Ascend | JFD-72F | View the Article - Sabinet Reference

Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2012)
DINTERIA NR. 16 - WINDHOEK SW.A. - NOVEMBER 1982
Chemical composition of some Lichen species
occurring in the' N amib Desert,
South West Africa
J. J. Joubert!, P. L. Steyn 2, T. J. Britz 3 and D. C. J. Wessels 4
ABSTRACT
The protein content of three species of lichens from the Namib Desert was determined
by means of the conventional Kjeldahl technique. Of these, Parmelia hottentotta had
the higliest protein content (16,24%), followed by Omphalodium convolutum (14,42%)
and Teloschistes capensis (13,45%)~ Acid hydrolysis of thalli of the three species
yielded fructose, galactose and glucose as well as the amino sugar glucosamine. The
hydrolysate also contained a variety of amino acids.
/
1
2
3
4
A viva, 67 Beatrix Street, 0002 Pretoria.
Department of Microbiology and Plant Pathology, University of Pretoria, 0002 Pretoria.
Department of Microbiology, University of the Orange Free State, 9300 Bloemfontein.
Department of Botany, Umversity of the North, Private Bag X5090, 0700 Pietersburg.
./
33
Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2012)
UITTREKSEL
Die proteininhoud van drie ligeenspesies uit die N amib-woestyn is deur middel van die
konvensionele Kjeldahl-metode bepaal. Van die drie het Parmelia hottentotta die
hoogste proteien-inhoud gehad (16,24%), gevolg deur Omphalodium convolutum
(14,42%) en Teloschistes capensis (13,45%). Suurhidrolise van die drie spesies het
fruktose, galaktose, glukose en die "aminosuiker glukosamien opgelewer. Die hidrolisaat het ook 'n verskeidenheid amino sure bevat.
INTRODUCTION
A considerable amount of work has been published on the chemical composition of
the extracellular products of lichens. The chemistry, structure, properties and distribution of these so-called ~chen substances have been treated in detail by Asahina &
Shibata (1954), Culberson (1969, 1970) and Culberson, Culberson & Johnson (1977).
Several studies have also appeared on the chemistry of carbohydrates, free amino acids
and other intraceUular products. Reference to these products has been made by
Huneck (1973), Mosbach (1973) and Hale (1974).
Huneck & Follmann (1971) reported on the occurrence of lichen substances in Teloschistes capensis (L.f.) Malme (salazinic acid, parietin) and Omphalodium convolutum Hue (norstictic acid, stictic acid, (+) - usnic acid). The findings of these and
other authors regarding the occurrence of lichen products in other species indigenous
to South West Africa are listed by Culberson (1970) and Culberson et al (1977).
Considerable lichen growth occurs in certain parts of the central and northern Namib
Desert. More information on their chemical composition seemed of interest in view
.of their role as primary producers of organic matter in such an arid environment. This
paper represents an effort to determine the total nitrogen content as well as the amino
acid and carbohydrate composition of three lichen species from the Namib .Desert.
MATERIALS AND METHODS
Lichen material
All the lichens used in this investigation were obtained through the courtesy of th~.
Director, SWA Administration, Department of Nature Conservation and Tourism,
and collected by Mr. J. Jankowitz. Parmelia hottentotta Ach. (Plate 1) was f6und
approximately 35 km east of Henties Bay. Omphalodium convolutum (Plate 2) was
collected along the gravel road between Swakopmund anq Windhoek, approximately
15 km from Swakopmund. Teloschistes capensis (Plate 3) :was collected on the gravel
flats approximately 3 km north of Wlotzka's Baken.
\
The lichen material was thoroughly cleaned of adhering soil and rock particles.
\
34
Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2012)
Plate I: Parmelia hOllentOtla Ach.
In its natural surrounding.
(Photo W. Giess )
35
Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2012)
Plale 2: Ompha/odium COllrO/Ulum Hue.
In ilS nalural surrounding.
36
Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2012)
Plate 3: Te/oschisles cilpellsis (L.L) Malme.
In its natural surrounding.
(Photo W. Giess)
37
Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2012)
Amino acid and amino sugar assay
The fragmented thalli were washed in 0,5 M sodium phosphate butTer (pH 7,5) and
lyophilized. Ten mg of thallus material was hydrolyzed in 1 cm 3 6N HCI at 100°C
for 16 h in a sealed ampule. The solution was then evaporated to dryness in a rotary
flask evaporator and finally redissolved in 1 cm 3 distilled water. The pH was adjusted
to pH 8,0 with 5N NaOH. The solution was centrifuged and the clear supernatant
stored at 4°C. the solutions (0,1 cm3) were diluted with 0,9 cm 3 citrate butTer
(pH 2,2) and 0,2 cm 3 of this was used for assay on a Bio-Cal BC-200 automatic,
amino acid analyser. Resins used in the assay were of the Aminex polystyral base type
with a cross-linking of 7,5 to 8,0% divinylbenzene. The assay specifications were as.
follows:
1. Basic amino acids
Column
Resin
Resin height
ButTers
Temperature
25 cm with internal diameter of 0,9 cm
Arninex AS, particle size 11,5-15,5 ~m
14 cm
- pH 5,28; 0,35N in Na ions and 0,2N NaOH
- 50°C
2. Neutral and acidic amino acids
Column
60 cm with internal diameter of 0,9 cm
Resin
- Aminex A6, particle size 15,5-19,5 ~m
Resin height
- 54 cm
ButTers
- A = pH 3,25; 0,2N in Na ions
B = pH 5,25; 0,2N in Na ions and 0,2N NaOH
Temperature
- 50°C
An amino acid calibration mixture supplied by Beckman Instruments was used as
standard. This standard solution contained 1 cm 3 of 0,62N HCI with 2,50 ± 0,004
~mole of each amino acid. One cm 3 of this solution was diluted to five cm 3 and
0,2 cm 3 was applied to the colu~n, giving a final concentration of 0,1 ~mole. Due to
the low solubility of cystine it was only present in half the concentration. The amount
of each amino acid was determined by the width x height method as described in the
manual. During prolonged hydrolysis with 6N HCI, the amino sugars underwent
hydrolytic degradation. No attempt was made to correct for the hydrolytic loss of the
amino sugars or the corresponding increases in ammonia.
Analysis of the cell sugars
A modification of the method of Cato, Cummins and Smith (1970) was used for tl~e'
analysis of the cell sugars. Ten mg amounts of washed thal,li were hydrolyzed in 2 C~3'
of 2N H2S04 for two hours in a boiling water bath. When cooled, the acid walneutralized with solid barium hydroxide to a pH of 7,0. The~recipitate was removed by
centrifugation and the deposit washed with 2 cm 3 of distilled water. The supernatant
was evaporated in a water bath at 60°C. The dry residu~ was dissolved in 0,3 cm 3
distilled water. The solution at this step was clear of any remaining barium hydroxide.
One dimensional ascending thin layer chromatography wa~ performed on silica gel G
38
Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2012)
according to Stahl (Type 60 - Merck). The solvent system ethyl acetate (65 cm 3) and
35 cm 3 isopropanol-water mixture (2:1) was used. (Akhrem & Kuznetsova, 1965).
The chromatograms were run for three hours at 5°C. Spots were visualized by
spraying with acetonic-aniline-phthalate (aniline 2,0 cm 3 ; phthalic acid 3,0 g; acetone
95 cm3 and 5 cm 3 water) followed by heating at !05°C for five minutes. One ul of
either hydrolysate of known standard was applied to the base line of chromatogram.
The relative amounts present have been arbitrarily graded as 3+, 2+, +, (+) or-,
according to the size and intensity of the spot obtained.
Nitrogen Content was determined by means of the conventional Kjeldahl method.
A conversion factor of 6,25 was used for calculating the crude protein content.
RESULTS AND DISCUSSION
The crude protein content of the three investigated species is shown in Table 1. In all
three cases the crude protein content was unexpectedly high and compared favourably
with that of lucerne hay (17,1%) and was much higher than that of veld grass hay
(5,9%) (Van der Merwe, 1970)
According to Huneck (1973) the protein content of lichens varies between 1,6 and
11,4% of their dry weight. Some lichens, notably Peltigera canina growing in the
Himalayas may, however, contain as much as 21% protein (Subramanian &
Ramakrishnan, 1964). The range of amino acids found in the investigated liches was
similar to those found in other plants and micro~organisms, and none of the less
commonly occurring amino acids were detected. (See table 2). The highest
concentration of amino acid found was glutamic acid in the case of P. hottentotta.
There was a notable absence of cystine, hydroxy-proline and ornithine in all three
species. The absence of D-, L- or meso-diaminopimelic acid is not unexpected as this
amino acid has so far only been found in bacterial cell walls. Unfortunately tryptophan
could not be resolved by the method used and no further attemps were made to
determine the tryptophan content of the lichen thalli.
The use of the factor of 6,25 for converting Kjeldahl nitrogen into protein content,
is subject to criticism, because no attempt was made to determine whether the ratio
between nitrogen from protein, free amino acids, nucleic acids or chlorophyll was
approximately the same as that from plant material of known cO,mposition.
The usefulness of a protein depends upon its digestibility as well as its biological
value. The biological value is determined by the number and kinds of amino acids
i present in the molecule: The nearer the food protein approaches the body proteins in
: amino acid make-up, the higher will be the. biological value. (McDonald, Edwards &
j Greenhalgh, 1973). According to data on the essential amino acid composition of
. proteins for n~n-ruminants (NRC, 1973), O. convolutum was low in methionine/
; cystine, lysine, histidine and i-leucine; P. hottentotta was low in histidine, while
T. capensis was low in histidine and phenylalanine/tyrosine. Unfortunately tryptophan, which is, an essential amino acid for non-ruminants, was not assayed. The uses
of lichens by man as an, emergency ration and as part of his daily diet has i?een
39
Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2012)
discussed by Richardson (1977). As the chances are remote that the lichen growth of
the area will be used as a food source by non-ruminant mammals no further consideration was given to this aspect.
In ruminant diets the amino acid composition is of less impo'rtance than the total
protein and carbohydrate content. The use of lichens as a food source by vertebrates
has been summarized by Richardson (1975) and Richardson & Young (1977). It'was
mentioned by Richardson (1975) that lichens preferred by reindeer were not those with
the highest protein content but the ones which contained a high proportion of complex carbohydrates. He also stated that a deer requires the equivalent of about 2 kg
of dry lichen daily. To obtain that amount an animal browses about 12 m2 of lichen
which amounts to approximately 2160 m2 of pasture every 180 days. Because of
the slow growth of lichens a particular lichen range is not ready for regrazing for 2-5
years after modest grazing. This period increases to 10-15 years after intense grazing
(Richardson, 1975).
It seems that the lichen fields of the Namib Desert are utilized by animals (springbuck
in particular) as a supplementary food source, especially during prolonged drought
periods inland (sightings by D.C.J.W.; CoetzeeI, 1978 and Loutit 2 , 1979
personal communications). The existence of such an association will hardly be
surprising in view of the universal occurrence of such relations.
Wessels, Wessels & Holzapfel (1979) reported on the relationship between two lichenfeeding Coleoptera species and Teloschistes capensis in the Namib Desert., The vast
literature that exists on such relationships has been extensively reviewed 'by Gerson
(1973) and Gerson & Seaward (1977). According to Gerson & Seaward (1977) insects, mites and mollusc constitute important components of the terrestrial fauna and
are the main lichen grazers while the Protozoa, Rotifera and Tardigrada 'belong to the
aquatic lichen-feeding fauna. The report of Wessels et al (1979) is unique in the sense
that it is the first report on the existence of such an association between members of
the terrestrial fauna and lichens from an arid region.
As no tests for digestibility were carried out nor the true protein or carbohydrate
content determined, conclusions can not be drawn regarding the usefulness of these
lichen species as a food source for animals. In view of the relationships that exist
between lichens and animals of the Namib Desert, it is intended to pursue this
aspect further, concentrating on insect-lichen relationships as research has already
been completed.
Other low-molecular compounds, such as carbohydrates are reported to be abundant:
in lichens (Aspinall, Hirst& Warburton, 1955; Lindberg, Misiorny & Wachtmeist~r,
1953). The carbohydrates and amino sugars that could be, detected in the three inyi~ti­
gated species are shown in Table 3. No attempt was madelto investigate the occtfrrence
of polyols or polyol glycosides for which lichens are n~ted. Glucose, fructose and
I
I
i
i
I Mr. F. Coetzee; Nature Conservation and Tourism, P.O. Box 51, 9000 Swakopmund.
2 Mrs. B. Loutit; c/o The Senior Game Ranger, Ugabmond, Skeleton <I:oast Park, Private Bag 5001, 9000
I
Swakopmund.
-
40
Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2012)
galactose are known constituents of lichens after chemical hydrolysis. Doubtful
amounts of lactose could only be detected in O. convolutum. GalaCtosamine is a
known constituent of many polysaccharides, yet was not detected in any of the three
specimens analysed. Ribose was included as standiud but contrary to expectations it
was not detected. This can only be explained in-that the concentration may have been
too low to be detected.
No attempt was made to investigate the occurrence of extraceliular lichen substances.
These substances are mostly weak phenolic compounds and their physiological role
has been the subject of considerable speculation. Huneck (1973) and Mosbach (1973)
respectively discussed the nature and biosynthesis of such extracellular substances
while reference to their economic uses and possible ecological role was made by
Richardson (1975) and Vartia (1973).
TABLE I: Crude protein content of three species of Namib Desert Lichens.
% crude protein
Species
14,42
16,24
13,45
Omphalodium convolutum
Parmelia hottentotta
Teloschistes capensis
TABLE 2: Quantitative amino acid analysis of three species of r-/amib Desert Lichens expressed as ~mol
per 10 mg of dried material.
Amino Acid
Alanine ....................
Arginine ....................
Aspartic Acid ................
Cystine ....................
Diaminopimelic Acid ..........
Glutamic Acid ...............
Glycine ....................
Histidine ....................
Hydroxyproline ..............
Isoleucine
................
Leucine ....................
Lysine .....................
Methionine ..................
,Ornithine ...................
! Phenylalanine ................
Proline ......................
.
Serine .....................
Threonine ..................
yypt?phan .................
. Tyrosme ...................
Valine .....................
Ammonia ...................
...
'
I
.-
i
i
=
/
Omphalodium
convolutum
Parmelia
hottentotta
Teloschistes
capensis
1,50
0,25 '
1,50
0,0
0,0
1,50
1,50
0,08
0,0·
0,30
0,75
0,35
0,25
0,0
1,60,
1,40
1,25
1,30
3,15
0,90
3,20
0,0
0,0
4,60
2,95.
0,0
0,0
0,85
2,20
1,66
0,50
0,0
1,45
2,35
2,40
2,15
2,20
0,55
2,35
0,0
0,0
3,75
2,10
0,0
0,0
0,50
1,25
1,10
0,40
0,0
0,0
1,55
1,80
1,45
0,0
0,55
2,60 I
0,90
1,25
4,30
0,0
0,95
3,60
Not assayed
41
Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2012)
TABLE 3: Qualitative amino sugar and carbohydrate analysis of three species of Namib Desert Lichens.
Amino sugars and
carbohydrates
Glucosamine ............... .
Galactosamine .............. .
Monosaccharides
Arabinose .................
Fructose ..................
Glucose ...................
Mannose ..................
Rhamnose .................
Galactose ..................
.
.
.
.
.
.
Omphalodium
convolutum
Parmelia
hottentotta
Teloschistes
capensis
+
+
+
++
+++
++
(+)
+
+
Disaccharides
Lactose ................... .
Maltose ................... .
(+)
+ present in small amounts; + + present in intermediate amounts; + + + present in appreciable amounts;
(+) doubtful; - absent.
SUMMARY
The thalli of three lichen species collected from the Namib Desert (Omphalodium
convolutum, Parmelia hottentotta and Teloschistes capensis) were analyse,d for their
crude protein content, amino acid composition of the proteins and the sugar composition of the carbohydrates.
The crude protein content, calculated from the total nitrogen content as determined
by means of the conventional Kjeldahl method, was found to be unexpectedly high in
all three cases (14,42% for O. convolutum, 16,24% for P. hottentotta and 13,45%
for the T. capensis.) The amino acid composition of the thallus proteins was determined by means of an automatic amino acid analyser after acid hydrolysis. The range
of amino acids found was similar to those found in higher plants and micro-organisms,
and none of the less commonly occurring amino acids was d~tected. The highest concentration of amino acid found was that of glutamate in P. hottento tta. Ther~ was
a notable absence in all three cases of cystine, hydroxy-proline and ornithine. The
digestibility of the thalli by ruminants as well as non-ruminants was not determined
accordingly, no conclusions could be drawn regarding the usefulness of the lichen
thalli as a food source.
Carbohydrates were analysed. by acid hydrolysis and thin layer chromatography.
Fructose and glucosamine were detected in all three species, the former in appresJable
amounts. Glucose was detected in only two of the three bases, whereas galactose and
\
.
lactose were found in only one species.
;
Reference has also been made to the role of lichens
as
.
the area.
Plates of the three lichen species are presented.
42
afood source for animals in
I
Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2012)
ACKNOWLEDGEMENTS
The authors are indebted to the Director, SWA Administration Department of Nature
Conservation and Tourism for supplying the material and to their respective institutions for financial assistance.
REFERENCES
AKHREM, A.A. & KUZNETSOVA, A.I., 1965. Thin layer chromatography. Israel program for
Scientific translations. Jerusalem.
ASAHlNA, Y. & SHIBATA, S., 1954. Chemistry of Lichen substances. Tokyo: Japan Society for
the promotion of Science.
ASPINALL, G.O., HIRST, E.L. & WARBURTON, M., 1955. The alkali-soluble polysaccharides
of the lichen Cladonia campestris. J. Chem. Soc. 1955: 651-655.
CATO, E.P., CUMMINS, C.S. & SMITH, L.D.S., 1970. Clostridium limosum Andre in Prevot
1948, 165. Amended description and pathogenic characteristics. Int. J. Syst. Bacteriol. 20:
305-316.
CULBERSON, C.F., 1969. Chemical and Botanical Guide 10 Lichen Products. Chapel Hill:'University
of North Carolina Press.
CULBERSON, C.F., 1970. Supplement to "Chemical and Botanical Guide to Lichen Products".
Bryologist 73, 77-377.
CULBERSON, C.F., CULBERSON, W.L. & JOHNSON, A., 1977. Second supplement to "Chemical ilnd Botanical Guide to Lichen Products". Missouri Botanical Garden, St. Louis: The American
Bryological and Lichenological Society.
GERSON,U., 1973. Lichen-arthropod associations. Lichenologist 5, 434-443.
GERSON, U. & SEAWARD, M.R.D., 1977. Lichen-invertebrate associations. Ch. 4 in: Lichen
Ecology. Edited by M.R.D. Seaward, London, New York and San Francisco: Academic Press.
HALE, M.E., 1961. Lichen Handbook. Washington: Smithsonian Institution.
HALE, M.E., 1974. The Biology of Lichens 2nd edition. London: Edward Arnold.
HUNECK, S., '1973. Nature of lichen substances. Ch. 15 in: The Lichens. Edited by V. Ahmadjian
& M.E. Hale, New York and London: Academic Press.
HUNECK, S. & FOLLMANN, G., 1971. Mitteilungen iiber Flechteninhaltsstoffe LXXXVII Neue
Flechtenanalysen. Willdenowia 6. 273-282.
LINDBERG, c., MISIORNY, A. & W ACHTMEISTER, C.A., 1953. Studies on the 'chemistry of
lichens. Acta Chem. Scand. 7: 591-595.
McDONALD, P., EDWARDS, R.A. & GREENHALGH, J.F.D., 1973. Animal nutrition., 2nd edition. London and New York: Longman.
MOSBACH, K., 1973. Biosynthesis of lichen substances. Ch. 16 in: The Lichens. Edited by
V. Ahmadjian &' M.E. Hale, New York and London: Academic Press.
RICHARDSON, D.H.S., 1975. The Vanishing Lichens. Their History, Biology and Importance.
Newton, Abbot, London and Vancouver: David & Charles.
RICHARDSON, D.H.S. & YOUNG" C.M., 1977. Lichens and Vertebrates. Ch. 5 in: Lichen
Ecology. Edited by M.R.D. Seaward, London, New York and San Francisco: Academic Press.
SABRAMANIAN, S.S. & RAMAKRISHNAN, S., 1964. Amino acids of Peltigera canina. Curro
Sci. 33: 522.
VAN DER MERWE, F.J., 1970. Dierevoeding. Stellenbosch: Kosmo Uitgewery Edms. Beperk.
,VARTIA, K.O., 1973. Antibiotics in lichens. Ch. 17 in: The Lichens. Edited by V. Ahmadjian &
r M.E. Hale, New York and London: Academic Press.
WATT, J.M. & BREYER-BRANDWI1K, H.G., 1962. Medicinal and Poisonous Plants of Southern
and Eastern Africa. London and Edinburgh: E. and S. Livingstone.
WESSELS, D.C.J., WESSELS, L.A. & HOLZAPFEL, W.H. 1979. Preliminary report on lichenfeeding Coleoptera occurring on Teloschistes capensis in the Namib Desert, South West Africa.
Bryologist 82, 270--'-273.
43
Reproduced by Sabinet Gateway under licence granted by the Publisher (dated 2012)
INHALT DER BISHER ERSCHIENENEN AUSGABEN:
Nummer I: (November 1968,51 S .. I Karte, 16 Fotos)
Giess, W., Kurt Dinter
-, A short report on the vegetation of the Namib coastal area from Swakopmund to Cape Frio.
-, Die Gattung Rhigozum und ihre Arten in Sjjdwestafrika.
Nummer 2: (September 1968, 36 S., I Karte, 21 Abb., 3 Fotos)
Kers, L. E., On Sphaeranlhus similis Kers sp. nov., S. epigaeus Schinz and S. sluhlmannii O. HotTm. (Compositae), with notes
on their distribution, branching and growth-habit.
Smook, L., Some observations on Lindernia intrepidus (Dinter) Oberm. (Chamaegigas intrepidus Dinter).
Giess, W., Die Verbreitung von Lindernia inlrepidus (Dinter) Oberm. in Sudwestafrika.
--, Prodromus einer Flora von Sudwestafrika.
Nummer 3: November 1969,56 S., I Karte, 17 Fotos)
Giess, W" Welwitschia mirabilis Hook. fII.
Rust. H. J .. Thc distribution of Welwilschia mirabilis (Buchbesprechung).
Nummer 4: (November 1971, 114 S., mehrfarbige Faltkarte. 70 Fotos)
Giess, W.o Eine yorlaufige Vegetationskarte von Sjjdwestafrika mit dreisprachiger Einfjjhrung und Erlauterung der hauptsachlichsten
Vcgetationsgruppen und -typen durch Text und Bild. 2. Auflage 1977.
Nummer 5: (Juli 1970, 64 S., I Karte, 22 Fotos und Abb.)
Nordenstam, 8., Notes on the Flora and Vegetation of Etosha Pan, South West Africa.
Giess, W., Ejn Beitrag zur Flora des Etoscha-Nationalparks.
-, Moringa ovalifolia, die boom van die sprokieswoud.
-, Die Verbreitung von Moringa ovalifolia Dinter & Berger in Sjjdwestafrika,
Nummer 6: (August 1972, 41 S., 3 Karten, 9 Abb.)
Leser, H., Geookologische Verhaltnisse der Pflanzengesellschaften in den Savannen des Sandveldes urn den Schwarzen Nossob und
urn Epukiro (6stliches Siidwestafrika, westliche Kalahari). (VergritTen)
Nummer 7: (Oktober 1972, 19 S., 2 Karten, 5 Fotos und Abb.)
Gaff, D. F., Drought resistance in Welwitschia mirabilis Hook. fil.
Herre, H., Erinnerungen an Professor Kurt Dinter.
Giess, W., Der Botanische Garten auf Farm Lichtenstein bei Windhoek im Jahre 1922.
Beitrage 'aus dem Leserkreis: Volkmann, H. J., Welwitschia mirabilis; Steyn, A. J., Welwilschia mirabilis; Marwitz, K..
Rhigozum brevispinosum; Moisel, L., Moringa ovalifolia; Woortman, G" Aloe lilloralis.
Nummer 8: (Novembcr 1972, 55 S., 26 Fotos und Abb.)
Rutherford, M.e., Notes on the flora and Vegetation of the Omuverume Plateau-Mountain, Waterberg, South West Africa.
Nummer 9: (April 1973,31 S., 17 Fotos und Abb.)
Coetzee, H., Van der SchijtT, H. P., & Steyn, E., External mprphology of the species of the South African Velloziaceae
including a key based on external morphological characteristics. - Uitwendige morfologie van die spesies van
Suid-Afrika en 'n sleutel gebaseer op uitwendige morfologiese kenmerke.
Van der Walt, J. J, A .. A new species of Commophora from the Kaokoveld (South West Africa).
Velloziac~ae
in
Nummer 10: (Juni 1974,44 S., 25 Fotos und Abb.)
Giess, W., Zwei Fahrten zur Jensenobolrya lossowiana Here.
Robinson, E. R. & Giess. W., Report on the plants noted in the course of a trip from Ljjderitz Bay to Spencer .Bay. January
10-12, 1974.
Gicss, W., Beobachtungen zur Sudwester Flora: Welche Pflanzc is das? (Hoodia gordon;; (Masson) Sweet X Trichocaulon
pedicel/alum Schinz); Siapelia schinzii Berger & Schlechter X Siapelia kwebensis N.E.Br.; Beobachtung zu Aloe dicholoma
Masson; Zur Verbreitung von Eragrostis sabinae Launen; Ximenia cajJra Sonder var. nalalensis Sonder (Olacaceae) aus
Ovambo.
Nummer II: (Dezember 1974, 67 S., 8 Abb., I Karte)
Nordenstam, B.. The Flora of the Brandberg.
Nummer 12: (Marz 1976, 35 S., 24 Fotos, 4 Karten)
Leach. L. C, Euphoria (Tetracanthae) in Angola and northern. Kaokoland.
Nummer 13: (Juli 1977, 24 S., 7 Abb.)
Bruckner, V.. Ubcr cinige lnhaltsstoffe der Wolfsmilchgewach~e unter besonderer Berucksichtigung der Krebsverstarker.
Nummer 14: (April 1978, 20 S., 9 Fotos und Abb., 2 Karten)
I
PutT. Ch., Zur Biologie von Myrolhamnus J7abel/ifolius Wclw. (Myrothamnaceae).
1
i
I
Nummer 15: (Januar 1981, 72 S., 3 Karten, I Tafcl und 73 Fotos)
1
Moisel, A. and Moll, E. J., A Braun-Blanquet Survey of the Vegetation of the Welwitschia Plain.
Giess, W., Die in der Zentralen Namib von Sudwcstafrika/N amibia festgestellten Pflarizenarten und ihre Biotope.
-I .
44
Download PDF