museum (Natural History), London, for invaluable
assistance with the literature; and t o Professor G. C. Clerk, Head of the Botany
Department, University of Ghana, Legon, for allowing us facilities in his
Department.
REFERENCES
ADEY, W. H. & ADEY, P. J., 1973. Studies o n the biosystematics and ecology of the epilithic crustose
C o r a h a c e a e of the British Isles. British Phycological Journal, 8: 343-407.
ARDRg, F., 1970. Contribution l’ktude des algues marines du Portugal I-La Flore. Portugaliae Acta
Biologica, Scr. B, 10: 1-423.
BODARD, M., 1966. Premiere liste des esphces d’algues presentes sur la Point de Sarene (Shegal). Notes
Africaines, 111: 81-9.
BODARD, M., 1968. Les Hypnea au Senegal (HypnPacCes, Gigartinales). Bulletin de l’lnstitut
Fondamental d’Afrique Noire, Scr. A , 30: 81 1-29.
BODARD, M., 1971. Sur un genre nouveau de Delesseriackes: Pseudobranchioglossum senegalense, algue
de l’infralittoral shigalais. Bulletin de l’lnstitut Fondamental d ’ Afrique, Noire, Sku. A, 33: 20-31.
BODARD, M. & MOLLION, J., 1974. La vegetation infralittorale de la petite cbte sCn6galaise. Bulletin
Sociktk Phycologique de France, 19: 193-221.
BONE”, A. D., 1965. Aspects of the biology of the seaweeds of economic importance. Advances in
Marine Biology, 3: 105-253.
BORGESEN, F., 1925. Marine algae from the Canary Islands especially from Teneriffe and Gran Canaria.
1. Chlorophyceae. Kongelige Danske Videnskabernes Selskabs Skrifrer, 5: 1-123.
BORGESEN, F., 1926. Marine algae from the Canary Islands expecially from Teneriffe and Gran Canaria.
11. Phaeophyceae. Kongelige Danske Videnskabernes Selskabs Skrifter, 6: 1-112.
BORGESEN, F., 1929. Marine algae from the Canary Islands especially from Teneriffe and Gran Canaria.
111. Rhodophyceae, Pt. 11. Cryptonemiales, Gigartinales and Rhodymeniales. Les MClobesi6es par Mme.
P. Lemoine. Kongelige Danske Videnskabernes Selskabs Skrifter, 8: 1-97.
BORGESEN, F., 1943. Some marine algae from Mauritius. 111. Rhodophyceae. Pt. 2. Gelidiales,
Cryptonemiales, Gigartinales. Kongelige Danske Videnskabernes Selskabs Skrifter, 1 9 : 1-85.
DANGEARD, P., 1937. Sur les zones d’algues marines du Maroc occidental. Comptes Rendus
Hebdomadaires des Skances de 1;lcadkmie des Sciences, Skrie, 204: 795-7.
MARINE FLORA O F THE CAP BLANC PENINSULA
117
DANGEARD, P., 1938. Sur un Cystoseira nouveau de la presqu’ile du Cap Vert, C. senegalensis sp. nov.
et sur quelques autres Cystoseira africains. Comptes Rendus Hebdomadaires des Stances de 1;lcadkmie
des Sciences, Skrie, 206: 203-204.
DANGEARD, P., 1949. Les algues marines de la cbte occidental du Maroc. Le Botaniste, 34: 89-189.
DANGEARD, P., 1951. Sur les GClidiacCes d e Dakar et d e Port Etienne. Le Botaniste, 35: 21-24.
DANGEARD, P., 1952. Algues de la presqu’ile du Cap Vert (Dakar) e t ses environs. Le Botaniste, 36:
193-329.
DANGEARD, P., 1958. Notice sur les travaux scientific (1931-1956) d e M. Pierre Dangeard. Le Botaniste,
42, Supplkment: 1-98.
DE TONI, G. B., 1924. Sylloge algarum omnium hucusque cognitarum. IV. Sylloge Floridearum omnium
hucusque cognitarum. Sect. V . Patavii. Padva.
DICKIE, F., 1874. Enumeration of algae collected at the Cape Verde Islands by H. N. Moseley, M.A.,
naturalist to H.M.S. ‘Challenger’. Journal o f the Linnean Society (Botany), 14: 344-349.
DIXON, P. S. & IRVINE, L., 1977. Seaweeds of the British Isles, Vol. 1. Rhodophyta, Part 1 .
Introduction, Nemaliales, Gigartinales. London: British Museum (Natural History).
DIZERBO, A.-H., 1974. La repartition des Gigartina (Gigartinales, Gigartinaches) des Massif Armoricain.
Bulletin Socidtk Phycologique de France, 19: 88-94.
EDELSTEIN, T., 1964. On the sublittoral algae of the Haifa Bay area. Vie Milieu, 15: 177-210.
FELDMANN, J., 1937. Sur une nouvelle espkce de Laminariacbe de Mauritanie: Ecklonia muratii nov. sp.
Bulletin de la Soci&& d’Histoire Naturelle de I’Afrique du Nord, 28: 325-327.
FELDMANN, J., 1938a. Sur la repartition du Diplanthera wrightii Aschers. sur la c6te occidentale
d’Afrique. Bulletin de la Socikth d’Histoire Naturelle de I’Afrique du Nord, 29: 107-112.
FELDMANN, J., 1938b. Sur une nouvelle expkce de PhCophycee du Rio de Oro: Myriogloea atlantica
nov. sp. Bulletin de la Sociktbd’Histoire Naturelle de 1’Afrique de Nord, 29: 113-116.
FELDMANN, J., 1939. Les algues marines de la cbte des Albkres IV. RhodophycCes. Revue Algologique,
11: 247-330.
FELDMANN, J., 1946. La flore marine des Iles Atlantides. Mkmoires de la Sociktk de Biogkogvaphie, 8:
395-43s.
FELDMANN, J., 1951. La flore marine de I’Afrique de Nord. Compte Rendus Sommaire des oCI.zces.
Socittb de Biogtographie, 8: 103-108.
FELDMANN, J., 1955. La zonation des algues sur la cbte Atlantique du Maroc. Bulletin de la Socihtk des
Sciences Naturelles du Maroc, 35: 9-17.
FELDMANN, J., 1964. Sur une nouvelle espkce iridescente de Chondria (Rhodophyceae, Rhodomelaceae). Revue G&nkraledeBotanique,71: 45-55.
FOSLIE, M., 1907. Algologiske notiser IV. Kongelige Norske Videnskabernes Selskabs Skrifter, 6 : 1-30.
FOSLIE, M., 1909. Algologiske notiser VI. Kongelige Norske Videnskabernes Selskabs Skrifter, 2: 1-63.
FOSLIE, M. H. & PRINTZ, H., 1929. Contribution to a monograph of the Lithothamnia. Trondheim.
GAYRAL, P., 1958. La Nature au Maroc II. Algues de la c6te atlantique marocaine. Rabat.
GAYRAL, P., 1966. Les algues des c6tes frangaises (Manche et Atlantique). Notions fondamentales sur
l’eologie, la biologie et la systtmatique des algues marines. Paris: Derens & Cie.
HALOS, M. T., 1965. Sur trois CallithamniPes des environs de Roscoff. Cahiers de Biologie Marine, 6:
117-134.
HAMEL, G . & LEMOINE, P., 1953. Corallinackes de Prance e t d’Afrique d u Nord. Archives du M u s h m
National d’Histoire Naturelle, S&r, 7, 1: 15-136.
HARIOT, P., 1911. Algues de Mauritanie recueillies par M. Chudeau. Bulletin Socittt Botanique de
France, 58: 438-445.
HOPPE, H. A., 1969. Marine algae as raw materials. In Levring, T., Hoppe, H. A. & 0. J . Schmid, Marine
Algae-A survey of research and utilization. Botanica Marina Handbooks, 1. Hamburg: Cram, De
Gruyter & Co.
HUV6, H., 1962. Taxonomie, ecologie et distribution d’une Mklobesike MCditerranCenne: Lithophyllum
papillosum (Zanardini) comb. nov., non Lithophyllum (Dermatolithon) papillosum (Zanard.) Foslie.
Botanica Marina, 4: 119-240.
JOHN, D. M. & LAWSON, G. W., 1972. Additions to t h e marine algal flora of Ghana 1 . Nova Hedwigia,
21: 817-841.
KYLIN, F., 1940. Die Phaeophyceenordung Chordariales. Acta Universitatis Lundensis, 36: 1-67.
LAWSON, G. W., 1966. The littoral ecology of West Africa. Oceanography and Marine Biology. Annual
Review, 4: 405-448.
LAWSON, G. W. & PRICE, J. H., 1969. Seaweeds of the western coast of tropical Africa and adjacent
islands: a critical assessment. I. Chlorophyta and Xanthophyta. Botanical Journal of the Linnean
Society, 62: 279-346.
LEMOINE, M., 1928. Les algues calcarie des Canaries: 6580662. A.F.A.S. Congres de la Rochelle.
LEMOINE, M., 1963. Contribution a l’ktude des Mklobkikes de 1’Archipel du Cap Vert. Proceedings of
the International Seaweed Symposium, 4: 234-239.
LEMOINE, P., 1965. Algues calcaires (MPlobkiCes) recueillies par le Professeur Drach (croisikre d e la
Calypso en mer Rouge, 1952). Bulletin de I’Institut Oceanographique de Monaco, 6 4 : 1-20.
118
G. W. L.AWSON AND D. M. JOHN
LEMOINE, M., 1966. Algues calcaires recueillies dans la mer Rouge en particulier dans le Golfe d’Eilat.
Bulletin Sea Fisheries, Research Station, Israel, 42: 3-27.
LEVRING, T., 1939. Uber die Phaeophyceen gattungen Myriogloia Kuck und Haplogloia nov. gen.
Botaniska Notiser, 1939: 40-52.
LEVRING, T., 1969. The vegetation in the sea. In Levring, T., Hoppe, H. A. & 0. J . Schmid, Marine
Algae-A survey of research and utilization. Botanica Marina Handbooks, 1. Hamburgh: Cram, De
Gruyter & Co.
LEWIS, J. R., 1961. The littoral zone on rocky shores-a biological or physical entity? Oikos, 12:
281-301.
MICHANEK, G., 1971. A preliminary appraisal of world seaweed resources. F A 0 Fisheries Circular,
no. 128: ii + 37. Rome: FAO.
MICHANEK, G., 1975. Seaweed resources of the ocean. F A 0 Fisheries Technical Paper, no. 138: v + 127.
Rome: FAO.
NIZAMUDDIN, M., 1970. Phytogeography of th e Fucales and their seasonal growth. Botanica Marina, 8:
131-9.
NORTON, T. A., 1970. Synopsis of biological data on Saccorhiza polyschides. F A 0 Fisheries Synopsis,
no. 83: v + 28. Rome: FAO.
PARKE, M. & DIXON, P. S., 1976. Check-list of British Marine Algae-Third Revision. Journal of the
Marine Biological Association of the United Kingdom, 56: 527-594.
POSTELS, E., 1968. Marine hydrology and biogeography in western Africa. In International Atlas of West
Africa. OAU Scientific, Technical and Research Commission, pls 1-42. Paris.
PRIMO, C., 1953. A contribution t o th e study of the seaweeds of Spanish West Africa. Proceedings of the
International Seaweed Symposium, 1: 23-24.
ROBERTS, M., 1967. Studies on marine algae of the British Isles. 4. Cystoseira baccata (Gmelin)
Silva.British Phycological Bulletin, 3: 367-3 78.
ROBERTS, M., 1970. Studies o n marine algae of the British Isles. 8. Cystoseira tamariscifolia (Hudson)
Papenfuss. British Phycological Journal, 5 : 201-210.
RODRIQUES, J . E. de M., 1960. R e v i s b das algas d e S. T o m i a Principe d o herbario d o Instituto
Botanic0 de Coimbra I-Phaeophyta. Garcia de Orto, 8: 583-595.
SAUVAGEAU, C., 1912. A propos des Cystoseira de Banyuls et GuCthary. Bulletin de la Station
Biologique d’Arcachon, 14: 133-556.
SAUVAGEAU, C., 1913. Sur les FucacCes d u dCtroit d e Gibraltar. Comptes Rendus Hebdomadaires des
Seances d e 1’Academie des Sciences, Skrie, 157: 1539-1540.
SAUVAGEAU, C., 1920. A propos des Cystoseira de Banyuls et d e Guithary. Supplement (1). Bulletin d e
la Station Biologique d’drcachon, 17: 1-51 (1915-1920).
SCHMIDT, 0. C. & GERLOFF, J., 1957. Die marine Vegetation Afrikas in ihren Grundziigen dargestellt.
Willdeno wia, 1: 709-7 56.
SEOANE-CAMBA, J . , 1960. Nota sobre algunas especies de algas d e la costa occidental africana (sur d e
Cab0 Blanco). Znvestigacibn Pesquera, 16: 91-103.
SEOANE-CAMBA, J., 1965. Estudios sobre las algas bentbnicas en la costa sur la Peninsula Iberica (litoral
d e Cadiz). Znvestigacibn Pesquera, 29: 3-216.
SOURIE, R., 1954a. Contribution a I’itude Ccologique des cbtes rocheuses d u Sinigal. Mkmoires de
l’lnstitute Franpaise d ’ d f n q u e Noire, 38: 1-342.
SOURIE, R., 1954b. Principaux types de zonations verticales des algues sur le littoral rocheux d e la
presqu’fle du Cap Vert (zone intercotidale). Rapport et Communications de I’lnternationale Botanique
Congrks 8(17): 151-3.
SOUTHWARD, A. J., 1958. The zonation of plants and animals o n rocky seashores. Biological Reviews,
33: 137-177.
STEENTOFT, M., 1967. A revision of the marine algae of SZo Tome and Principe (Gulf of Guinea).
Journal of the Linnean Society (Botany), 60: 99-146,
STEPHENSON, T. A. & STEPHENSON, A., 1972. Life between tidemarks on rocky shores. San
Francisco: Freeman & Co.
TROCHAIN, J., 1940. Contribution a I’itude d e la vCgCtation du S h i g a l . Memoires de l’lnstitute
Francaise d’Afrique Noire, 2: 1-433.
WOELKERLING, W. J., 1971. Morphology and taxonomy o f t h e Audouinella complex (Rhodophyta) in
southern Australia. Australian Journal of Botany, Suppl. Series, 1 : 1-91.
I