Bothalia 17,2: 213-227 (1987)
Preliminary floristic analysis of the major biomes in southern
Africa
G. E. GIBBS R U SSELL *
Keywords: biomes, Desert, Fynbos, Grassland, Karoo, Nama-Karoo, Savanna, species diversity, Succulent Karoo
ABSTRAC T
Over 24 000 plant taxa are known to occur in the southern African flora, which is extraordinarily rich on a
species/area basis. Lists of species and infraspecific taxa recorded for the six major biomes, Fynbos, Savanna,
Grassland, Nama-Karoo, Succulent Karoo and Desert, were obtained from the PRECIS specimen database.
These lists were analysed by numbers of unique and shared species and infraspecific taxa. by differential occur­
rence and life forms of large genera, and by differential occurrence of families. Each biome is floristically distinct
except Nama-Karoo. The biomes form two main groupings, those with winter rainfall and those with summer
rainfall. Succulent Karoo is most similar to Fynbos and Nama-Karoo is most similar to Savanna.
UITTREKSEL
Dit is bekend dat meer as 24 000 planttaksons in die suider-Afrikaanse flora voorkom, wat op "n spesies/areagrondslag buitengewoon ryk is. Lyste van spesies en infraspesifieke taksons van die ses hoofbiome, Fynbos,
Savanne, Grasveld, Nama-Karoo, Sukkulente Karoo en W oestyn, is vanaf die PRECIS-eksemplaardatabasis
verkry. Hierdie lyste is ontleed in terme van unieke en gemeenskaplike spesies en infraspesifieke taksons, differensiële voorkoms en lewensvorme van groot genusse, en die differensiële voorkoms van families. Elke bioom
behalwe Nama-Karoo, is floristies kenmerkend. Die biome vorm twee hoofgroeperings, dié met winterreënval en
dié met somerreënval. Sukkulente Karoo toon die meeste ooreenkoms met Fynbos en Nama-Karoo toon die
m eeste ooreenkoms met Savanne.
CONTENTS
INTRODUCTION
Introduction ...................................................................213
M e th o d s ..........................................................................214
Results and discussion...................................................216
A rea, taxa and specim ens....................................... 216
Com parison of biom es by num bers of species
and infraspecific ta x a ....................................... 216
Sorenson's coefficients of sim ilarity .....................216
P erc en tag eso fu n iq u e an d sh ared tax a.................217
Com parison of biomes by im portant families
and large g e n e ra ................................................217
Differential occurrence of im portant families 217
C entres of diversity of large g e n e ra .................. 219
Life forms and centres of diversity of large
g e n e ra .............................................................. 220
Floristic characteristics and relationships of
the biomes
F ynbos.........................................................................221
S a v a n n a ......................................................................221
G ra ssla n d ...................................................................221
N am a-K aro o ............................................................. 221
Succulent K a ro o ....................................................... 221
D e s e r t.........................................................................221
R elatio n sh ip s........................................................... 222
C onclusions....................................................................222
A cknow ledgem ents..................................................... 222
R eferen ces..................................................................... 222
A ppendix 1 ....................................................................223
Appendix 2 ....................................................................225
Appendix 3 ....................................................................226
A ppendix 4 ....................................................................227
The southern African flora is extrem ely speciesrich in term s of species/area ratios, with 0,0081
species/km 2 overall (Figure 1). This value is higher
than those recorded for humid tropical floras such as
Brazil (0,0044) and Asia (0,0041) (Gibbs Russell
1985b). The winter rainfall Cape Floral Kingdom is
well known to be extrem ely species-rich (G oldblatt
1978). H owever, even when the Cape flora is ex­
cluded from calculation, the species/area ratio for
the rest of the southern African flora (0,0061) is still
considerably higher than that of the humid tropics,
and nearly twice that of Australia (0,0032), which
also includes both tropical and tem perate areas.
* Botanical Research Institute, Private Bag X101, Pretoria 0001.
These species/area ratios indicate in a superficial
way that the rem arkable species richness of the
southern African flora is not restricted to the Cape
Floral Kingdom. The aim of this study is to investi­
gate the floristic richness of the m ajor biomes and to
explore floristic relationships between these biomes
using distribution data for families, genera and
species.
A t the present tim e, the PRECIS (P retoria N a­
tional H erbarium Com puterized Inform ation Sys­
tem ) specimen database is by far the most com pre­
hensive source of inform ation on the distribution of
plant taxa in southern Africa. Although PREC IS has
certain limitations (see M ethods), this prelim inary
study forms a base against which more detailed stu­
dies of particular biomes can be put in context, and
which will allow the generation of hypotheses to
guide future studies. A re-evaluation should be done
when more com plete checklists, based on co-opera­
tive herbarium studies and intensive field work, have
been compiled for all the biomes.
214
Bothalia 17,2 (1987)
EUROPE0,0011
E . ‘ NO. AMERICA
0 ,0 0 14
/
W. TR O P. AFRICA
0 ,0 0 16
SUDAN l A
0 ,0 0 13
/
V ^ - l j R O P . AFR IC A ,
d O ,0015
B R A ZIL
0 ,0 0 4 7
STHN. AFRICA I
0 ,0 0 8 1 \
^
{/
AU STRALIA
0,0032
STHN_ AFR1CA
E X C L .FY N B O S
0 ,0 0 6 1
FIGURE 1. — Species/area ratios
for large regions. The num­
ber of species and areas in
km2 for each region follow
Gibbs Russell (1985b).
ite map showed six m ajor regions that were recog­
nized as entities, even though none of the studies
agreed on exact boundaries. Elimination of all areas
of disagreem ent, and of areas smaller than a quarter
degree, yielded the regions accepted as the core bi­
omes for this investigation (Figure 2). Im portant en­
vironm ental characteristics of the core biomes are
shown in Table 1.
M ETHODS
This study is based on checklists compiled from
PRECIS for quarter degree latitude and longitude
grids representing the m ajor biomes for southern
Africa. The biomes adopted were determ ined by
superimposing five recent treatm ents of southern
African vegetation using floristic, structural and en­
vironm ental criteria (W erger 1978; Scheepers 1982
based on Acocks 1975; W hite 1983; Huntley 1984;
R utherford & Westfall 1986). The resulting compos-
The lack of agreem ent between the treatm ents
occurred at three levels; 1, exact boundaries at quar­
■ FYNBOS
• SAVANNA
o GRASSLAND
a
t
o
10 0
0
km.........................
10 0 20 0
i
3 0 0 40 0
0 0 60 0 700 800 .
I__I_5____l
'______
FIGURE 2. — Quarter degree grids searched in PRECIS for each biome.
NAMA-KAR00
SUCCULENT KAROO
D ES ER T
Bothalia 17,2 (1987)
215
TABLE 1.— Characteristics o f the biomes
Biome
Rainfall amount*
Rainfall season*
Dominant life forms*
Structural characteristics
Fynbos
Mesic
(2 1 0 -3 000 mm)
Winter
Chamaephytes
Phanerophytes
Cryptophytes
Evergreen sclerophyllous heathland and
shru bland t
Savanna
Mesic
(above 235 mm)
Summer
Hemicryptophytes
Phanerophytes
Wooded C4 grasslands^
Grassland
Mesic
(4 0 0 - 2 000 mm)
Summer
Hemicryptophytes
Grassland, woody plants absent or raret
Nama-Karoo
Arid
(1 0 0 -5 2 0 mm)
Summer
(to all year)
Chamaephytes
Hemicryptophytes
Dwarf and low open shrublandst
Succulent Karoo
Arid
( 2 0 - 2 9 0 mm)
Winter
(to all year)
Chamaephytes
Dwarf and low open succulent shrublandst
Desert
Arid
(1 3 - 7 0 mm)
Summer
Therophytes
Ephemeral, with many annuals
* Rutherford & Westfall (1986)
t Huntley (1974)
ter degree scale; 2, areas of transition between karroid and savanna regions; and 3, areas of compli­
cated vegetation relationships, such as the eastern
Transvaal, Natal and the eastern Cape. The two
‘karroid' biom es accepted here were recognized at
the highest level of classification only by R utherford
& W estfall (1986), on grounds of differences in
dom inant plant life form and environm ental condi­
tions. Their Succulent K aroo Biome roughly coin­
cided with the W estern Cape Dom ain of the KarooNamib Region defined by W erger (1978) at a sec­
ondary level of classification on phytochorological
grounds. The other three vegetation studies treated
the entire karroid vegetation as a single entity at the
highest level. In this investigation. Succulent Karoo
was separated from N am a-K aroo, and a secondary
aim of the study was to examine the floristic relation­
ship betw een them .
Besides the six core biomes adopted for this study,
all the treatm ents recognized the high altitude vege­
tation of the D rakensberg, and the forests of the
southern C ape. H ow ever, these small irregularly
shaped areas were not accessible to com puter search
at the scale of q uarter degree grid reference, and
could therefore not be included.
The PR EC IS specimen database records label in­
form ation for ± 610 000 specimens in the National
H erbarium (P R E ). The overall operation and imple­
m entation of PR EC IS have been reported several
times (G ibbs Russell & Gonsalves 1984; Gibbs Rus­
sell 1985a). M ore recently, new program ming has
allowed com pilation from the database of checklists
of plant species and infraspecific taxa from any com­
bination of q u arter degree grids. Several special pro­
gramm es were w ritten to com pare the checklists by
providing lists of unique taxa, lists of shared taxa,
and a m atrix of all taxa with the biomes from which
they were recorded.
The total num bers of unique and shared taxa, ob­
tained by employing these program m es, were used
to calculate Sorenson’s (1948) coefficients of similar­
ity, and percentages of unique taxa and taxa shared
betw een biom es. The ranking of families for each
biom e, the identification of widespread taxa, and the
determ ination of centres of diversity for ia r g e ’ gen­
era with 10 or m ore species and infraspecific taxa
were obtained by manual searches of printout. A
biom e was considered to be a centre of diversity for
a genus if it contained 50% or more of the taxa re­
ported for the genus. In a few cases, slightly less than
half (to 45% ) was accepted in biomes of low collect­
ing intensity. Life forms follow the definitions of
R aunkiaer (1934) as stated by R utherford & W est­
fall (1986), but with the inclusion of ‘Succulent’, and
were determ ined from Dyer (1975, 1976) and h er­
barium specimens. At all stages of w ork, doubtful
records encountered on PRECIS listings were
checked in PRE.
An inherent weakness in the m ethod used is the
uneven collecting intensity for the different biomes.
Gibbs Russell et al. (1984) showed that the collecting
intensity represented in PRECIS for the eastern and
southern mesic areas is far higher than for the west­
ern arid areas. Therefore, the checklists used here
undoubtedly differ in com pleteness, and it must be
em phasized that these results are preliminary. Table
2 illustrates the differences in collecting intensity b e­
tween the biomes by comparing the specim ens and
the taxa per km 2 as well as the specimens per taxon
recorded in PR EC IS for each biome. A lthough Fyn­
bos, and to a lesser degree G rassland, appear to be
better collected than the other biomes on a speci­
m ens/km 2 or taxa/km 2 basis, Savanna in fact exhibits
m ore ‘rep eat’ collections than either. H ow ever, it is
apparent that mesic Fynbos, Savanna and Grassland
are better collected than arid N am a-K aroo, Succu­
lent K aroo and D esert.
PR EC IS is known to have errors in about 7% of
specimen identifications and quarter degree grid re­
ferences. Until these errors can be corrected, an
ongoing process in system m anagem ent, results must
be used with discretion. In this study, identifications
directly from PR EC IS are used only at the level of
family and genus, while at the level of species and
infraspecific taxa, only total num bers, and not iden­
tifications, are used unless the records were checked
216
Bothalia 17,2 (1987)
TABLE 2 .— Collecting intensity reported from PRECIS for each biome. Area was determined from the number o f quarter degree
grids searched (and ‘average’ quarter degree covers 666 km2)
Fynbos
Savanna
Grassland
Nama-Karoo
Succulent Karoo
Desert
No. specimens
No. taxa
Area (km2)
Specimens/km2
Tax a/km2
Specimens/taxon
52650
50460
27 685
7 685
6 484
1 334
7316
5 788
3 788
2147
2125
497
36 628
632034
111888
198468
50616
41 292
1,36
0,08
0,25
0,04
0,13
0,03
0,19
0,01
0,03
0,01
0,04
0,01
7,2
8,7
7,3
3,6
3,1
2,7
in PR E. For the same reason, distribution is given
only at biome level, and not to individual quarter
degree grids.
Despite the limitations imposed by differences in
collecting intensity and by the accuracy of individual
PRECIS records, at the present time PRECIS is the
most reliable and com plete source of information
about the distribution of taxa throughout the south­
ern African flora. Publication of these preliminary
results is therefore considered worthwhile.
T hroughout the study, the num ber of species and
infraspecific taxa, rather than species alone, were
used in com parisons because of taxonomic uncer­
tainty about the correct level of treatm ent for many
of these entities, as explained in detail in Gibbs Rus­
sell (1985b). For the sake of brevity, the term ‘taxa’
in this context is used in place of the longer phrase
‘species and infraspecific taxa’.
RESULTS A N D DISCUSSION
Area, taxa and specimens
The area, taxa and specimens covered in this study
are summarized in Table 3. The five recent vegeta­
tion treatm ents used to determ ine the biomes for
this study agreed on about 40% of the total area of
southern Africa at a scale available for com puter
search. A bout 60% of all southern African taxa re­
presented in PREC IS were reported from the area
designated. C ertain taxa were not included in the
study for the following reasons: 1, they are known
only outside the areas of the core biomes; 2, they are
not represented in PREC IS; or 3, they are repre­
sented in PREC IS, but the distribution is not re­
corded as a quarter degree grid. Only about 25% of
the specimens in PREC IS are reported in the study.
This low figure results from the uneven collecting
intensity in the National H erbarium m entioned
above.
TABLE 3 .— Total size o f sample reported for all biomes
Number o f specimens
Out o f 6 1 0 0 0 0 in PRECIS
Out o f ±2 0 0 0 0 0 0 in southern African herbaria
Number o f taxa
Out o f 24 000 in southern Africa
Area covered (1 6 1 1 quarter degree grids
@666 km2 per quarter degree)
Out o f 2 573 000 km2 for southern Africa
146 298
24%
7%
14 391
60%
1 072 926 km2
42%
Comparison o f biomes by numbers o f species and
infraspecific taxa
Widely differing numbers of taxa have been re­
corded for the six biomes, and the differences in
taxon num bers are not related to the area sampled
(Table 2). Fynbos has the most taxa although it is the
smallest in area. Savanna, which covers by far the
largest area, has about 1 500 fewer taxa than Fynbos.
Similarly, Grassland has about 1 700 more taxa than
N am a-K aroo, although Nama-Karoo covers about
twice the area of Grassland. Nama-Karoo and Suc­
culent Karoo have similar numbers of taxa, but
N am a-Karoo covers about four times the area of
Succulent Karoo. The num ber of taxa recorded for
Desert is extrem ely low even though its area is
slightly larger than that of Fynbos.
The checklists for each biome were com pared
both by Sorenson’s (1948) coefficient of similarity,
and by percentage comparisons within each biome.
Sorenson’s coefficients give com parable values for
checklists of different length. Low Sorenson’s coef­
ficients signify low similarity between lists of taxa,
while higher values show a greater similarity. The
percentage comparisons show the proportion of taxa
within each biome that are unique and that are
shared with other biomes.
Sorenson’s coefficients of similarity
The Sorenson’s coefficients of similarity between
the six m ajor biomes are shown in Figure 3. The
values for the coefficients are generally low (30 or
less), indicating that each biome has its own flora
which is quite distinct from that of the others. The
exception is the coefficient between Savanna and
G rassland, which is considerably higher than any
other.
For Savanna, the highest Sorenson’s coefficients
occur with Grassland and with Nam a-Karoo, and the
values are low (less than 20) for the other biomes.
G rassland, which has the strongest similarity to
Savanna, has very low Sorenson’s coefficients with
Desert and with Succulent Karoo, and somewhat
higher values with Fynbos and Nama-Karoo. Desert
has very low values with all biomes except NamaKaroo. Fynbos has low Sorenson’s coefficients with
all biomes except Succulent Karoo. Succulent Karoo
and N am a-K aroo show opposite relationships. Ex­
cluding the Sorenson’s coefficient between the two
‘karroid’ biom es, Succulent Karoo has its highest
value with Fynbos, and very low values with D esert,
217
Bothalia 17,2 (1987)
The percentage of taxa shared between the bi­
om es amplifies the relationships shown by the So­
renson’s coefficients. The few apparent contradic­
tions result from com paring taxon lists of very dif­
ferent length: where one list is long and the other
short, the percentage of shared taxa differs m arkedly
from the Sorenson’s values.
FIG URE 3. — Number of taxa and Sorenson’s coefficients of
similarity for the biomes. The number in each large circle is
the number of species and infraspecific taxa reported for
the biome. The number in each small circle is the Soren­
son's coefficient of similarity between pairs of biomes.
Savanna and G rassland, whereas Nama-Karoo has
its highest value with Savanna, high values with D e­
sert and G rassland, and a low value with Fynbos.
Percentages of unique and shared taxa
The percentages of taxa unique to each biome and
shared betw een biom es are shown in Figure 4. The
biomes vary greatly in percentages of unique taxa.
Fynbos has the highest percentage (which is consist­
ent with a value of 68% given by Bond & Goldblatt
(1984)), and Savanna is also well above the others.
Grassland and Succulent Karoo are similar, and D e­
sert and N am a-K aroo have similar and very low per­
centages of unique taxa.
The close floristic relationships between Savanna
and Grassland and Savanna and Nam a-K aroo showr
by the Sorenson’s coefficients are borne out by the
high percentage of Grassland and N am a-K aroo taxi
that is shared with Savanna. Savanna itself shares
m ost taxa with G rassland, shares the same percent­
age of its taxa with Nam a-Karoo as with Fynbos, and
shares a very low percentage of its taxa with Suc­
culent K aroo and D esert. Grassland shares a very
high percentage of its taxa with Savanna, and is simi­
lar to Savanna in that its lowest percentage of shared
taxa is with Succulent Karoo and D esert, but G rass­
land shares a considerably higher percentage of taxa
with Fynbos than with Nama-Karoo. D esert, which
because of its small flora shows very low Sorenson’s
values with all biomes except N am a-K aroo, shares
about the same very high percentage of its taxa with
Savanna as with Nam a-Karoo. Desert has a very low
percentage of unique taxa, and shares m ore than
20% of its taxa with Grassland, with Succulent Ka­
roo and with Fynbos. In contrast, Fynbos, which has
a high percentage of unique taxa, does not share
m ore than 20% of its taxa with any other biom e. The
close relationships of Succulent Karoo to Fynbos
and of N am a-K aroo to Savanna, already indicated
by Sorenson’s coefficients, are borne out by the high
percentage of Succulent Karoo taxa shared with
Fynbos, and the high percentage of N am a-K aroo
taxa shared with Savanna. Both of the ‘karroid’ bi­
om es share the lowest percentage of taxa with D e­
sert and an interm ediate percentage with G rassland.
Comparison o f biomes by important fam ilies and
large genera
D ifferential occurrence of im portant families
Forty-six families comprise 1% or m ore of the
taxa in at least one biome. In each biom e there are
betw een 22 and 28 families that com prise 1% or
m ore of the taxa, and that together account for be­
tween 55 and 60% of the total num ber of taxa. Each
of these families can be used to distinguish and/or
link the biom es (Table 4).
FIG URE 4. — Number and percentage o f species and infraspe­
cific taxa unique to and shared between biomes. In each
large circle, the upper number is the number of unique
taxa, the lower number is the total number of taxa for the
biome, and the percentage is the percentage of taxa unique
for the biome. The number in each small circle is the per­
centage of taxa shared between pairs o f biomes, and the
number on the line connecting a pair is the Sorenson’s
coefficient of similarity.
In order to com pare the biomes in this way, these
im portant families are ranked for every biom e by
num ber of taxa from largest (rank of 1) to smallest
(rank of 22 to 28). Ranking is necessary for com ­
parison at family level because the biomes differ so
greatly in num ber of taxa. A family well represented
in a species-poor biome may in fact have fewer taxa
in that biome than the same family has in a biome
with a rich flora, even though the family is a negligi­
ble com ponent of the more species-rich biome
(G ibbs Russell 1975, 1985b). The families are
ranked in three groups in the discussion: the largest
families (1-3 in bold type in Table 4); the next rank
(4-10 in italics in Table 4); and the lowest rank (from
218
Bothalia 17,2 (1987)
11 onwards in rom an type in Table 4). The biomes
are characterized by the presence, absence or differ­
ence in rank of certain large families, and the occur­
rence of some families can be linked to simple en­
vironm ental param eters characteristic of certain
com binations of biomes.
The seven plant families that comprise 1% or
m ore of the taxa in all of the biomes are shown in
Table 4a. Three families, A steraceae, Poaceae and
Fabaceae are the three largest in all biomes (with the
exception of Poaceae in Succulent Karoo and Fyn­
bos), and either A steraceae or Poaceae is the largest
family in all biomes. Asteraceae and not Poaceae is
the largest family in Grassland.
The six biomes are briefly discussed in turn below:
Fynbos (Table 4b) is distinguished by eight fami­
lies that are im portant in no other biome. Of these,
Ericaceae is one of the three largest families, and
TABLE 4 .— Families represented by more than 1% o f the total number o f taxa in any one of the biomes. Sv, Savanna; G, Grassland;
D, Desert; N-K, Nama-Karoo; SK, Succulent Karoo; F, Fynbos. The number in the matrix is the rank according to number
o f taxa in the family in a given biome, with ‘1’ signifying the largest family in the biome
Sv
G
D
N-K SK
3
1
2
5
10
6
8
1
2
3
4
6
5
12
2
1
3
10
7
12
11
1
2
3
4
5
13
9
1
4
3
5
6
20
19
1
5
2
7
12
9
24
4 b. Families that distinguish Fynbos
3
8
10
14
15
20
22
28
High rank of:
Proteaceae
9
10
7
6
13
7
10
5
17
6
15
6
12
Presence o f :
Verbenaceae
21
High rank of:
Rubiaceae
4
Absence of:
Mesembryanthemaceae
13
8
8
7
13
14
11
11
8
9
20
14
4
16
15
11
7
14
8
27
23
4e. Families that distinguish Nama-Karoo
No families form more than 1% o f flora only in Nama-Karoo.
No families have high rank only in Nama-Karoo.
No families are absent only from Nama-Karoo.
4f. Families that distinguish Succulent Karoo
High rank of:
Iridaceae
Crassulaceae
Geraniaceae
Presence of:
Pedaliaceae
Burseraceae
F
17
20
High rank of:
Chenopodiaceae
Capparaceae
Absence of:
Iridaceae
17
Presence of:
Acanthaceae
Malvaceae
Lamiaceae
Cucurbitaceae
Amaranthaceae
Rubiaceae
Convolvulaceae
Anacardiaceae
Solanaceae
Capparaceae
Boraginaceae
5
9
17
15
24
14
10
7
12
11
19
18
4
13
20
19
17
9
6
21
22
16
11
15
20
22
19
9
18
6
19
20
22
21
24
23
4i. Families that link winter rainfall biomes
Low rank of:
Poaceae
Euphorbiaceae
11
Id. Families that distinguish Grassland
Absence o f :
Sterculiaceae
Aizoaceae
N-K SK
Presence of:
Proteaceae
Oxalidaceae
Campanulaceae
1c. Families that distinguish Savanna
High rank of:
Orchidaceae
Lamiaceae
D
4h. Families that link summer rainfall biomes
Presence of:
Ericaceae
Restionaceae
Rutaceae
Polygalaceae
Thymelaeaceae
Rhamnaceae
Rosaceae
Lobeliaceae
Absence or low rank of:
Asclepiadaceae
Scrophulariaceae
G
4g. Families that distinguish Desert
4a. Families comprising more than 1% o f the total number o f
taxa in all biomes
Asteraceae
Poaceae
Fabaceae
Liliaceae
Scrophulariaceae
Cyperaceae
Euphorbiaceae
Sv
F
10
14
23
14
12
16
2
9
10
4
19
16
1 2
8 12
1 2
11
9
17
11
21
6
21
18
4
19
5
24
4j. Families that link arid biomes
Presence of:
Chenopodiaceae
Zygophyllaceae
High rank o f :
Aizoaceae
Mesembryanthemaceae
15
13
5
15
15
17
18
22
4
8
7
8
8
7
23
13
4k. Families that link Grassland and/or Nama-Karoo to Succulent
Karoo and/or Fynbos
Presence of:
Crassulaceae
Brassicaceae
Selaginaceae
Geraniaceae
Amaryllidaceae
Apiaceae
High rank of:
Iridaceae
Orchidaceae
14
23
21
23
16
18
17
14
10
8
12
9
18 13
25 12
16 10
16
19
25
26
16
17
14
2
4
11
Bothalia 17,2 (1987)
R estionaceae, R utaceae and Proteaceae among the
ten largest families in Fynbos only. In contrast, A s­
clepiadaceae is not im portant, and only in Fynbos is
Scrophulariaceae not one of the ten largest families.
Savanna (Table 4c) is distinguished by one im port­
ant family, V erbenaceae, one family, Rubiaceae,
that ranks am ong the ten largest in no other biome,
and one family, M esem bryanthem aceae, that does
not occur am ong the im portant families. Grassland
(Table 4d) is distinguished by the high rank of Orchidaceae and Lam iaceae, which are among the ten
largest families only in this biom e, and only here are
Sterculiaceae and Aizoaceae absent from the im­
p ortant families. N am a-Karoo (Table 4e) is the only
biome which is not distinguished from the others by
differential occurrence of families. Succulent Karoo
(Table 4f) is distinguished by the high rank of Iridaceae, which is one of the three largest families, and
Crassulaceae and G eraniaceae, which are among the
ten largest families only in this biome. Desert (Table
4g) is distinguished by the occurrence of Pedaliaceae
and B urseraceae as im portant families, by the occur­
rence of C henopodiaceae and C apparaceae among
the ten largest families, and by the absence of Iridaceae as an im portant family.
A num ber of families indicate floristic relation­
ships betw een biom es with different rainfall seasona­
lity and am ount. The four sum m er rainfall biomes
(Table 4h) are variously linked by 11 families that do
not occur as an im portant com ponent of the winter
rainfall biom es. W inter rainfall biomes (Table 4i)
are linked by the occurrence of three families, Pro­
teaceae, O xalidaceae and C am panulaceae, that are
not im portant in sum m er rainfall areas, and one
family, Poaceae, that ranks first or second in sum ­
m er rainfall biom es, but has a lower rank in the win­
ter rainfall areas.
In contrast to the above groupings based on rain­
fall seasonality, other families link biomes with simi­
lar am ounts of rainfall. The arid biomes are linked
by four families (Table 4j). C henopodiaceae and Zygophyllaceae are im portant, and Aizoaceae and M e­
sem bryanthem aceae are among the ten largest fami­
lies only in the arid biomes. Finally, a group of six
families, all with low ranking, weakly links the sum­
m er rainfall biom es G rassland and Nam a-Karoo to
the w inter rainfall biom es (Table 4k). Savanna is not
linked to the w inter rainfall biomes at family level.
C entres of diversity of large genera
The large genera (with 10 or m ore taxa) with
centres of diversity in one, two or three biomes are
listed in A ppendices 1-3. The large genera with no
apparent centre of diversity are listed in Appendix 4.
Figure 5 sum m arizes this inform ation by showing the
num bers and percentages of large genera with
centres of diversity within and shared between the
biomes.
Only in the case of Fynbos and Savanna are more
than half the large genera centred in a single biom e,
w hereas each of the other four biomes shares more
than half its large genera with another biome. The
highest num ber of large genera have their centre of
219
FIG U R E 5. — Number and percentage of large genera (10 or
more taxa) with centres of diversity in each biome and
shared between biomes. In each large circle, the upper
number is the number of large genera with a centre of
diversity only in that biome, the lower number is the total
number of large genera with a centre of diversity in that
biome, and the percentage is the percentage of large gen­
era with a centre of diversity only in that biome. The num­
ber in each small circle is the percentage of genera shared
between pairs of biomes, and the number on the line be­
tween a pair is the number of genera with shared centres of
diversity. Absence of linkage lines indicates no large gen­
era in common.
diversity in Fynbos, and 72% of these genera are
centred only in Fynbos. Fynbos is a shared centre of
diversity for similar num bers of genera with Suc­
culent K aroo and with Grassland, and for low num ­
bers with Savanna and with Nam a-Karoo. No genera
have centres of diversity in both Fynbos and D esert.
In Savanna, as in Fynbos, over half the large genera
have centres of diversity in no other biom e, and Sav­
anna also shares genera with centres of diversity in
four other biomes. No genera have centres of diver­
sity in both Savanna and Succulent Karoo. For
G rassland, over half the large genera share their
centres of diversity with Savanna, and nearly a qu ar­
ter share their centres of diversity with Fynbos.
Grassland shares large genera only with Savanna
and Fynbos, and no genera have centres of diversity
in both Grassland and Nam a-Karoo, G rassland and
Succulent Karoo or Grassland and D esert. A very
low percentage of large genera have their centre of
diversity in N am a-K aroo alone. Over two-thirds of
large genera in N am a-K aroo share their centre of
diversity with Savanna, and Nam a-K aroo shares
genera with centres of diversity in all biomes except
G rassland. In Succulent Karoo, a very high percent­
age of large genera shares a centre of diversity with
Fynbos, and a low percentage shares a centre of di­
versity with N am a-K aroo. Succulent Karoo shares
large genera only with Fynbos and N am a-K aroo,
and no genera have centres of diversity in both Suc­
culent Karoo and Savanna, Succulent K aroo and
Grassland or Succulent Karoo and D esert. Only two
genera have their diversity centred in both of the
‘karroid' biom es, and this is the lowest percentage of
shared large genera for either N am a-K aroo or Suc­
culent Karoo. Only three large genera have a centre
of diversity in D esert, and all three are shared with
220
Bothalia 17,2 (1987)
50
Savanna or with Nama-Karoo. No genera have
centres of diversity in both Desert and Grassland,
Desert and Succulent Karoo, or Desert and Fynbos.
Fynb os
25
Life forms and centres of diversity of large genera
nnr^i
s
50
S a va n n a
25
mnPiil
P
Ch
H
Cr
mnx]
T
S
50
G ra s s la n d
r e p o r te d
25
HÏÏTkn
JZ 1
forms
P
Ch
H
Cr
T
S
life
50
of
N a m a -K a ro o
25
Ch
H
Cr
50
S u c c u le n t K a r o o
25
P
Ch
H
Cr
50
D e s e rt
25
Ch
Cr
FIGURE 6. — Life form spectra of large genera (10 or more taxa)
for each biome. Life forms of genera with centres of diver­
sity only in a particular biome are shown by stripes, and life
forms in all genera with centres of diversity in a particular
as well as in other biomes are shown by stippling. Life
forms are indicated by the following symbols: P = phanerophytes; Ch = chamaephytes; H = hemicryptophytes;
Cr = cryptophytes; T = therophytes; S = succulents.
Figure 6 shows life form spectra for large genera
with centres of diversity either only in one or in more
than one biome. The basis for plant classification is
that floral characters are conservative at family and
genus level, whereas vegetative characters can be
variable between members of a higher category.
R aunkiaer’s life forms indicate broad basic differ­
ences in vegetative states, depending on the position
of the perennating bud, and indicate differences in
utilization of resources. The fact that a genus has
many species and infraspecific taxa in a certain bi­
ome suggests that the adaptations displayed by the
taxa are com patible with the environm ent of that
biome. Thus the differences in characteristics of the
genera, as illustrated by life forms, can show conver­
gent adaptations in a num ber of separate evolution­
ary lines to the conditions in the biome. However, a
centre of diversity for a genus in a particular biome
does not imply that speciation occurred either in that
biom e, or under current environm ental conditions.
The biomes are characterized by differences in the
life forms reported in the large genera. In Fynbos,
cham aephytes are the most commonly reported life
form in the large genera. In Savanna, phanerophytes
are reported more frequently than in any other bi­
ome. For Grassland, nearly half the life forms re­
ported are hemicryptophytes. Grassland differs from
Savanna by having fewer phanerophytes and cham­
aephytes (the woody com ponent), and from NamaK aroo by having fewer cryptophytes. Nama-Karoo
is similar to Grassland, but with more cryptophytes
reported among the few genera with their centre of
diversity in Nama-Karoo only. Succulent Karoo is
rem arkable because it has similar values for cham ae­
phytes, hemicryptophytes and cryptophytes. The
com parative value for cryptophytes is far higher than
for any other biom e, and phanerophytes are not re­
ported at all. The life form spectrum for Desert may
be misleading because it is based on three genera
only, and therefore it is not considered further.
The differences in occurrence of each of the life
forms in the biomes can also be examined. Phanero­
phytes appear only in genera with a centre of diver­
sity in Fynbos or Savanna. Chamaephytes and hem i­
cryptophytes show a basic difference between the
summ er and the winter rainfall biomes. C ham ae­
phytes are reported most often in winter rainfall
Fynbos and Succulent Karoo. Hemicryptophytes are
the most abundant life form in the sum m er rainfall
Savanna, Grassland, Nama-Karoo and Desert.
C ryptophytes occur in low numbers in all the bi­
om es, but are reported often only in genera with
their centre of diversity in Succulent Karoo, and to a
lesser extent, Nama-Karoo. Therophytes are re­
ported in all biomes, but are less frequently re­
ported in genera of which the centre of diversity is
confined to a single biome, and are more frequently
reported in genera with centres in more than one
221
Bothalia 17,2 (1987)
biome. Succulents are reported in all biomes, but the
mesic biom es Fynbos, Savanna and G rassland, have
succulents reported in genera with centres in each
one, while the more arid Succulent Karoo and
N am a-K aroo have succulents reported only in gen­
era with centres of diversity in more than one biome.
roo. A t family level, Grassland is linked to NamaK aroo only by families that also link it to Savanna
(Table 4h) or to Fynbos (Table 4k), while it is linked
independently to Fynbos by two families (Table 4k).
N am a-K aroo
Floristic characteristics and relationships o f the
biomes
Fynbos
Fynbos has the largest num ber of taxa, the highest
percent of unique taxa, the largest num ber of im ­
portant families that do not occur in any other bi­
om e, and the greatest num ber of centres of diversity
for large genera. A t species level, the Sorenson’s
coefficient of similarity and the percentage of shared
taxa show that Fynbos is most closely related to Suc­
culent K aroo, the other winter rainfall biome. At the
generic level, Fynbos shares m ore centres of diver­
sity for large genera with Succulent Karoo than with
any o ther biom e. At the family level, Fynbos is
linked only to Succulent Karoo by four im portant
families. The less-m arked relationship between Fyn­
bos and G rassland will be discussed under Grassland
below.
N am a-K aroo is not well defined floristically in this
study. At species level, its num ber of taxa is low,
particularly with respect to its large area, and the
percentage of unique taxa is very low, hardly higher
than that of D esert. Nam a-Karoo is the only biome
for which all Sorenson’s coefficients except one (to
Fynbos) are greater than 20. Over half of N am a-K a­
roo taxa are shared with Savanna, about a third are
shared with Grassland and another third with Fyn­
bos. A t generic level, few large genera have a centre
of diversity in N am a-K aroo, and of these, m ore have
a shared centre of diversity with Savanna, with Fyn­
bos or with Desert than are centred in N am a-K aroo
alone. At family level, Nam a-Karoo is the only bi­
om e that cannot be defined by differential occur­
rence of im portant families. It is linked to all the
other sum m er rainfall biomes, and also to the winter
rainfall Succulent Karoo through the arid biomes.
Succulent Karoo
Savanna
Savanna is second to Fynbos in num ber of taxa,
percentage of unique taxa, and in num ber of centres
of diversity for large genera. However, Savanna is
distinguished at family level by only three families,
while it is linked to the other sum m er rainfall biomes
by eight families. The closest relationship of Sav­
anna is to G rassland, as shown by the very high So­
renson’s coefficient of similarity and the percentage
of shared taxa, the num ber of large genera with
centres of diversity in both Savanna and Grassland,
and the six families that link them , three of which
are im portant only in Savanna and Grassland. A
w eaker relationship betw een Savanna and NamaKaroo is shown by a high Sorenson's coefficient and
the percentage of shared taxa, a considerable num ­
ber of large genera with centres of diversity in both
Savanna and N am a-K aroo, and by four families that
link them .
The num ber of taxa reported for Succulent Karoo
is similar to that of Nam a-Karoo, but the area cov­
ered is about a quarter as large, and Succulent Ka­
roo has m ore unique taxa. It is distinguished from
other biomes by three im portant families. Succulent
K aroo is shown by Sorenson's coefficients, by p er­
centage of shared taxa and by centres of diversity of
large genera to be related floristically both to Fynbos
and N am a-K aroo. The much higher values in every
case show that the relationship is strongest to Fynbos
(see Fynbos above). Over half the Succulent Karoo
taxa and over three quarters of the large genera are
shared with Fynbos. A t family level, the strong links
of Succulent Karoo to Fynbos are shown by four
families that are im portant only in these two biom es,
w hereas at family level Succulent Karoo is linked to
N am a-K aroo only through the group of families that
links the three arid biomes.
D esert
Grassland
A m oderately large num ber of taxa is reported for
G rassland, which is distinguished by four families.
Its relationship with Savanna is the closest dem on­
strated in this study, as discussed above. Grassland
shows similar m oderate Sorenson’s coefficients with
both N am a-K aroo and Fynbos, but other com pari­
sons show that G rassland is in fact more closely re­
lated to Fynbos than to N am a-K aroo. The percent­
age of G rassland taxa shared with Fynbos is far
higher than the percentage shared with N am a-Ka­
roo, and a num ber of large genera, nearly all hem i­
cryptophytes, have centres of diversity in both
Grassland and Fynbos, while no large genera have
centres of diversity in both Grassland and Nama-Ka-
A very small num ber of taxa are reported for D e­
sert, and the percentage of unique taxa is lower than
for any other biome. There are no large genera with
a centre of diversity in D esert alone. How ever, D e­
sert is distinguished by four im portant families. R e­
lationships of the Desert flora are shown by Soren­
son’s coefficients and by the percentage of shared
taxa, to be highest with Savanna and with Nama-Karoo, and it is only with these two biomes that Desert
shares centres of diversity for large genera. In ad­
dition, D esert is linked to Nam a-Karoo by ten fam i­
lies, two of which are im portant only in D esert and
N am a-K aroo, and it is linked to Savanna by four
families, one of which is im portant only in Desert
and Savanna. D esert is also linked to the arid but
winter rainfall Succulent Karoo by four families.
222
Bothalia 17,2 (1987)
Relationships
The distribution of species, genera and families
and the life form spectra shows that the biomes fall
floristically into two groups, which correspond to the
summer rainfall region (Savanna, Grassland, NamaKaroo, Desert) and the winter rainfall region (Fyn­
bos, Succulent K aroo). The present analysis of
14 000 taxa therefore supports and extends the ‘win­
ter rainfall biom e’ concept first put forward on the
basis of a few genera by Bayer (1984). A detailed
study of grass subfamily distributions also shows a
similar basic division, with Chloridoideae and Panicoideae most abundant in summer rainfall areas and
A rundinoideae most abundant in winter rainfall
areas (Gibbs Russell 1986).
Nam a-Karoo and Succulent Karoo, which have
previously been placed together at highest level in all
vegetation studies except that of R utherford &
Westfall (1986), are not closely related floristically.
Nam a-Karoo is more closely related to Savanna than
to Succulent K aroo, and Succulent Karoo is more
closely related to Fynbos than to Nama-Karoo.
W ithin the sum m er rainfall group, at species level,
the strongest relationship is between Savanna and
G rassland, with a w eaker relationship between Sa­
vanna and Nam a-Karoo. The same relationships are
shown at generic level, and the distinctness of NamaKaroo from Grassland and of Desert from Succulent
Karoo is emphasized. A t family level, particular fa­
milies link and dem arcate the summer rainfall bi­
omes and the winter rainfall biomes, but another
group of families complicates this simple difference
by linking the arid biomes of both summer and win­
ter rainfall regimes.
Secondary links connect the two m ajor groups
through N am a-K aroo, which lies between the other
biomes geographically. Nam a-Karoo is ill-defined as
an entity, and is strongly linked at species, genus and
family level to Savanna and D esert; it is more
weakly linked at species and family level to Succu­
lent Karoo and at genus level to Fynbos. Grassland,
which is very strongly allied to Savanna, shows a
secondary link to Fynbos, independent of Nama-Karoo, at species, genus and family level.
CONCLUSIONS
At the highest level of floristic comparison the
winter rainfall biomes and the summer rainfall bi­
omes form two separate groups. Within these
groups, each biome is floristically distinct at the level
of species and infraspecific taxa, whether m easured
by Sorenson's coefficient of similarity or by percent­
age of shared taxa, and each biome (except Desert)
is rich in taxa. Each is a centre of diversity for certain
large genera, and the life form spectrum for these
genera is different for each biome. Each (except
Nam a-K aroo) is distinguished by differences in the
occurrence of im portant plant families.
The floristic distinctness of the biomes, coupled
with high taxon num bers, implies that each should
be studied and m anaged as a separate entity. Be­
cause of the high num bers of species and infraspe­
cific taxa, it is unlikely that conservation of limited
areas in nature reserves will protect a large propor­
tion of the taxa in any one biome.
This study is ham pered by the dearth of specimen
records from arid areas, and for this reason it may be
criticized for being too preliminary. However, the
trends indicated should serve as stimulus to more
precise analyses. Unfortunately precision can only
be achieved when primary data are available to com ­
pile more complete and accurate checklists. This
should be done through bringing together records
from many herbaria and from literature, and most
im portant, through rationally planned specimen col­
lecting designed to cover all biomes adequately.
The conclusions are based on plant distributions
as they are now known, that result from interactions
over a long geological, climatological and evolution­
ary history. It is not apparent to what extent these
distributions have been influenced by present or past
environm ents. However, listing and comparing the
taxa in each biome is the first step in unravelling the
events that have led to the formation of its character­
istic flora. PRECIS has given us a preliminary look
that will allow the generation of hypotheses for more
rigorous testing using stronger data sets and more
refined techniques.
ACKNOWLEDGEMENTS
The existence of PRECIS is due to the fore­
sightedness and tenacity of D r B. de W inter, who
stood by the system from its beginning. J. C. Mogford searched PRECIS for the basic species lists, and
B. C. de W et wrote com puter programs to generate
subsidiary lists. R. H. Westfall, C. Hilton-Taylor,
E. J. Moll and R. M. Cowling discussed particular
points. W. Roux provided technical assistance and
B. B. Gibbs assisted with mapping.
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BAY ER . M. B. The Cape Flora and the Karoo. Veld and Flora
70: 17-19.
BO N D , P. & GOLDBLATT. P. 1984. Plants of the Cape Flora
— a descriptive catalogue. Journal o f South African Bot­
any Supplement 13.
BR EN A N , J. P. M. 1978. Some aspects of the phytogeography of
tropical Africa. Annals o f the Missouri Botanical Garden
65: 437-478.
D Y ER , R. A. 1975. The genera o f southern African flowering
plants, Vol. 1. Dicotyledons. Department of Agricultural
Technical Services, Pretoria.
D Y E R , R. A . 1976. The genera o f southern African flowering
plants, Vol. 2. Monocotyledons. Department of Agricul­
tural Technical Services, Pretoria.
GIBBS RUSSELL, G. E. 1975. Comparison of the size of various
African floras. Kirkia 10: 123-140.
GIBBS RUSSELL, G. E. 1985a. PRECIS, the National Her­
barium’s computerized information system. South African
Journal o f Science 81: 62-65.
GIBBS RUSSELL, G. E. 1985b. Analysis of the size and compo­
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GIBBS RUSSELL, G. E. 1986. Significance of different centres
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GIBBS RUSSELL, G. E. & GONSALVES, P. 1984. PRECIS —
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GIBBS RUSSELL, G. E ., RETIEF, E. & SMOOK, L. 1984.
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G OLD BLATT, P. 1978. Analysis of the flora of southern Africa:
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SCHEEPERS, J. C. 1982. The status of conservation in South
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SO RENSO N, T. 1948. A method for establishing groups of equal
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APPENDIX 1.— Large genera (10 taxa or more) with centre o f
diversity in one biome. * = genera reported only from a
single biome. Life forms are abbreviated: P, phanerophyte;
Ch, chamaephyte; H, hemicryptophyte; Cr, cryptophyte;
T, therophyte; S, succulent
a. Large genera with centre o f diversity reported for Fynbos only
Family and genus
Pottiaceae
Tortula
Poaceae
Merxmuellera
Pentaschistis
Cyperaceae
Ficinia
Isolepis
Tetraria
Restionaceae
Restio
Chondropetalum*
Elegia*
Leptocarpus
Thamnochortus
Hypodiscus*
Juncaceae
Juncus
Liliaceae s. 1.
Wurmbea
Trachyandra
Haworthia
Omithogalum
Lachenalia
Hypoxidaceae
Spiloxene
Iridaceae
Romulea
Galaxia
Moraea
Homeria
Bobartia*
Aristea
Geissorhiza
Ixia
Tritonia
Gladiolus
Tritoniopsis*
Watsonia
% o f the
Total no.
o f taxa reported taxa
reported in Fynbos
Life
12
83
H
12
47
66
82
H
H
54
19
35
98
78
97
H
H
H
109
19
36
22
29
12
94
100
100
100
100
100
H
H
H
H
H
H
19
89
H
12
44
22
44
46
91
54
63
59
82
Cr
Cr
H, S
Cr
Cr
15
86
Cr
51
11
62
22
12
29
58
41
17
103
13
16
62
81
64
63
100
82
98
97
58
72
100
81
Cr
Cr
Cr
Cr
H
H
Cr
Cr
Cr
Cr
Cr
Cr
Orchidaceae
Holothrix
Satyrium
Disa
Monadenia
Corycium
Proteaceae
Paranomus
Serruria
Spatalla
Protea
Leucospermum
Leucadendxon
Santalaceae
Thesium
Mesembryanthemaceae
Drosanthemum
Erepsia*
Lampranthus
Caryophyllaceae
Silene
Droseraceae
Drosera
Crassulaceae
Crassula
Adromischus
Bruniaceae
Rasp alia
Berzelia
Rosaceae
Cliffortia
Fabaceae
Cyclopia*
Podalyria
Priestleya
Rafnia
Lebeckia
Aspalathus
Geraniaceae
Pelargonium
Oxalidaceae
Oxalis
Rutaceae
Agathosma
Adenandra*
Acmadenia*
Diosma
Euchaetis
Polygalaceae
Polygala
Mural tia
Euphorbiaceae
Clutia
Rhamnaceae
Phylica
Malvaceae
Anisodontea
Sterculiaceae
Hermannia
Thymelaeaceae
Gnidia
Struthiola
Lachnaea
Passe rina
Apiaceae
Centella
Peucedanum
Ericaceae
Erica
Blaeria*
Grisebachia
Simocheilus*
Syndesmanthus*
Schyphogyne*
Plumbaginaceae
Limonium
Gentianaceae
Chiionia
Boraginaceae
Lobostemon
H
H
H
H
H
13
32
59
12
13
69
75
79
91
69
13
57
15
62
39
64
100
100
100
87
97
93
P, Ch
Ch
Ch
P, Ch
P, Ch
P, Ch
95
54
Ch, H
17
12
43
64
100
86
Ch, S
Ch, S
Ch, S
12
91
H
16
75
H
137
15
54
53
Ch, H, S
Ch, S
10
10
100
100
77
96
P, Ch
17
12
16
18
24
220
100
100
100
100
70
97
Ch
Ch
Ch
Ch, H
Ch, H
P, Ch
121
89
Ch, H, Cr, T
135
68
Ch, H, Cr, T
68
23
11
20
20
100
100
100
100
100
50
91
58
95
Ch, H
Ch
24
75
Ch
93
97
P, Ch
12
83
Ch, H
145
46
Ch, H
64
25
20
14
71
100
100
92
Ch
Ch
Ch
Ch
34
15
100
53
H
Ch, H
460
12
10
17
11
12
96
100
70
100
100
100
P, Ch
Ch
Ch
Ch
Ch
Ch
16
87
Ch, H
15
66
Ch, H
21
100
Ch
Ch
Ch
Ch
Ch
Ch
Ch
Ch
Bothalia 17,2 (1987)
Scrophulariaceae
Polycarena
Harveya
Selaginaceae
Selago
Rubiaceae
Anthospermum
Campanulaceae
Roella*
Prismatocarpus
Lightfootia
Lobeliaceae
Cyphia
Lobelia
Monopsis
Asteraceae
Mairea
Felicia
Helipterum
Stoebe
Metalasia
Relhania
Athanasia
Cotula
Senecio
Euryops
Osteospermum
Ursinia
Cullumia
23
15
60
73
H, T
H
61
63
Ch
17
70
Ch
23
21
35
100
90
77
27
51
13
55
70
92
H, Cr
Ch, H, T
H, T
12
62
11
21
23
18
25
22
182
46
56
37
13
100
66
100
100
91
77
88
59
48
54
66
78
92
Ch, H
Ch, H
H, T
Ch
Ch
Ch, T
Ch
H, T
Ch, H, S
Ch, H, T
Ch, H
Ch, H, T
Ch
Ch, H
Ch, H
Ch, H
b. Large genera with centre o f diversity reported for Savanna only
Total no.
% o f the
Family and genus
of taxa reported taxa
Life form
reported in Savanna
Ricciaceae
Riccia
Marsileaceae
Marsilea
Adiantaceae
Cheilanthes
Zamiaceae
Encephalartos
Poaceae
Brachiaria
Panicum
Pennisetum
Sporobolus
Eragrostis
Cyperaceae
Mariscus
Fuirena
Eleocharis
Liliaceae s. 1.
Chlorophytum
Urginea
Dipcadi
Protasparagus
Amaryllidaceae
Crinum
Moraceae
Ficus
Loranthaceae
Tapinanthus
Viscaceae
Viscum
Amaranthaceae
Am aran thus
Capparaceae
Maerua
Fabaceae
Albizia
Acacia
Cassia
Crotalaria
Indigofera
Psoralea
Tephrosia
Sesbania
20
55
H
11
90
H
26
57
H
10
70
P, Ch
19
35
14
38
81
100
97
64
89
88
H
H
H
H
H
32
13
10
90
76
90
H
H
H
11
17
14
41
54
47
92
63
Cr
Cr
Cr
Ch
18
94
Cr
18
100
P
16
100
Ch
13
61
Ch
12
83
T
12
83
P, Ch
10
63
22
50
170
38
49
17
90
79
90
90
52
97
88
82
P, Ch
P, Ch
P, Ch, H
Ch, H
Ch, H
Ch, H
Ch, H
P, Ch, H
Aeschynomene
Rhynchosia
Vigna
Euphorbiaceae
Phyllanthus
Croton
Jatropha
Euphorbia
Anacardiaceae
Ozoroa
Vitaceae
Cyphostemma
Tiliaceae
Corchorus
Grewia
Triumfetta
Malvaceae
Abutilon
Pavonia
Hibiscus
Sterculiaceae
Melhania
Ochnaceae
Ochna
Elatinaceae
Bergia
Lythraceae
Nesaea
Combretaceae
Combretum
Ebenaceae
Diospyros
Asclepiadaceae
Ceropegia
Huemia
Convolvulaceae
Ipomoea
Verbenaceae
Clerodendrum
Lamiaceae
Leonotis
Lentibulariaceae
Utricularia
Acanthaceae
Barleria
Blepharis
Justicia
Rubiaceae
Kohautia
Oldenlandia
Canthium
Asteraceae
Geigeria
Dicoma
10
44
14
80
73
100
Ch, H, T
Ch, H
H
14
10
15
123
78
100
86
46
P, Ch, H
P, Ch, H
Ch, H
P, Ch, H, S
13
84
P, Ch
23
78
Ch, H
12
24
11
100
91
91
Ch, H
P, Ch
Ch, H
16
11
45
93
72
93
10
100
10
90
P, Ch
10
90
Ch, H
16
87
Ch, H, T
32
96
P, Ch
19
73
P, Ch
21
17
95
82
H, S
H, S
43
90
Ch, H, T
10
100
P, Ch, H
11
91
Ch, H
14
92
H
47
35
24
85
65
87
Ch
Ch, H, T
Ch, H
14
13
14
85
100
92
Ch, H, T
Ch, H
P, Ch
14
14
92
78
P, Ch, H
Ch, H
P, Ch, H, T
Ch, H
Ch, H
Ch, H
c. Large genera with centre o f diversity reported for Grassland
only
Total no.
% o f the
Family and genus
o f taxa reported taxa
Life form
reported in Grassland
Cyperaceae
Carex
Liliaceae s.1.
Kniphofia
Agapanthus
Tulbaghia
Amaryllidaceae
Nerine
Cyrtanthus
Iridaceae
Dierama
Mesem bry an them aceae
Delosperma
Portulacaceae
Anacampseros
Brassicaceae
Lepidium
13
69
H
23
11
12
73
63
75
H
H
H
14
20
57
55
Cr
Cr
10
100
Cr
24
79
Ch, H, S
11
45
Ch, H, S
13
53
Ch, H, T
Bothalia 17,2 (1987)
225
Fabaceae
Lotononis
Pearsonia
Onagraceae
Oenothera
Apiaceae
Alepidea
Asclepiadaceae
Aspidoglossum
Pachycarpus
Lamiaceae
Stachys
Salvia
Scrophulariaceae
Zaluzianskya
Gesneriaceae
Streptocarpus
Asteraceae
Helichrysum
Gerbera
33
10
45
90
Ch, H
Ch, H
12
91
Ch, H, T
13
92
H
12
13
83
84
H
H
29
25
51
60
Ch, H, T
Ch, H
10
45
H, T
10
50
H
147
12
55
50
Ch, H
H
d. Large genera with centre o f diversity reported for Succulent
Karoo only
Total no.
% o f the
Family and genus
Life form
o f taxa reported taxa
reported in Succulent
Karoo
Liliaceae s. 1.
Androcymbium
Iridaceae
Lapeirousia
Aizoaceae
Galenia
Crassulaceae
Tylecodon
21
57
Cr
13
48
Cr
26
61
Ch, H
13
76
Ch, H, S
e. Large genera with centre o f diversity reported for NamaKaroo only
Total no.
% o f the
Family and genus
o f taxa reported taxa
Life form
reported in NamaKaroo
Mesembryanthemaceae
Lithops
Asteraceae
Pentzia
12
83
H, S
25
60
Ch, H
APPENDIX 2 .— Large genera (10 taxa or more) with centres o f
diversity in tw o biomes. Life forms are abbreviated: P, phanerophyte; Ch, chamaephyte; H, hem icryptophyte; Cr,
cryptophyte; T, therophyte; S, succulent
a. Large genera with centre o f diversity reported for Savanna and
Grassland
Family and genus
Aspleniaceae
Asplenium
Poaceae
Andropogon
Hyparrhenia
Digitaria
Setaria
Aristida
Cyperaceae
Cyperus
Pycreus
Kyllinga
Total no.
o f taxa
reported
% o f reported
taxa in:
Savanna Grassland
Life 1
13
62
62
H
12
17
29
17
38
67
100
93
88
92
83
65
62
59
55
H
H
H
H
H, T
63
18
10
84
89
70
54
56
80
H, T
H, T
H, T
Schoenoplectus
Bulbostylis
Scleria*
Commelinaceae
Commelina
Liliaceae s. 1.
Anthericum
Ledebouria
Hypoxidaceae
Hypoxis
Dioscoreaceae
Dioscorea
Orchidaceae
Habenaria
Eulophia
Polygonaceae
Polygonum
Chenopodiaceae
Chenopodium
Fabaceae
Eriosema
Euphorbiaceae
Acalypha
Chamaesyce
Anacardiaceae
Rhus
Malvaceae
Sida
Oleaceae
Jasminum
Asclepiadaceae
Asclepias
Brachystelma
Convolvulaceae
Convolvulus
Verbenaceae
Chase anum
Lamiaceae
Plectranthus
Hemizygia
Solanaceae
Solanum
Scrophulariaceae
Alectra
Rubiaceae
Pavetta
17
10
13
76
90
85
71
90
46
H, T
H, T
H
19
95
53
H, T
17
12
88
92
53
83
Cr
Cr
20
50
80
Cr
16
88
50
Ch, H, Cr
18
35
50
66
61
51
H, Cr
H
15
66
60
Ch, H
21
76
52
H, T
22
68
64
Ch, H
16
10
94
90
62
50
P, Ch, H
H
61
52
48
P, Ch
13
92
54
Ch, H
10
70
50
Ch
37
20
57
70
81
45
Ch, H
H
20
60
70
H
13
69
62
Ch, H
29
15
76
67
48
47
Ch, H, T
Ch, H
38
68
53
P, Ch, H
11
73
55
H, T
14
93
50
P, Ch
b. Large genera with centres o f diversity reported for Savanna
and Nama-Karoo
% o f reported
Total no.
Life form
Family and genus
o f taxa
taxa in:
reported
Savanna NamaKaroo
Aizoaceae
Limeum
Capparaceae
Cleome
Boscia
Fabaceae
Melolobium
Burseraceae
Commiphora
Boraginaceae
Heliotropium
Solanaceae
Lycium
Scrophulariaceae
Aptosimum
Selaginaceae
Walafrida
Acanthaceae
Petalidium
Monechma
Cucurbitaceae
Cucumis
28
75
50
Ch, H, T
19
10
89
70
50
50
H, T
P, Ch
15
53
53
Ch
27
67
55
P, Ch
15
80
73
Ch, H
14
64
57
P, Ch
15
93
67
Ch, H
14
50
57
Ch, H, T
25
22
52
59
72
68
Ch, H
Ch
15
87
47
H, T
226
Bothalia 17,2 (1987)
c. Large genera with centres o f diversity reported for Savanna
and Fynbos
Total no.
% o f reported
Family and genus o f taxa
taxa in:
Life form
reported
Savanna Fynbos
Dicranaceae
Campylopus
Crassulaceae
Cotyledon
Celastraceae
Cassine
Ebenaceae
Euclea
Asclepiadaceae
Cynanchum
13
62
77
H
11
45
55
Ch, H, S
12
50
75
P, Ch
18
67
61
P, Ch
10
50
50
Ch, H
d. Large genera with centres o f diversity reported for Fynbos
and Grassland
Total no.
% o f reported
Family and genus
o f taxa
taxa in:
Life form
reported
Fynbos Grassland
Bryaceae
Bryum
Poaceae
Agrostis
Orchidaceae
Disperis
Polygonaceae
Rumex
Chenopodiaceae
Atriplex
Caryophyllaceae
Dianthus
Fabaceae
Argyrolobium
Trifolium
Geraniaceae
Geranium
Gentianaceae
Sebaea
Asclepiadaceae
Schizoglossum
Rubiaceae
Galium
Asteraceae
Cineraria
15
60
73
H
13
54
54
H
17
47
47
H
13
77
77
Ch, H
10
50
70
Ch, H
18
44
50
H, T
22
18
50
61
59
55
Ch, H
H
12
50
50
H, T
35
54
46
H, T
13
46
62
H
13
77
54
Ch, H
20
50
60
Ch, H
29
90
45
H
23
22
65
55
48
55
Cr
Cr
16
11
56
82
56
45
Cr
Cr
25
51
48
57
60
49
Cr
Cr
22
27
77
56
55
67
Ch, H, T
Ch, H, T
60
72
47
Ch, H, T
10
70
80
Ch
11
39
32
45
62
50
50
46
50
H, T
Ch, H, T
Ch, H, T
23
57
48
Ch, H, T
55
34
18
55
68
61
58
53
61
Ch, H, S
H
H, T
f. Large genera with centres o f diversity reported for Fynbos
and Nama-Karoo
Total no.
% o f reported
Life form
o f taxa
taxa in:
Family and genus
reported
Fynbos NamaKaroo
Chenopodiaceae
Salsola
Asteraceae
Pteronia
24
58
63
Ch, H
52
46
42
Ch
g. Large genus with centres o f diversity reported for NamaKaroo and Succulent Karoo
Family and genus
e. Large genera with centres o f diversity reported for Fynbos
and Succulent Karoo
Total no.
% o f reported
Family and genus o f taxa
taxa in:
Life form
reported
Fynbos Succulent
Karoo
Poaceae
Ehrharta
Liliaceae
Bulbine
Albuca
Amaryllidaceae
Haemanthus
Gethyllis
Iridaceae
Hesperantha
Babiana
Aizoaceae
Phamaceum
Tetragonia
Brassicaceae
Heliophila
Fabaceae
Wiborgia
Scrophulariaceae
Diascia
Nemesia
Manulea
Selaginaceae
Hebenstretia
Asteraceae
Othonna
Arctotis
Gazania
Asteraceae
Eriocephalus
Total no.
of taxa
reported
% o f reported
taxa in:
Nama- Succulent
Karoo
Karoo
19
63
Life form
Ch
58
h. Large genus with centres o f diversity reported for NamaKaroo and Desert
Total no.
% o f reported
Family and genus o f taxa
taxa in:
Life form
reported
NamaDesert
Karoo
Mesem bry an them ace ae
Psilocaulon
19
47
32
H, T
APPENDIX 3.— Large genera (10 taxa or more) with centres o f
diversity in three biomes. Life forms are abbreviated: P,
phanerophyte; Ch, chamaephyte; H, hemicryptophyte;
Cr, cryptophyte; T, therophyte; S, succulent
a. Large genera with centres o f diversity reported for Savanna,
Grassland and Fynbos
Total no.
% o f reported
Family and
o f taxa
taxa in:
Life form
genus
reported Savan- Grassrynna
land
bos;
Fissidentaceae
Fissidens
Celastraceae
Maytenus
Asteraceae
Conyza
23
52
52
70
H
17
71
47
59
P, Ch
13
62
54
92
Ch, H, T
227
Bothalia 17,2 (1987)
b. Large genera with centres o f diversity reported for Savanna,
Nama-Karoo and Desert
Total no.
% o f reported
o f taxa
taxa in:
Family and
Life form
reported Savan- Nama- Desert
genus
na
Karoo
APPENDIX 4 .— Large genera (10 taxa or more) with no apparent
centre o f diversity. Life forms are abbreviated: P,phanerophyte; Ch, chamaephyte; H,hemicryptophyte; Cr,cryptophyte; T, therophyte; S, succulent
Family and genus
Poaceae
Stipagrostis
Pedaliaceae
Sesamum
34
50
65
68
H
14
71
50
50
H, T
c. Large genus with centres o f diversity reported for Fynbos,
Succulent Karoo and Nama-Karoo
% o f reported
Total no.
taxa in:
.I .iTP
. form
r
o f taxa
Family and
reported Fyn­ Succu- Nama- L1Ie Iorm
genus
lent
Karoo
bos
Karoo
Zygophyllaceae
Zygophyllum
30
50
53
57
Ch
d. Large genus with centres o f diversity reported for Fynbos,
Savanna and Nama-Karoo
Total no.
%o f reported
Family and
o f taxa
taxa in:
^ife fQn
genus
reported Fyn- Savan- Namabos
na
Karoo
Geraniaceae
Monsonia
10
50
50
50
Ch,H ,T,S
Liliaceae s. 1.
Eriospermum
Aloe
Iridaceae
Brunsvigia
Mesembryanthemaceae
Ruschia
Fabaceae
Lessertia
Asclepiadaceae
Stapelia
Scrophulariaceae
Sutera
Campanulaceae
Wahlenbergia
Asteraceae
Berkheya
Total no.
Vegetation type
with largest %
o f taxa
Life form
39
98
Savanna
Savanna
41
44
Cr
Ch, S
11
Fynbos
36
Cr
55
Fynbos
40
Ch, S
33
Fynbos
42
Ch, H
27
Fynbos
44
H, S
72
Savanna
42
Ch, H, T
46
Grassland
35
H, T
43
Grassland
47
Ch, H