B othalia 15. 3 & 4: 613-629 (1985)
Analysis of the size and com position o f the southern African flora
G. E . G IB B S RUSSELL*
keywords; endemic spccies. flora, phy(oleography, plant families, species diversity
ABSTRACT
The southern African flora has been surveyed for the first time at spccies level in the List o f Species o f Southern
A frican Plants (Gibbs Russell e ta l., 1984). The numbers o f taxa recorded for southern Africa are compared to the
numbers reported from other parts o f Africa, and the largest families in each area are listed and compared The
species richness o f southern Africa is compared to that o f o th er parts o f the world. The numbers of genera, species
and infraspecific taxa are given for each familv in the souihern African flora, and compared to previous counts bv
D ver (1975. 1976) and G oldblatt (I97H).
INTRODUCTION
T he rem arkable diversity and high level o f e n d e ­
mism in the southern African flora has been re ­
ported by a n um ber o f authors, notably A dam son
(1938). W eim arck (1941), Levyns (1964) and G ood
(1974). and has been discussed in great detail by
G oldblatt (1978). U ntil recently there was no m od­
ern inventory o f the taxa on the subcontinent, but
the publication o f the List o f Species o f Southern
African Plants (G ibbs Russell et al.. 1984) now p ro ­
vides for th e first time a com plete coverage o f the
en tire flora. T he com ponents of the southern Afri­
can flora can now be precisely analysed and com ­
parisons can be m ade with floras o f o th er parts o f
A frica and with previous estim ates o f the southern
A frican flora. T he relative im portance o f present
studies can be assessed, and future w ork o n the
Flora o f Southern Africa can be planned w ith a m ore
accurate idea o f the m agnitude o f the task,
M ETHODS
T h e num bers o f taxa reported here for southern
A frica are taken from the P R E C IS list o f 30 June
1984. and som e m odifications have been m ade since
the first edition o f the List o f Species went to press in
O c to h c r 1983. T he taxa in the southern A frican flora
w ere co u n ted by com puter, and have been verified
by a m anual count o f the List o f Species. C ounts for
o th er Floras in Africa were m ade by hand, as d e ­
scribed in G ibbs Russel! (1974),
Because the Floras considered for this study differ
in th e delim itation o f families and in the level o f re­
cognition o f species and infraspecific tax a. it was
necessary to adopt a uniform treatm ent in o rd e r to
com pare them . Families are treated sensu lato , and
th e genus and species counts for the segregate fami­
lies are added to give a single count in these cases.
N otable exam ples o f families treated in this way arc
A izoaceae (includes M esem bryanthem aceae). Asclepiadaceae (includes Periplocaceae), C am panulaceae (includes Lobeliaceae), Fabaceae (includes
C aesalpinioideae. M im osoideae and Papilionoid e a e ), Liliaceac (includes A lliaceae, A sparagaceae,
* Botanical Research Institute, Department of Agriculture &
W ater Supply. Private Bag X101. Pretoria 00(11.
A sp h o d e la c e a e , C o lc h ie a c e a e . D ra c a e n a c e a e ,
Eriosperm aceae and H yacinthaceae) and Scrophulariaceae (includes Selaginaceae). T he alternative to a
broad acceptance o f these families w ould have been
to split them apart in Floras which treat them as
units. This was not done because an object o f the
study is to convey an overall picture o f the southern
African flora in relation to the floras of o th er parts
o f A frica, and it was therefore m ore consistent to
accept these families in the broadest sense.
It was also necessary to adopt as far as possible a
uniform treatm ent o f the low er tax a, especially those
o f infraspecific rank. Because one author's species
may be another author’s subspecies o r variety, the
total species num ber for different accounts o f the
sam e group can differ considerably, and are not
readily com parable. For this reason, com bined totals
o f species plus infraspecific taxa w ere used o n the
tables below' for purposes o f com parison, For ex­
am ple, Crassula was revised for southern Africa by
T olken (1977). and this revision is followed in the
List o f Species. There are now 237 taxa, including
142 species with 47 subspecies, 39 varieties and 9 re­
cognized hybrids. Exam ination o f his treatm ent
shows that the great m ajority o f taxa now accepted
by him at the infraspecific level w ere originally re ­
cognized as species. O f the 29 species given for the
C ape Peninsula by A dam son & S alter (1950). 9 are
accepted at the infraspecific level by T olken (1977).
If these treatm ents were com pared a t the level o f
species, 30% o f the Crassula species in A dam son &
Salter (1950) would not be counted in the List o f
Species that follows T olken, thus giving the A dam ­
son & Salter (1950) count a falsely high com parative
value.
Just as the different Floras considered here cannot
be directly com pared because o f differences in tre a t­
m ent, so the different parts o f the List o f Species it­
self vary widely in their ranking o f taxa because the
list is the result o f taxonom ic judgem ent by n u m er­
ous individuals m ade over at least 80 years. A re ­
cently revised group such as Crassula may contain
fewer species and m ore infraspecific taxa. while a
group greatly in need of revision, such as the entire
family M esem bryanthem aceae, presently has a great
m any species that will probably be reduced when
they are critically studied. T he num bers o f species
614
B othalia 15, 3 & 4 (1985)
and infraspecific taxa is therefore used as a conserva­
tive ‘low est com m on denom inator' m aking it pos­
sible to trea t at m ore o r less the sam e level Che floras
o f different areas studied at different tim es by differ­
en t individuals.
taxa once a basic list is p rep ared , the total num bers
can in fact be calculated in a num ber o f ways d e ­
pending o n the em phasis th at is required. Infraspe­
cific, naturalized and well-known but as yet unpub­
lished taxa may be included o r excluded. T he two
m ost extrem e o f these different totals are used below
to m ake com parisons with the floras o f o th er areas.
T he to tal num ber o f species and infraspecific taxa
(including naturalized tax a, unpublished taxa, sub­
species, varieties and recognized hybrids) is a ‘high’
total (Table 1), and the num ber o f indigenous
species is a ‘low ’ total (T able 2).
T he problem o f outright synonym y has been im ­
possible to solve w hen w orking a t a continental scale
o v er a tim e span o f several decades. T he ideal would
be to work through each o f the Floras considered
w ith th e aid o f th e most recent taxonom ic revisions
and thus ensure that each taxon is recognized in the
sam e way. H ow ever, this would be equivalent to re­
vising the entire A frican flora before m aking the
com parisons presented here. Because this is totally
im practicable a t p resen t, each o f the Floras covered
is taken as it stands and the taxa accepted by the
au th o r o f each treatm ent are accepted in this study,
even though som e o f the taxa counted have been, or
should have b een , placed in synonym y. T he use of
species and infraspecific taxa w hen m aking the com ­
parisons eases som e o f the discrepancies introduced
by different levels o f treatm ent a t different times,
but cannot elim inate them,
T h e total num ber o f species and infraspecific taxa
is used to com pare the Floras o f different areas, and
different parts o f the List o f Species, fo r the reasons
o f inconsistencies in level o f taxonom ic treatm ent
given above. T he ‘high’ total is also used to m ake
estim ates o f the outstanding w ork for the Flora o f
Southern Africa because all infraspecific and natura­
lized taxa must b e dealt with. In practical term s both
o f these can be tim e-consum ing to cover for the
Flora.
T he total num ber o f indigenous species m ust be
used for biogeographical studies because the natura­
lized aliens, which have only recently becom e part of
the African vegetation, are elim inated. This 'low '
count is used to calculate species/area ratios to com ­
pare the diversity o f the southern A frican flora to
that o f o th er parts o f the world. It is also used to
RESULTS AND DISCUSSION
Total numbers o f taxa in the southern African flora
T he num bers o f taxa present in southern Africa
are shown in T ables ! & 2, A lthough it may appear
to be a sim ple m atter to determ ine total num bers o f
TABLE 1, — Numbers o f taxa present in southern Africa
No.
families
No.
genera
No.
species
Bryophyta
Pteridophyta
Gymnospermae
Monocotyledonae
Dicotyledonae
Total
88
28
6
37
163
322
291
74
6
502
Í 794
2 667
821
251
43
4 491
15 881
21 487
Non-seed plants
Vascular plants
Seed plants
Flowering plants
116
234
206
2<K)
365
2 376
2 302
2 2%
1 072
20 666
20 415
20 372
+
No. infrasp,
taxa
_
Species &
infrasp. taxa
Unpubl.
taxa
_
Total species
& infrasp.
taxa
0
17
0
429
1 803
2 249
821
268
43
4 920
17 684
23 736
5
5
0
209
t21
340
826
273
43
5 129
17 805
24 076
17
2 249
2 232
2 232
1 089
22 915
22 647
22 604
10
335
330
330
1 099
23 2S0
22 977
22 934
TABLE 2. — Numbers of naturalized and indigenous families, genera and species in southern Africa
No.
No.
No.
families ■
- naturaliz. = indigcn.
families
families
No.
genera
No.
No.
- naturaliz. = indigen.
genera
genera
No.
species
No,
Total
No.
- naturaliz. + unpubl. = indigenous
species
species
species
Bryophyta
Pteridophyta
Gymnospermae
Monocotyledonae
Dicotyledonac
Total
88
28
6
37
163
322
0
1
1
1
8
11
88
27
5
36
155
311
291
74
6
502
1 794
2 667
0
4
1
36
189
230
291
70
5
466
1 605
2 437
821
25!
43
4 491
15 881
2! 487
0
9
6
119
514
648
5
5
0
183
21
214
826
247
37
4 555
15 388
21 053
Non-seedplants
Vascular plants
Seedplants
Flowering plants
116
234
206
200
!
11
10
9
115
223
196
191
365
2 376
2 302
2 296
4
230
226
225
361
2 146
2 076
2 071
1 072
20 666
20 415
20 372
9
648
639
633
10
209
204
204
I 073
20 227
19 980
19 943
B othalia 15, 3 & 4 (1985)
615
com pare th e cu rrent List o f Species to th e earlier es­
tim ates of Oyer (1975, 1976) and G oldblatt (1978),
w ho published only species counts.
Previous estim ates and counts for the num ber o f
indigenous species in Africa have been considerably
sm aller than the totals presented in the List o f
Species. F o r seed plants, Killick (1971) estim ated
17 500 species, D yer (1975, 1976) estim ated about
18 400 species, and G oldblatt (1978) reported 18 532
species, w hereas the count obtained from the List o f
Species (1984) is 19 980. A hand count o f the in­
digenous species o f vascular plants m ade by W ells et
al. (1983) yielded 20 044 species, which is w ithin 100
species o f th e count o f 20 139 determ ined from the
List o f Species. This is independent confirm ation o f
th e accuracy o f the com puterization process, The
count was o b tained by different individuals using a
different m ethod for a different purpose, but w ork­
ing on th e sam e herbarium collection at the sam e
tim e.
flora a re shown in Table 3. All these families are
flowering plants, and account for over 82% o f the
entire flora, and 87% o f th e flowering plants.
Tw elve families have around 500 o r m ore species
and infraspecific taxa, with a break o f nearly 100
taxa betw een the rest, which have few er than 400
taxa. T he 12 largest families account fo r over 58% of
the total flora and over 60% o f the flowering plants.
A s currently treated, the largest family is M esembryanthem aceae, but it is believed th at critical re ­
vision will bring the num ber o f accepted taxa down
to ab o u t 1 200 (G ibbs Russell & G len , 1984). T h e
family would then rank third, below A steraceae and
Fabaceae.
The largest families in the southern African flora
T hese 38 families are only 12% o f th e to tal num ­
b er o f fam ilies, and the 8 families that contain about
half the total flora are less than 3% o f the total num ­
b er o f families. W hen the families are arranged
according to the num ber o f species they contain, it is
found th at o ver half of all families have few er than 8
species and infraspecific taxa.
T h e 38 families th at com prise m ore than 100
species a n d constitute 0,5% o r m ore o f the total
G ood (1974) lists the 30 largest families in th e
w orld. T en o f the 12 largest families in southern
TA B LE 3, — The 38 families o f flowering plants with m ore than 100 species ranked by numbers o f species and subspecific taxa
Rank
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
Family
No. spp. &
infrasp. taxa
No.
spp.
No,
genera
Spp/,
gen.
% of
total
flora
Running
total
of spp. &
infrasp. taxa
Running
% of
flora
2 684
2 417
1 802
1 142
1 024
984
955
892
568
526
487
480
392
362
346
306
301
279
273
257
243
236
233
22!
218
210
205
203
199
186
181
180
178
171
161
150
130
120
2 408
2 116
I 540
1 066
858
804
783
769
543
461
464
439
366
351
215
291
282
267
256
225
195
207
184
176
214
205
198
159
189
175
141
150
176
113
139
129
104
106
123
180+50*
122+13*
57+2*
46+1*
24
171 + 28*
58+1*
53+5*
43+5*
36
54
13+1*
41
5
20+1*
12
5
12
32+5*
2
59+1*
21
35+7*
10
4
17
8
9
7
6
13+4*
6
15 + 19*
15+6*
13+2*
14+1*
10+4*
19,5
11,7
12,6
18,7
18,6
33,5
4,6
13,3
10,2
10,7
12,9
8,2
28,2
8,6
43,0
14,6
23,5
53,4
21.3
7,0
97,5
3,5
8,8
5,0
21,4
51.3
11,6
19.9
21.1
25,0
23.5
11.5
29,3
7,5
9,3
9,9
7.4
10,6
11.2
10,1
7,5
4,8
4.3
4,1
4,0
3.7
2,3
2,2
2,0
2,0
1,6
1,5
1,0
1,3
1,3
1,2
1.1
1,1
1,0
1,0
1,0
0,9
0,9
0,9
0,9
0,9
0.8
0,7
0.7
0.7
0.7
0,7
0,7
0.6
0,5
0,5
2 684
5 101
6 903
8 045
9 069
10 053
11 008
11900
12 468
12 994
13 481
13 961
14 353
14 715
15 061
15 367
15 668
15 947
16 220
16 447
16 720
16 956
17 189
!7 410
17 628
17 838
18 043
18 246
18 445
18 631
18 812
18 992
19 170
19 341
19 502
19 652
19 782
19 902
11,2
21,3
28,8
33,5
37,8
41,9
45,9
49,6
52,6
54,1
56,2
58,2
59,8
61,3
62,8
64,0
65,3
66,5
67,7
68,6
69,6
70,6
71,6
72,5
73,4
74,3
75,2
76,1
76,9
77,6
78,4
79,1
79,9
80,6
81,3
81,9
82,4
82,9
Mcscmbryanthcmaceac
Asteraceae
Fabaceae
Liliaceae
Iridaceae
Ericaceae
Poaceae
Asclepiadaceae <s.s.)
Scrophulariaceae (s.s.)
Euphorbiacea
Cyperaceae
Orchidaceae
Proteaceae
Acanthaceae
Crassulaceae
Rutaceae
Restionaceae
G eraniaceae
Campanulaeeae (s.s.)
Lamiaceae
Oxalidaceae
Rubiacea
Aizoaceae
Apiaceae
Selaginaceae
Poiygalaceae
Amaryllidaceae
Rhamnaceae
Thymeiaeaceae
Sterculiaceae
Lobeliaccae
Rosaceae
Santalaceae
Brassicaceac
Malvaceae
Chcnopodiaccae
Convoivulaccae
Anacardiaceae
2 Calculated from Goldblatt (1978)
G ood (1974)
'N aturalized taxa
% of
Rank in
endem, 30 largest
spp.* world famsb
98,0
86,0
74,5
88,5
96,5
99,7
44,4
86,9
86,8
79,7
51,8
80,5
97,0
66,4
88,6
94,1
94,1
96,3
92,1
63,1
98,0
52,1
98,0
90,3
97,1
87,5
81,9
92,3
95,0
84,6
(92)
94,0
94,4
91,7
32,0
85,2
29,8
72,0
—
1
3
11
—
21
4
13
8
6
9
2
—
15
—
—
—
—
—
7
—
5
—
17
—
—
—
—
—
—
—
24
—
—
—
—
—
—
B othalia 15, 3 & 4 (1985)
616
Africa are included in G o o d ’s list, but M esem bryanthem aceae and Iridaceae a re not am ong the w orld’s
30 largest families. T he 38 most im portant southern
A frican families include 18 o f the largest families
listed by G ood.
T h e species/genus ratios o f the families can reflect
th eir phytogeographical affinities. T he overall
species/genus ratio for southern A frican seed plants
is ab o u t 9,6. T he families with a species/genus ratio
m ore th an twice the overall ratio are those known to
have diversified extensively within southern Africa
especially in Capensis: M esem bryanthem aceae, Liliaceae, Iridaceae, E ricaceae, P roteaceae, Crassulaceae, R estionaceae, G eraniaceae, C om panulaceae,
O xalidaceae, Selaginaceae, R ham naceae, Thym elaeaceae, Sterculiaceae, Lobeliaceae and Santalaceae. Fam ilies with a species/genus ratio about half
th e overall ratio o f 9,6 a re all families o f worldwide
distribution o r with centres o f diversity in the tropics
o r n o rth tem p erate areas: Poaceae (w orldw ide), Rubiaceae (pantropical), and A piaceae (north tem ­
p erate) (G o o d , 1974).
All the families with a high species/genus ratio
also have m ore than 88% o f th eir species endem ic to
southern A frica. H ow ever, not all families with a
high percentage o f endcm ic species have a high
species/genus ratio. In these exceptions, eith er more
than half the genera in the family are endem ic but
each have a m o d erate num ber o f species (R utaceae,
A piaceae), o r less than a fourth o f the genera in the
family are endem ic but a few genera have a large
num ber o f endem ic species (Brassicaceae — Heliophila, R osaceae — Cliffortia).
In T able 3, the families a re ranked by the num ber
o f species and subspecific taxa. If the num ber o f in­
digenous specics is used fo r ranking instead, there is
little change in th e placing o f the 38 largest families.
C yperaceae and Euphorbiaceae exchange places at
ranks 10 and 11, but th ere is only a difference o f
th ree species betw een them . C rassulaceae falls from
15th to 20th as a result o f the large num ber o f sub­
specific taxa now accepted, and A piaceae falls from
24th to 30th as a result o f the high num ber o f natura­
lized species. Polygalaceae and T hym elaeaceae each
gain th ree places in com parative ranking, mainly b e ­
cause they have few naturalized species o r infraspesific tax a, and therefore th ere is little difference be­
tw een the total num ber o f taxa and the total num ber
o f indigenous species.
The 21 families o f flowering plants with m ore than
20 genera are listed in T able 4. O nly o n e family,
A m aranthaceae, does not also have m ore than 100
species. T he ranking o f the families by num ber of
genera corresponds only roughly co the ranking by
num ber o f species and infraspecific taxa, but th e 12
families with th e most genera include ten o f the larg­
est families ranked by species and infraspecific taxa.
Ericaceae and C yperaceae have com paratively fewer
genera, and Rubiaceae and A piaceae have com para­
tively m ore.
T he families in T able 4 can be divided into three
groups o n the basis o f the percentage o f their genera
that occur in southern A frica related to their world­
wide distribution, (a) T h ree families have from
nearly half to virtually all th eir genera represented in
southern Africa: M esem bryanthem aceae, the most
strongly ‘southern A frican' o f all o u r families; Irida­
ceae, concentrated in the southern hem isphere; and
Ericaceae, with the subfamily E ricoideae present in
E urope but concentrated in southern Africa (G ood,
1974). (b ) All the families w ith a worldwide distribu­
tion described by D yer (1975, 1976) as simply ‘cos­
m opolitan’ have betw een 20 and 40% o f their genera
represented in southern A frica, (c) T he families with
few er than 20% o f their genera occurring in south­
ern Africa are distributed predom inantly in climatic
TA B LE 4. — The 21 families of flowering plants with more than 20 genera ranked by numbers o f genera
Rank Family
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
Asteraceae
Poaceae
Fabaccac
Mesembryanthemaceae
Rubiaccac
Liliaceae
Asclepiadaceae
Scrophulariaceae
Orchidaccae
Euphorbiaceae
Iridaccac
Apiaceae
Acanthaceae
Lamiaceae
Cyperaceae Brassicaceac
Ericaceae
Amaranthaceae
Rutaceae
Aizoaceae
Malvaceae
* D yer (1975, 1976)
’ Naturalized genera
No. genera
in sthn
Africa
180+50'
171+28*
122+13'
123
59+1*
57+2*
58+1*
53+5*
54
43+5*
46+1*
35+7*
41
32+5*
36
15+19*
24
22+2*
20+1*
21
15+6'
No. genera % of genera
worldwide' indigenous
in sthn Afr,
900
660
600
124
500
230
200
170
725
300
75
260
250
170
90
370
50
65
150
•>
75
20,0
25,9
20,0
99,2
11.8
24,7
29,0
31.1
7.4
14.3
61.3
13.5
16,4
18,8
40.0
4,1
48,0
33,8
13,3
—
20.0
Family rank
in sthn Afr,
by spp. &
infrasp. taxa
Worldwide
family
distribution'
2
7
3
1
22
4
8
9
12
10
5
24
14
19
11
34
6
Cosmopolitan
Cosmopolitan
Cosmopolitan
Southern Africa
C os., tropical
Cosmopolitan
C os., subtropical
Cosmopolitan
C o s., absent dry area
C os., tropical
C os., sthn hemisphC os.. tem perate
Trop, & subtrop.
C os., warm temp.
Cosmopolitan
C o s., n o n h em temp.
C o s.. Europe & sthn Afr.
C os., trop. & warm
C o s., warm & temp.
Cosmopolitan
C os., trop. & subtrop.
—
15
23
35
617
B othalia 15, 3 & 4 (1985)
TABLE 5 . — The 35 genera o f flowering plants with m ore than 100 species and infraspecific taxa
Rank
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
Genus
Erica
Ruschia
Conophytum
Aspalathus
Senecio
Euphorbia
Helichrysum
Oxalis
Lampranthus
Indigofera
Pelargonium
Phylica
Delosperma
Aloe
Thesium
Haworthia
Hermannia
Gladiolus
Agathosma
Crassula
Wahlenbergia
Cliffortia
Sutera
Selago
Restio
Drosanthemum
Muraltia
Stapelia
Schizoglossum
Lotononis
Cheiridopsis
Sphalmanthus
Lobelia
Euryops
Disa
No. supp.
& infrasp. taxa
No.
indigen.
spp.
Family
792
372
362
333
323
302
260
241
237
226
219
190
180
175
168
165
155
148
138
137
136
129
128
128
119
119
119
119
117
114
111
111
103
103
101
638
352
301
256
309
266
241
193
218
212
211
147
159
152
166
153
146
107
138
42
135
108
125
127
113
111
116
88
97
104
103
108
81
90
90
Ericaceae
Mesembryanthemaceae
Mesembryanthemaceae
Fabaceae
Asteraceae
Euphorbiaceae
Asteraceae
Oxalidaceae
Mesembryanthemaceae
Fabaceae
Gcraniaceac
Rhamnaceae
Mesembryanthemaceae
Liltaceac
Santalaceae
Liliaceae
Sterculiaceae
Iridaceae
Rutaceae
Crassulaceae
Campanulaceae
Rosaceae
Scrophulariaceae
Sclaginaccac
Restionaceae
Mesembryanthemaceae
Polygalaceae
Asclepiadaceae
Asclepiadaceae
Fabaceae
Mesembryanthemaceae
Mesembryanthemaceae
Lobeliaccae
Asteraceae
Orchidaceae
areas not well represented in southern Africa: Orchidaceae (absent from dry areas), Brassicaceae
(n o rth tem p erate), Euphorbiaccae (tropical), Apiaccae (tem p erate), A canthaceae (tropical and subtro­
pical). A m aranthaceae and R utaceae are excep­
tions. B rassicaceae is notew orthy because over half
its genera in southern Africa are naturalized.
Tw o bryophyte families also have m ore than 20
gen era, P ottiaceae (29) and L ejeuneaceae (28).
The largest genera in the southern African flora
Thirty-five genera in the southern A frican flora
have m ore th an 100 species and infraspecific tax a, as
shown in Table 5. All o f these genera occur in one o f
the 38 largest families, and 22 occur in o ne o f th e 12
families with o ver 500 species and subspccific taxa.
A m ong th e 12 largest families only tw o, Poaceae and
C yperaceae, d o not have a genus with m ore th a n 100
species. A ccording to G oldblatt (1978), only five of
th e large genera are endcm ic, three in M esem bryan­
them aceae (Ruschia, Conophytum and Lampranthus), one in F abaceae (Aspalathus) and one in R u ­
taceae (Agathosma).
N ot surprisingly, the 12 largest families have the
most large genera. M esem bryanthem aceae has 7
genera with o v er 100 taxa, A steraceae and Fabaceae
have 3 each , and Liliaceae and A sclepiadaceae 2
Family rank
in sthn Afr.
by spp. &
infrasp. taxa
6
1
1
3
2
10
2
21
I
3
17
28
1
4
33
4
30
5
15
20
18
32
9
25
16
I
26
8
8
3
1
I
31
1
12
each. T he o th er families each have only a single
genus with m ore than 100 taxa.
Size and composition o f the southern African flora
compared to the floras o f other parts o f Africa
Since 1950, several com plete accounts o f th e flora
o f various parts o f Africa have b een published, cov­
ering the areas shown in Fig. 1. T h e num bers of
taxa, num ber o f vegetation types, cen tres o f en d e­
m ism , and sizes o f each o f these areas can be co m ­
pared to southern A frica, in o rd e r to place o u r flora
into perspective with that o f o th e r parts o f the conti­
nent, and with sm aller areas inside southern A frica.
T he treatm ents considered fo r tropical A frica w ere:
Flora o f West Tropical Africa, 2nd edn (K eay, 1954,
1958; H epper, 1963, 1968, 1972); The flowering
plants o f the Anglo-Egyptian Sudan (A ndrew s 1950,
1952, 1956) and Enumeratio Plantarum Aethiopicae
Spermatophyta (C ufodontis, 1953-1970, as listed by
M eyer, 1973). F or areas w ithin southern Africa, the
following treatm ents were considered: Prodromus
einer Flora von Sudwestafrika (M e rx m iiller,
1966-1970); Flora o f Natal (R oss, 1972); Flora o f
Lesotho (Jacot G uillarm od, 1971); Flora o f Swazi­
land (C om pton, 1966, 1976); Plants o f the Cape
Flora (G oldblatt & B ond, 1984) and Flora o f the
Cape Peninsula (A dam son & S alter, 1950).
618
B othalia 15, 3 & 4 (1985)
w
«
kt
*r
vegetation types and num ber of centres of ende­
mism. Southern Africa has the largest num ber o f fa­
milies, genera, and species plus infraspecific taxa.
A lthough it does not cover the largest a re a , it has the
largest num ber o f vegetation types and centres of
endem ism as m apped by W hite (1983). A lthough the
west tropical A frican flora covers nearly twice the
area o f southern A frica, it has less than a third o f the
num ber o f species and infraspecific taxa as southern
Africa. T he richness o f the southern A frican flora is
further em phasized w hen areas within it are com ­
p ared to areas outside. T he included C ape flora
ranks second in num ber o f species, with at least
1 500 taxa m ore than the third-ranking west tropical
African flora, even though the area covered by the
west tropical A frican flora is m ore than 53 tim es the
area o f the C ape flora. T he included South W est
A frican/N am ibian flora is sim ilar to the Sudan flora
in num ber o f species and infraspecific tax a, even
though S udan has m ore than twice the num ber of
vegetation types and nearly twice the area o f South
W est Africa/Namibia.
T he far larger num ber o f taxa recorded for south­
ern A frica may be ascribed to four factors;
FIG- 1.—Parts o f Africa covered by floras considered in this
study. 1. Flora of West Tropical Africa; 2, the Flowering
Plants o f the Sudan; 3, Enumeratio Plantarum Aethiopicae
Sperm atophyta; 4, List o f Species o f Southern African
Plants; 5. the Flora o f Swaziland; 6 , Flora o f N atal; 7, Flora
o f Lesotho; 8. Plants o f the Cape Flora; 9 , Flora o f the Cape
Peninsula; 10. Prodromus einer Flora von Siidwestafrika.
T ables 6 ,7 & 8 com pare num bers o f fam ilies, g en­
e ra and species plus infraspecific taxa for each o f the
te n floras, and Table 9 shows each o f the floras
ranked by num bers o f taxa, area covered, num ber of
1. southern A frica has the largest num ber o f vege­
tation types o f all the floras considered. N one o f the
vegetation types are shared betw een southern Africa
and the tropical floras north o f the eq u ato r except
the habitat-lim ited and com paratively small aquatic,
halophytic, m angrove and afrom ontane vegetation
types. T he southern A frican vegetation includes the
C ape flora, with over 8 500 species and the karroid
vegetation types, also rich in species,
2. southern Africa has four centres of endemism
(W hite, 1983) and a very high percentage o f endem ic
taxa (G oldblatt, 1978). Tw o o f the centres o f en d e­
T A B LE 6.— Comparison o f numbers o f families in African floras
Tropical floras N. of equator
W trop
Afr.
Sudan
Gymnosperms
Monocotyledons
Dicotyledons
Total seed plants
3
40
159
202
4
32
135
171
Pteridophytes
Total vascular plants
27
229
Included sthn African floras
Entire sthn
Ethiopia Afr. flora Swaziland
Natal
Lesotho
Cape
flora
Cape
Penins.
SWA/
Namibia
3
32
143
178
6
37
163
20«
2
2!
Ill
134
4
34
141
179
0
17
78
95
4
32
116
152
3
19
96
118
1
26
127
154
—
.—
13
147
18
113
—
—
28
234
—
—
11
129
12
166
—
—
TA B LE 7,— Comparison o f numbers of genera in African floras
Tropical floras N, o f equator
Included sthn African floras
en tire sthn
Ethiopia Afr. flora Swaziland
W trop
Afr.
Sudan
Gymnosperms
Monocotyledons
Dicotyledons
T otal seed plants
3
c.368
1 298
I 669
4
255
878
1 137
3
296
1 090
1 389
6
502
1 794
2 302
Pteridophytes
T otal vascular plants
72
1 741
—
—
—
—
74
2 376
Natal
Lesotho
Cape
flora
Cape
Penins.
SWA/
Namibia
2
200
558
760
4
311
918
1 233
0
159
367
526
4
282
700
986
3
209
459
671
1
205
481
687
36
796
—
—
28
554
28
699
16
703
—
—
B othalia 15, 3 & 4 (1985)
619
TA BLE 8.— C om parison o f n u m b ers o f species and infra specific taxa in A frican floras
T ro p ical floras N. o f e q u a to r
W tro p
Afr.
Sudan
G ym nosperm s
M onocotyledons
D icotyledons
T o ta l se e d plants
4
1 810
5 200
7 014
4
817
2 393
3 215
Pteridophytes
T o tal vascular plants
312
7 326
Included sthn A frican floras
E ntire sthn
E thiopia Afr. flora Sw aziland
N atal
L esotho
C ap e
flora*
Cape
Penins.
SWA.'
Nam ibia
4
1 527
4 792
6 323
43
S 129
17 80S
22 977
8
566
1 515
2 089
14
1 304
3 500
4 818
0
485
1 052
1 537
11
2 075
6 418
8 504
6
846
1 713
2 565
1
740
2 384
3 125
__
_
—
273
23 250
73
2 162
_
—
54
1 591
c.75
8 579
57
2 622
43
3 168
—
'S p e c ie s only. B ond & G o ldblatt (1984) did not include infraspecific taxa.
T A B L E 9. — R ankingof floras by num bers o f taxa o f se ed plan ts .a r e a , num ber o f vegetation types and n u m b er o f c e n tre s o f endem ism
R an k
Fam ilies
G enera
Spp. & infrasp.
taxa
A pprox. area
(ktn: )
N o. vegetation
types-'
N o . centres
o f endemism*1
S thn Afr.
206
Sthn Afr.
2 302
Sthn A fr,
22 977
W . tro p , Afr,
4 836 700
Sthn A fr.
28
S th n Afr,
4
2
W trop. Afr.
202
W trop. Afr.
1 669
C ape flora
8 504"
S thn Afr.
2 573 000
W tro p . A fr.
24
W tro p . Afr.
3'.
3
Natal
E thiopia
I 389
W tro p . Afr.
7 014
Sudan
2 505 800
S udan
18
E thiopia
3
178
N atal
I 233
E thiopia
6 323
E thiopia
1 696 450
E thiopia
17
SW A
2
5
Sudan
171
Sudan
1 137
N atal
4 818
SW A
825 200
SW A
10
C ap e flora
2
6
SW A
154
C ape flora
986
S udan
3 215
C ape flora
90 000
N atal
7
Sudan
2
7
C ap e flora
152
Swaziland
760
SW A
3 125
N atal
86 000
C ape flora
4
Natal
1
8
Swaziland
134
SW A
6R7
C ap e Penins.
2 565
L esotho
30 276
L esotho
4
L esotho
1
9
C ap e Penins.
118
C ape Penins.
671
Swaziland
2 089
Swaziland
17 363
Swaziland
3
C ap e Penins.
1
10
L esotho
95
L esotho
526
L esotho
1 537
C ape Penins.
470
C ape Penins.
1
Sw aziland
0
1
179
4
E thiopia
* W hite (1983).
‘ Species o nly. B ond & G oldblatt (1984) did not include infraspecific taxa.
m ism , th e C ape and the K aroo-Nam ib, occur only
within southern A frica (except for a small extension
o f th e K aroo-N am ib into southern A ngola), and al­
though the Z am bezian centre lies mostly outside
southern A frica, it is not covered by any o f the Flo­
ras considered except the List o f Species o f Southern
African Plants. Only the afrom ontane centre of
endemism is shared with other Floras considered.
G oldblatt (1978) estim ates th at 80% o f the southern
A frican species are endem ic, and the levels o f e n d e ­
mism in m any o f the largest families are considerably
higher than 80% , as shown in Table 2. B rcnan
(1978) calculated an area/endem ic index fo r various
parts o f tropical Africa. T his index estim ated for the
w hole o f southern Africa is 161 (i.e, 20 000 x 0,8 =
16 000 estim ated endem ic seed plant species;
2 573 000 km ; -s- 16 000 endem ic species = 161
area/endem ic). This indicates higher levels o f e n d e ­
mism fo r southern A frica than fo r anywhere in tropi­
cal A frica, w here Brenan reports strongest e n d e ­
mism in G abon (239) and C abinda (251). In com ­
parison, he reports that Sudan, w ith a sim ilar area to
southern A frica, has an area/endem ic index o f
50 000. A t the o th er extrem e, the area/endem ic in­
dex calculated for the C ape flora using the figures o f
B ond & G oldblatt (1984) is 15,
3.
the counts fo r the southern A frican flora as a
whole and fo r the C ape flora are o f m ore recent date
than any o f th e others. M any m ore taxa are probably
known fo r each o f the areas now than ap p ear in the
Floras considered, m ost o f which a re o v er ten years
old. F or exam ple, the num bers o f seed plant taxa
reported by Jacot G uillarm od (1971) fo r L esotho
w ere 526 genera and 1 591 species and infraspecific
taxa. A listing from PREC IS o f all L esotho speci­
m ens m ade in 1984 show ed 702 genera and 2 726
species and infraspecific tax a, an increase o f 25%
and 42% respectively in 13 years. Sim ilarly, W hite
(1983) estim ates 8 000 species for the G uineo-Con-
620
B othalia 15, 3 & 4 (1985)
golan cen tre o f endem ism , which form s only a part
o f th e area o f the west tropical A frican flora,
result o f the sam e factors th at give th e Poaceae a
com paratively low ranking in the sam e floras.
4.
the southern A frican flora is being studied pri­
marily by botanists w orking in the region, w hereas
th e floras o f west tropical A frica, Sudan and E thio­
pia have been studied prim arily by botanists working
in E urope. This undoubtedly increases the p ro p o r­
tion o f the existing flora th a t has been collected.
Even within southern A frica, m apping the num bers
o f specim ens per q u arte r degree square has shown
that collecting intensity is greatest in easily acces­
sible locations (G ibbs R ussell, R etief & Sm ook,
1984),
T hree families show differences betw een the m a­
jor com ponents o f the tropical and southern African
floras, A canthaceae and Rubiaceae are am ong the
ten largest families both in the tropical floras north
o f the eq u ato r and in the included floras o f tropical
affinity within southern A frica, nam ely South West
A frica/N am ibia, N alal and Swaziland, Asclepiada­
ceae is the only family th at is a m ajor com ponent o f
all (extra-C apensis) southern A frican floras but not
o f the tropical floras north o f the equator.
T h e individual floras included in the entire south­
ern African area each has only a fraction o f the total
num ber o f taxa in the region, and only a small pro­
portion o f th e 28 vegetation types present in the
whole area. N evertheless, only the th ree karroid ve­
getation types are not covered by at least one o f the
included Floras considered.
T h e ten largest families in each o f the Floras are
com pared in T able 10. All the ten largest families in
the en tire southern A frican flora are also am ong the
largest families in at least one o th er F lora consid­
ered. Each o f th e 24 families concerned is represen­
ted in southern A frica, and only A pocynaceae and
A nnonaceae d o not have o v er 100 species and infraspecific taxa in southern Africa, A m ong the floras
considered, these tw o families are a m ajor com po­
nent only o f th e west tropical A frican flora.
Only tw o families, A steraceae and Fabaceae are
am ong the ten largest in all the floras. A steraceae
ranks first o r second in all the included southern
A frican floras, and if M esem bryanthem aceae were
critically revised (G ibbs Russell & G len , 1984) A s­
teraceae would be the largest family in the entire
southern A frican flora as well. In the tropical floras
A steraceae is not as outstanding, ranking below Fa­
baceae and Poaceae. In contrast, F abaceae is o f first
o r second rank in the tropical floras, but ranks only
from second to fourth in the southern A frican floras.
Poaceae is am ong the ten largest families in all the
floras considered except the C ape flora, and it has a
much lower ranking in southern A frica as a whole
th an in th e tropical floras o r in the included floras o f
southern Africa, N evertheless, in absolute num bers
there are m ore taxa recorded fo r Poaceae in south­
ern A frica than fo r the tropical floras even though
the ranking in southern Africa is lower. This com ­
paratively low er rank for southern A frica as a whole
may result from two factors. Firstly, the many w ide­
spread grass species are counted separately for the
sm aller included floras, but only once for the entire
southern A frican flora. Secondly, th e C ape flora has
a very low num ber o f grasses in com parison to Aizoaceae (s.I.), Liliaceae (s.l.), Iridaceae and Erica­
ceae. T h e large num bers o f taxa in these families in
the C ape flora give the Poaceae a lower ranking in
th e southern A frican flora as a whole, C yperaceae is
th e only family that is a m ajor com ponent o f all flo­
ras considered except the entire southern African
flora and the C ape flora. Its absence from the ten
largest families in these tw o floras is probably the
Lam iaceae shows a difference betw een eastern
Africa and the rest o f the continent. In A frica, this
family has its greatest im portance in eastern Africa,
from Sudan and Ethiopia south to Swaziland and
N atal (w here it ranks 11th).
The families th at are peculiarly southern A frican,
recognized in T able 3 by th eir high species/genus ra ­
tios and percentage o f endem ism , are also clearly
shown in T able 10. A izoaceae, E ricaceae, Iridaceae
and R estionaceae are am ong the ten largest families
in the C ape flora, and through it, o f southern Africa
as a whole. Proteaceae and R utaceae are am ong the
ten largest families only in the C ape flora. Am arvllidaceae and C am panulaceae a re m ajor com ponents
only o f the high-altitude L esotho flora, although
C am panulaceae ranks 11th in the C ape flora. Again,
one family exhibits an opposite p attern: E upho rb ia­
ceae is one o f the ten largest families in all floras ex­
cept the C ape and Lesotho.
Convolvulaceae and M alvaceac arc m ajor com po­
nents of the flora only in Sudan, although they have
m ore than 100 species in southern Africa.
T hree families show patterns o f distribution that
do not coincide with any others. Liliaceae (s.l.) is
one o f the ten largest families in southern and east­
ern A frica, but not o f west tropical Africa and Su­
dan. O rchidaceae, although the sccond largest fam ­
ily in the w orld, is not am ong the m ajor com ponents
of the floras o f South W est A frica/N am ibia, Sudan
o r E thiopia, perhaps because o f the considerable
arid areas in these countries. In C apensis, O rchida­
ceae ranks 12th in the C ape flora as a w hole and 7th
in the C ape Peninsula. Scrophulariaceae is the most
unusual in its areas o f im portance. It is am ong the
ten largest families in the C ape flora (tem perate and
w inter rainfall), South W est Africa/Nam ibia and Su­
dan (both tropical and a rid ). N atal (o f tropical affin­
ity and mesic to arid), and L esotho (high altitude).
Species richness o f the souihern African flora com ­
pared to floras o f other parts o f the world
The richness o f the southern A frican flora com ­
pared to floras o f o th er large regions o f the world,
both tropical and tem perate, is shown in T able 11.
T he species/area ratio fo r the whole o f tropical
Africa is sim ilar to that o f its included parts, Sudan
and west tropical Africa. T he ratio for southern
Africa is ab o u t five tim es as great, illustrating the
com parative poverty o f the tropical African flora
discussed in detail by B renan (1978). Tw o o th er
tropical areas, Brazil in tropical S outh A m erica and
tropical A sia, are widely separated geographically
B othalia 15, 3 & 4 (1985)
621
T A B L E 10. — C om parison o f n um bers o f species and infraspecific taxa in th e 10 largest families in all floras considered. The top num ber is
the rank o f the family in the flora and the b o tto m n u m b er is the n u m b er o f species and infraspeciftc taxa. A d a sh in the top position shows
that th e family is n o t am ong th e ten largest in that flora
Included sthn A frican floras
T ropical floras N o f e q u a to r
W trop.
A fr.
Sudan
E thiopia
slh n Afr.
flora
8
178
7
98
4
273
—
0
—
0
—
(25)
1
2 917
--(17)
—
(19)
__
(205)
10
112
—
(15)
__
(13)
A pocvnaceae
9
132
A sclcpiadaccac (s./.)
A canthaccac
A izoaceae (s./.)
A m aryllidaeeae
A nnonaceae
—(14)
(362)
— (27)
__
03)
Swazi­
land
N atal
L esotho
C ap e
flora3
C ape
Penins.
SW A '
N am ibia
10
64
_
__
(108)
__
(27)
__
0
7
118
—
<9)
—
(39)
—
(6)
--(54)
(6)
--(18)
2
769
9
94
4
191
10
34
--(83)
—
(27)
—
(2)
__
(6)
--0
--(0)
—
0
—
(25)
—
0
—
(6)
—
(!7 )
—
—
(23)
(8)
—
(33)
—
(41)
—
(12)
—
(94)
—
(59)
—
(150)
8
915
5
96
5
207
7
60
—
<135)
—
(I)
—
(21)
A steraccae
6
291
3
208
3
565
2
2 417
1
223
1
546
I
302
1
986
I
292
2
34?
C am panulaceae (s.l.)
—
(27)
—
(16)
—
(36)
—(13)
(454)
—
(21)
—
(75)
9
35
—
(222)
—
(68)
—
(26)
C onvolvulaceae
--(76)
8
77
__
(85)
—(37)
(130)
—
(22)
—
(52)
(13)
5
312
4
152
7
232
—(11)
(487)
7
71
7
168
—
(3)
—
—
(3)
(7)
—
(9)
—
(32)
7
272
6
131
6
235
10
506
1
725
I
390
2
659
3
1 802
—
(9)
—.
(27)
1 024
9
74
5
242
—
(57)
8
220
—
(78)
—
(71)
->
10
152
612
387
C yperaceae
E ricaccac
E uphorbiaceae
F abaceae (s.l.)
Iridaceae
L am iaceae
L iliaceae [s.l.)
M alvaceae
__
(15)
—,
(% )
—
(65)
Poaceae
1
704
6
122
—
(15)
3
672
8
119
—
0
—
420
4
644
2
191
1
264
__
(36)
—
(92)
10
34
5
612
4
154
—
(23)
9
68
__
(U 7 )
__
(26)
.—
(44)
—
(15)
—
(47)
4
122
4
226
5
83
6
419
6
123
5
139
— (35)
(161)
—
(28)
—
(60)
—
(13)
—
(27)
—
(13)
—
(56)
7
3
173
3
410
2
170
—
(181)
3
181
I
344
-(1 3 )
392
—
m
—
(16)
—
(4)
7
320
—
(47)
-—(12)
(480)
6
77
6
206
8
54
—
(206)
7
121
(0
—
(9 )
—
—
8
310
10
86
—
0
—
(54)
—
(16)
—
(41)
10
259
—
(23)
—
(3)
—
(60)
(100)
5
— 119>
(257)
4
1 142
955
—
(49)
R estionaceae
—
0
—
0
—
0
—<16!
(301)
R ubiaceae
3
557
5
152
9
204
R utaccae
—
(28)
—
(9)
—
(23)
Scrophulariaceac
—
(93)
1(1
64
—
(133)
51
5
133
10
89
4
403
• c/c o f to ta l flora
(seed p lan ts) in
10 largest families
—
(44)
—
(?35)
O rchidaceae
T o tal no. sp p . & infrasp. taxa
3 594
in 10 largest families
—
(9)
6
83
(IS )
—
(203)
—
(98)
—
(3)
(!)
—
(123)
—
8
114
(I? )
4
94
—
(6)
Protcaccae
—
6
984
—
(->>
—
(10)
8
70
2
179
8
146
2
—
(6)
—(22)
(236)
(!)
—
(62)
9
130
(1)
—
(18)
—(16)
306
—
(8)
—
(13)
—
(2)
—
(53)
10
127
3
121
9
310
9
786
—
9
1 733
3 486
13 468
1 143
2 586
1 070
5 301
I 494
I 822
54
55
59
55
54
69
62
58
58
“Spccies only. B ond & G oldblatc (1984) did not include subspecific taxa.
B othalia 15, 3 & 4 (1985)
622
T A B L E 11. — Species/area ratios for several rceions o f the w orld w ith area s o f over
± 2 500 « 0« km ;
R egion
T ropical A frica
W est tropical Africa
Sudan
Brazil
India, P akistan,
B angaladesh. Burm a
A ustralia
E astern N orth A m erica
S outhern Africa
S outhern Africa
(excluding C apensis)
N o. species
A rea (km -)
Species/A rea
30 000»
7 300
3 200
40 000“
20 (X10 000
4 500 000
2 505 800
8 456 500
0.0015
0,0016
0.0013
0,0047
20 000"
25 OOO4 42Sd
20 000
4
7
3
2
885 280
716 000
238 000
573 (XK)
0,0041
0.0032
0.0014
0.0078
14 200'
2 483 000
0.0057
aB renan (1978).
bG o o d (1974).
‘Ride (1978) q u o ted in G oldblatt (1978).
dG o ldblatt (1978).
‘C alculated from G ibbs Russell ei at. (1984) a n d B ond & G o ldblatt (1984),
but have sim ilar species/area ratios. A lthough tropi­
cal areas are known to have high concentrations o f
species, the species/area ratio fo r southern Africa is
about 1,7 tim es greater than either. T he A ustralian
flora is som etim es com pared to that o f southern
Africa because both are southern hem isphere areas
with tropical and tem perate vegetation elem ents and
both have high levels o f endem ism . H ow ever, the
species/area ratio for southern A frica is nearly 2,5
tim es that o f A ustralia. T he ratio for eastern N orth
A m erica, in the north-tem perate zone, is also far b e ­
low that o f southern Africa. Even if the extrem ely
diverse C ape flora is elim inated from the determ ina­
tion o f th e species/area ratio for southern A frica, the
ratio is nevertheless higher than that fo r tropical
South A m erica o r Asia.
Size and composition o f the southern African flora
reported in the List o f Species compared to previous
recent treatments
T able 12 shows the num bers o f genera and species
recorded for each family in the List o f Species
(1984), D yer (1975, 1976) and G oldblatt (1978). Fa­
milies th at are trea ted differently in the three
sources are shown both sensu stricto and sensu lato
so that com parisons can be m ade. For seed plants,
the count o f G oldblatt and the estim ate based on
D yer agree within 50 species. T hey d a te from the
sam e p erio d , but D yer’s w ork was carried out pri­
marily at P R E . w hereas G oldblatt’s count was d e te r­
mined from several herbaria, literature, and consul­
tation with experts in various groups. T h e closeness
o f the final count confirm s b oth as being reasonable
determ inations for th at time.
T he List o f Species count is about 215 indigenous
genera and 1 450 species higher than G o ld b latt’s
count. T his discrepancy is the result o f different
num bers o f species recorded in a num ber o f families,
For 63 families (30% o f the num ber o f families of
seed plants) th e List o f Species has a higher num ber
o f species th an eith er o f the o th er counts, and 27 fa­
milies exceed D yer’s and G oldblatt’s counts by m ore
th an 5 species. O ver a third o f the species are in Mesem bryanthem aceae, which has been previously
m entioned as having in reality far fewer species than
are presently recognized. T h ree o th e r families differ
by m ore than 100 species, A sclepiadaceae, F abaceae
and Liliaceae. In each o f these fam ilies, certain gen­
era are under revision but others are still in need o f
treatm ent. G oldblatt’s count has only th ree families
for which the highest num ber o f species is recorded,
O rchidaceae, R estionaceae and R ubiaceae. All
three o f these families have had recent changes in
species num bers as a result o f taxonom ic revision.
A lthough D yer’s estim ate has the lowest total
num ber o f species, curiously there are 15 families for
which his species counts are the highest. Tw o o f
these fam ilies, A steraceae and C rassulaceae, differ
from the List o f Species by m ore than 100 species. A
num ber o f genera in A steraceae and the whole of
Crassulaceae have been revised since 1975. Simi­
larly, Poaceae and Sterculiaceae are recorded with
over 50 species m ore by D yer, but w ork done for the
F T E A (C layton & R envoize, 1982) and a m ore accu­
rate determ ination o f naturalized species has re­
duced species num ber in Poaceae and revisionary
work in Hermannia has reduced species num bers for
Sterculiaceae,
It appears therefore, th at differences in counts of
species in a num ber o f families are due to revisions
com pleted o r in progress betw een the tim e o f com ­
pletion o f D yer, G oldblatt and the List o f Species.
H ow ever, the substantially higher counts in the List
o f Species for A piaceae, C henopodiaceae, C yperaceae, E uphorbiaceae, F abaceae, Liliaceae and Scrophulariaceae cannot be solely a ttrib u ted to th e result
o f further study in these families. F urtherm ore, even
though revisionary w ork has resulted in a lower
count o f species in families such as Poaceac and
C rassulaceae, and in such genera as Helichrysum,
w here 283 taxa (260 species) w ere recognized at
P R E in 1981, but only 260 taxa (241 species) w ere
recognized after H illiard’s treatm ent o f the genus for
the Flora o f Southern Africa, revision does not
necessarily result in the recognition o f a sm aller
num ber o f species. T he revision o f Asparagus cu r­
rently being com pleted for the Flora now recognizes
tw o genera and 77 species w here previously one
genus with 44 species was recognized (A . A. O berm eyer, pers. com m ,). C . H . Stirton (pers. com m .)
predicts th at there may be ultim ately a total o f 2 000
B othalia 15, 3 & 4 (1985)
623
TABLE 12.— Comparison o f numbers o f taxa per fam ily. Families are listed alphabetically w ithin each g ro u p (B ry o p h y ta. Pteridophyta, Gymnospermae, Angiospcrmae). The difference between counts in the List o f S pecics (1984), D yer (1975, 1976) and
G oldblatt (1978) is indicated when there is a difference o f m ore than 5 species. N aturalized fam ilies and genera are indicated
by an asterisk. This table runs from p.
to p.
List o f Species (1984)
Fam ily
B ry o p h y ta
A crobolbaceae
A delanthaceae
A m blystegiaceae
A ndreaeaceae
A neuraceae
A ntheliaceae
A nthocerotaceae
A rchidiaceae
A rnelliaceae
A ulacom niaceae
A ytoniaceae
Bar tram iaceae
Brachytheciaceae
B ryaceae
B ryobartram iaceae
C alym peiaceae
C alypogejaceae
C ephaloziaceae
CephalozieUaceae
Cleveaceae
C odoniaccae
C ryphaeaceae
Dicranaceae
D itrichaceae
Encalyptaceae
E nto d o n taceae
Ephem eraceae
E rpodiaccae
Eustichiaceae
E xorm othecaceae
Fabroniaceae
F issidentaceae
Fontinalaceae
Funariaceae
G igasperm aceae
G rim m iaceae
G ym nom itriaceae
H ed wig iaceae
Herbertaiceae
H ookcriaceae
H ylocom iaceae
H ypnaceae
Jubulaceae
J ungerm an niacea e
Lejcuneaceae
L em bophyllaceac
Lepicoleaceae
L epidoziaceae
Leskcaceae
L eucodontaceae
L ophocoleaceae
Lunular iaceae
M aichantiaceae
M eteoriaceae
Metzgeriaceae
Mn iaceae
M onocarpaceae
N anobryaceae
Neckeraceae
O rthotrichaceac
O xym itraceae
Pallaviciniaceae
Phyllogoniaceae
Plagiochilaceae
Plagiotheeiaceae
G enera
3
2
6
1
1
1
2
1
1
1
4
6
5
10
1
4
1
2
1
I
1
2
14
7
1
4
1
2
1
1
6
1
1
6
3
3
3
4
1
9
1
5
1
7
28
1
1
9
4
3
3
1
2
S
1
1
1
1
Species &
infrasp.
taxa
4
3
8
4
9
1
7
11
3
I
12
17
13
43
1
10
5
5
13
1
8
2
42
14
2
12
3
4
1
3
12
30
1
13
3
8
4
4
1
12
2
20
15
21
64
I
3
20
9
Dyer (1975,76)»
Indigen.
species
4
3
8
4
9
1
7
11
3
1
12
17
13
43
1
10
5
5
13
1
8
2
42
14
2
12
3
4
1
3
12
30
1
13
3
8
4
4
1
12
2
20
15
21
64
1
1
20
9
4
4
12
1
6
12
1
6
5
5
13
1
1
13
1
1
1
!
7
27
7
27
1
3
1
6
1
17
1
6
1
17
2
8
8
4
6
1
2
G enera
Species
G oldblatt (1978)
G enera
-
-
-
-
-
-
-
-
■
Species
•
•
-
-
-
-
-
-
-
•
■
-
*
-
•
*
D ifference
624
B othalia 15, 3 & 4 (1985)
List o f Species (1 9 8 4 )
Fam ily
Polytrichaceae
Porellaceae
Pottiaceae
Prionodontaceae
Pterobiyaeeae
Ptychom itriaceae
Racopilaceae
Radulaceae
R habdoweisiaceae
R hachitheciaceae
Rhizogoniaceae
Ricciaceae
Riellaceae
Schist ochilaceae
Seligeriaceae
Sem atophyllaceae
Sphaerocarpaceae
Sphagnaceae
Splachnaceae
Taïgioniaceae
Thuidiaceae
T rachypodaceae
W aidiaceae
Pteridophyta
A diantaceae
Aspidiaceae
Aspleniaceae
A thyriaceae
Azollaceae
Blechnaceae
C yatheaceae
Davalliaceae
D ennstaedtiaceae
Equisetaceae
Gleicheniaceae
Gram m itidaceae
Hym enophyllaceae
Isoetaceae
Lindsaeaceae
Lom ariopsidaceae
Lycopodiaceae
M aiattiaceae
Marsiliaceae
Ophioglossaceae
Osm undaceae
Polypodtaceae
Psilotaceae
Salviniaceae*
Schizaeaceae
Selaginellaceae
T helypteridaceae
V ittariaceae
G ym nosperm ae
Cupressaceae
Pinaceae*
Podocarpaceae
Stangeriaceae
W elwitschiaceae
Zamiaceae
Angiospermae
A eanthaceae
Achariaceae
Aizoaceae (S.i.)
Aizoaceae (s.1.)
(see M esem bryanthem aceae)
A lism ataceae
A m aranthaceae
A m aryllidaceae
Anacardiaceae
G enera
4
1
29
1
4
2
1
1
1
1
2
1
1
1
1
1
1
6
2
1
9
10
2
5+1*
1
2
1
4
1
2
2
1
1
1
1
1
1
2
6+1*
1
1*
4
1
2+1*
1
1
1•
1
1
1
1
41
3
21
(1 4 4 )
4+1»
22+2*
17
10+4*
Species &.
infrasp.
taxa
Indigen,
species
G enera
Species
-
.
-
-
.
_
_
_
.
.
.
.
.
.
.
_
_
.
.
.
-
G enera
Species
-
12
5
73
1
6
9
2
9
2
1
2
37
S
2
1
11
1
9
1
5
9
2
1
12
5
73
1
6
9
2
9
2
1
2
37
5
2
1
11
1
9
1
5
9
2
1
63
22
32
6
3
10
2
6
6
1
3
2
11
11
1
9
10
1
16
8
2
15
1
1
7
6
12
1
52
22
29
5
2
7
2
4
6
1
3
2
11
11
1
9
9
1
16
8
2
13
1
0
7
6
11
1
3
2
4
1
I
28
3
0
4
1
1
28
1
1
1
1
1
1
3
0
4
1
1
30
351
3
184
2592)
43
3
22
(144)
353
4
172
(2 4 7 6 )
6
55
198
105
4
23
16
13
4
52
221
93
362
3
233
(2 917)
6
81
205
120
G oldblatt (1978)
Dyer (1 9 7 5 ,7 6 )a
_
.
.
-
_
-
.
.
.
.
.
.
,
-
*
.
.
.
-
.
.
.
.
.
.
-
.
.
.
«
-
-
-
.
D ifference
.
_
.
-
I
.
3
1
1
1
1
4
1
1
25
41
3
355
3
135
2021
3
20
17
10
3
53
199
93
.
SL (+571)
D (+23)
SL (+12)
B oth alia 15, 3 & 4 (1985)
625
List o f Species (1984)
Fam ily
A nnonaceae
A piaceae
A pocynaceae
A ponogetonaccae
A quifoliaccae
A raceae
Araliaceae
A iecaceae
A ristolochiaceae
A sclepiadaceae (s.s)
Asclepiadaceae (s.1. )
(see Pcriplocaceae)
A stcraceac
B alanitaceae
B alanophoraceae
Balsam inaceae
Basellaceae
B egonia ceae
Bignoniaceae
B om ba caceac
B oraginaceae
Brassicaceac
Brunlaceae
B urm anniaceae
Burscraceae
B utom aceae
Buxaceae
C abom baceae
C actaceae
C allitrichaceae
C am panulaceae (s.s.)
C am panulaceae ( i f .)
(see L obeliaceae)
C aneliaceae
C annabaceae*
C annaceae*
C appaiaceae
C aryophyllaceae
C asuartnaceae*
C elastraccac
C eratophyllaceae*
C henopodiaceae
C lusiaceae (s.s.)
C lusiaceae (s.l.)
(see Hypericaceae)
C om bretaceae
C om m elinaceae
C onnaraccae
Convolvulaccae
C ornaceae
C rassulaccae
C urcurbitaceae
C unoniaceac
C yperaceae
Dicbapetalaceae
Dioscoreaceae
Dipsacaceae
Droseraceae (s.s.)
Droseraceae (s./.)
(sec R oridulaccae)
E benaceae
E latinaceae
Ericaceae
E riocaulaceae
E rythroxylaceae
Escalloniaceae
E uphorbiaceae
F abaceae
F lacourtiaceae
Flagellariaceae
Frankeniaceae
Fum aria ceae
D yer (1 9 7 5 .7 6 )a
Species &
infrasp.
laxa
Indigen,
species
G enera
Species
13
221
41
9
1
18
11
6
2
892
(9 1 5 )
13
176
38
7
1
16
11
6
1
769
(7 9 0 )
7
37
17
1
1
5
3
5
1
54
(6 1 )
14
142
39
5
1
12
10
6
2
700
(725)
180+50*
1
2
1
1+1*
1
6
1
13+3*
15+19*
12
1
1
1
1
1
1+3*
1
12
18
2417
4
4
S
2
6
11
1
105
171
78
1
33
1
2
1
13
3
273
454
2116
4
4
S
1
6
11
1
92
113
77
1
33
1
2
1
1
3
256
397
206
1
2
1
2
1
6
1
15
33
12
1
1
1
1
3
1
13
18
2 335
3
4
4
1
8
11
1
85
117
76
1
20
1
1*
1*
8
8+ f*
1*
12
1*
13+2*
2
1
1
2
63
66
1
59
1
150
11
1
0
0
50
39
0
56
0
129
9
1
1
1
0
5
7+1*
2
14+1«
I
5
18
2
36
2
1
2
3
49
41
2
130
1
246
77
2
487
3
22
23
G enera
8
35+7*
16+2«
1
1
6
3
5
1
58+1*
(66+1*)
2
2
24
2
2
1
43+5*
122+13*
13
1
1
4*1.
G enera
8
32
16
1
1
5
3
5
1
60
174
1
2
1
1
1
1
13
15
12
1
1
-
2
1
1
3
257
397
1
1
1
1
18
1
Species
13
155
39
7
1
13
11
6
1
605
2072
3
3
4
1
5
11
1
81
109
75
1
31
2
1
1
2
380
12
12
1
2
1
49
40
58
108
2
8
-
2
47
47
0
64
1
80
10
21
41
36
2
107
1
115
72
2
464
3
20
23
1
21
5
8
2
15
!
9
17
2
33
2
1
2
2
3
35
2S
2
107
1
261
69
2
385
4
18
18
19
21
5
6
2
15
1
5
17
2
30
2
1
2
2
3
35
28
2
94
1
219
67
2
421
3
17
24
19
21
51
12
984
14
6
1
526
1 802
26
1
3
8
35
11
804
13
6
1
461
1540
26
1
3
7
2
2
24
2
2
1
48
133
13
1
1
S
40
12
792
11
5
1
384
1 378
28
1
3
6
2
2
24
2
2
1
41
115
13
1
1
-
34
11
799
11
5
1
389
1 495
25
1
3
-
-
-
-
G o ld b latt (1978)
8
17
1
12
1
14
-
8
8
.
Diffcrcnce
SL (+34)
SL (+185)
D (+219)
SL (+11)
S L (+ 1 7 )
D (+ S )
D (+8)
SL (+49)
S L (+ « )
SL (+11)
SL (+13)
D (+146)
SL (+79)
SL (+77)
SL (+162)
626
Bothalia 15, 3 & 4 (1985)
List o f S pecies (1984)
Fam ily
Geissolom aceae
G entianaceae
G eraniaceae
G esneriaceae
G oodeniaceae
Greyiaceae
G rubbiaceae
G unneraceae
H aem odoraceae
Haloragaceae (s.S.)
Haloragaceae (s. 1.)
(see G unneraceae)
Ham am elidaceae
Hernandiaceae*
H ydnoraceae
H ydrocharitaceae
H ydrophyltaceae
H ydrostachyaceae
H ypericaceae
H ypoxidaceae
Icacinaceae
lllecebraceae
Iridaceae
Juncaceae
iuncaginaceae
Lam iaceae
Lauraceae
L ecythidaceae
L em naceae
Lentibulariaceae
Liliaceae
Linaceae
Loasaceae
Lobeliaceae
Loganiaceae
L oranthaceae (s.s.)
L oranthaceae (s.l.)
(see Viscaceae)
L ythraceae
Malphigiaceae
Malvaceae
M artyniaceae*
M elastom ataceae
Meliaceae
M elianthaceae
M enispermaceae
M esem bryanthem aceae
M ontiniaceae
Moraceae
M oringaceae
M usaceae (s. s.)
M usaceae (s.1.)
(see Strelitziaceae)
M yoporaceae*
M yricaceae
M yrotham naceae
Myrsinaceae
M yrtaceae
N ajadaceae
N yctaginaceae
N ym phaeaceae
O chnaccae
O lacaceae
Oleaceae
Oliniaceae
O nagraceae
Opiliaceae
O rchidaceae
O robanchaceae*
O xatidaceae
Papaveraceae
G enera
1
11
5
2
1
1
I
-
Species &
infrasp.
taxa
1
90
279
52
2
3
6
3
1
76
267
44
2
3
3
Species
G enera
Species
5
12
3
1
65
265
47
2
3
4
1
12
4
5
1
7
5
2
1
1
1
1
4
2
3
1
62
271
43
2
3
3
1
12
3
4
t
1
1
4
2
1
4
1
3
11
2
1
5
3
5
43
3
1
37
5
1
6
2
60
2
1
5
5
91
6
8
879
38
2
256
12
1
9
16
949
6
1
141
22
1
1
1
4
1
1
1
6
3
4
44
3
1
31
4
1
6
2
54
2
1
.
5
3
1
3
11
2
1
7
83
6
9
846
19
2
225
11
1
9
18
907
6
1
.
24
.
54
-
12
-
-
G enera
1
10
5
2
1
1
1
1
4
2
3
-
4
G o ld b latt (1978)
D yer (1 9 7 5 ,7 6 )a
Indigen.
species
1
1»
1
4
1+1*
1
6
3
3+2*
46+ 1*
3
1
3 2 -« «
4+1 *
1
4
2
57+2*
2
1
6
5
11
12
3
I
3
11
3
1
3
0
3
11
2
1
86
6
13
1024
23
2
257
13
1
10
20
1 142
5
1
181
24
42
61
•
80
6
7
858
20
2
225
12
1
10
19
1 066
5
1
141
24
40
58
6+1*
3
15 -* *
2*
4
7+2*
2
7+1*
123
1
4
1
1
2
49
17
161
2
11
17
13
15
2684
1
28
1
1
6
1*
1
1
4
4+3*
1
4+1*
1
2
2
5
1
2+2.
1
54
1»
2
1+2.
2
9
1
8
29
3
16
4
15
4
27
4
34
1
480
2
243
7
-
•
-
-
2
48
12
43
13
139
0
9
14
13
13
2408
1
28
1
1
6
7
3
21
]
4
9
2
7
122
1
4
1
1
2
27
12
116
0
9
15
12
14
2 304
1
27
1
1
6
7
3
14
4
6
2
7
0
9
I
8
24
3
10
4
14
2
22
4
12
1
439
0
195
1
1
1
1
4
6
1
5
1
2
2
5
1
4
1
54
1
2
2
0
9
1
7
21
3
11
4
11
3
22
3
11
1
439
1
?200
1
35
13
122
D ifference
SL (+14)
D (+ 11)
D (+21)
D (+ 18)
D (+31)
SL (+ 159)
SL (+16)
SL (+23)
-
9
12
14
13
.
-
1
4
1
1
2
-
1
27
1
1
6
.
1
1
4
4
1
4
1
2
2
5
1
3
1
54
9
1
7
8
3
10
4
13
3
22
4
11
1
461
2
5
203
7
.
S L (+16)
G (+ 22)
627
B othalia 15, 3 & 4 (1985)
Fam ily
Passifloraceae
Pedaliaceae
Penaeaceae
Peripiocaceae
Phytolacca ceae
Piperaceae
Pittosporaceae
Plantaginaceae
Plum baginaceae
Poaceae
Podostem aceae
Polygalaceae
Polygonaceae
P ontederiaceae
P ortulacaceae
P otam ogetonaceae
P rim ula ceae
P roteaceae
Ptaeroxylaceae
Punicaceae*
Rafflesiaceae
R anunculaccae
Reseda ceae
R estionaceae
R etziaceae
R ham naceae
R hizophoraceae
R oridulaceae
Rosaceae
R ubiaceae
R uppiaceae
R utaceae
Salicaceac
Salvadoraceae
Santalaceae
Sapindaceae
Sapotaceae
Sctophulariaceae
Selaginaceae
Sim aroubaceae
Solanaceae
Sphenocleaceae
Sterculiaceae
Stilbaceae
Strelitziaceae
Tam aricaceae
Tecophiliaceae
T hym elaeaceae
Tiliaceae
T rapaceae
Trim eniaceae (also M onim iaceae)
T urneraceae
T yphaceae
Ulm aceae
U rticaceae
V ahliaceae
V alerianaceae
V elloziaceae
V erbenaceae
V iola ceae
Viscaceae
V itaceae
X yridaceae
ZannicheUiaceae
Zingiberaceae
Zosteraceae
Zygophyllaceae
TO TA L
(seed plan ts only)
List o f Species (1984)
Indigen.
G enera
Species &
infrasp.
species
taxa
4+1»
8
7
8
2+1»
2
1
1
3
171+28»
4
4
4+4*
3+1»
5
1
3
13+1»
I
1*
1
7
l+ l*
12
1
8
4
13+4*
59+1»
1
20+1*
1+1»
2
6
13
7
53-«5*
10
1
4+5*
1
7
5
1
1
2
9
4
1
1
4
1
3
11+1«
1
2
2
10+3*
3
1
5
1
5
2
I
8+1*
2076
+ 226»
28
43
26
23
7
5
3
11
27
955
5
210
49
5
65
7
8
392
1
1
2
30
5
301
1
203
8
180
236
2
306
10
4
178
29
14
568
218
3
98
1
186
12
5
3
10
199
61
2
1
11
2
5
28
7
2
9
78
10
19
55
7
5
4
1
55
22647
18
34
21
21
5
5
3
4
24
783
5
205
35
3
64
7
8
366
1
0
2
24
3
282
1
159
8
150
207
2
291
6
3
176
29
14
543
214
3
68
1
175
12
5
2
8
189
56
1
1
10
2
5
24
2
2
9
60
9
18
52
7
5
3
1
53
19776
+ 204#
D yer (1 9 7 5 ,76)a
G enera
Species
4
8
7
7
3
2
1
1
3
192
4
4
6
3
5
1
3
14
1
1
7
2
12
1
8
4
1
16
58
1
21
2
2
6
13
7
53
9
1
6
1
6
5
1
1
2
9
4
1
1
4
1
3
12
I
2
2
13
3
5
1
4
1
1
7
1853
16
30
21
25
4
6
1
10
23
840
4
207
32
3
62
7
8
365
1
.
3
25
2
193
1
173
8
2
145
232
2
270
5
3
163
25
13
495
206
3
50
1
229
10
5
1
10
165
48
1
1
8
1
5
26
1
2
7
67
8
49
10
5
2
1
62
18369
G oldblatt (1978)
G enera
Species
D ifference
6
13
7
51
10
1
3
1
6
5
1
2
8
4
1
4
1
3
11
1
2
2
9
3
5
1
4
1
1
7
17
29
21
5
6
1
10
21
743
4
201
31
3
56
7
7
336
1
3
25
3
316
1
156
8
2
133
234
2
271
5
3
144
23
14
515
210
3
59
1
169
13
1
10
179
49
1
9
1
5
27
2
2
9
55
8
48
10
5
2
1
46
1859
18327
4
8
7
•
2
2
1
1
3
169
4
4
4
3
5
1
3
14
1
1
7
1
12
1
9
4
1
9
59
1
23
1
2
D & G (+6)
D (■♦57)
S L (+ 8 )
SL (+30)
G (+ 34)
D (+14)
S L (+17)
G (+ 27)
SL (+21)
SL (+ 32)
SL (+48)
SL (+ 18)
D (+ 54)
S L (+24)
S L (+8)
D (+7)
D(-*9)
* D yer (1 9 7 5 , 1976) o m itte d species c o u n ts fo r a num ber o f genera. T hese w ere estim ated fro m PRECIS lists d a tin g from th o se years.
* N aturalized genera
* U ndescribed species
B othalia 15, 3 & 4 (1985)
628
species in F abaceae, an increase o f ab o u t 400 species
in this family,
C O N C L U S IO N S
T h e num ber o f species o f seed plants estim ated for
th e southern African flora has increased by roughly
2 300 in th e past fourteen years. T he question arises
w h ether the present to tal, based o n the List o f
Species o f Southern African Plants (1984) will be just
as quickly o u td ated . T h ere are th ree sources of
changes in the num bers o f recognized taxa: lumping
and splitting o f presently recognized taxa, which can
eith er increase o r decrease the total; ‘finding’ taxa in
the H erbarium as a result o f correctly identifying
existing specim ens as undescribed taxa o r as records
o f taxa not previously known from southern Africa,
which will increase the total; and collecting new o r
new ly-recorded taxa in the field, which will also in­
crease the total.
T h e present trend in taxonom y is generally tow ard
reduction in th e num ber o f species recognized (B ren an, 1978). C ertain fam ilies, particularly M esem ­
bryanthem aceae, are likely to have th eir num bers o f
taxa greatly reduced w hen they are critically revised.
T h ere could be a reduction o f over 1 000 taxa in M e­
sem bryanthem aceae alone. H ow ever, the cases of
Asparagus and F abaceae show th a t although there
may be a general trend tow ard reduction, and great
reductions in som e fam ilies, not every group will
have its num ber o f taxa reduced w hen it is revised.
T he num bers o f unpublished species and taxa
given in T ables 1 and 2 are only those which are so
well know n that they have a 'm anuscript nam e'
awaiting publication, and they account fo r only
1,4% o f th e to tal num ber o f known taxa. O bser­
vation o f th e P R E herbarium shows th at th e re a re a
great m any specim ens in ‘sp p .’ folders which await
critical work by experts, and m any will probably
prove to be new o r new ly-recorded taxa. D oubtless
th e sam e situation exists in o th er herbaria w ith large
holdings o f southern A frican plants. Even if only
o n e genus in ten contains a new species, th ere could
be a fu rth er 250 species now represented by H erbar­
ium specim ens.
O verall, southern A frica is reasonably well cov­
ered by plant collections. P R E C IS records show that
every whole degree square has som e specim ens re ­
corded, and since the P R E C IS records represent
only about 16% o f th e total o f H erbarium specim ens
in southern A frica, th e true coverage is probably
b e tte r th an the sam ple shown by P R E C IS (G ibbs
Russell, R etief & Sm ook, 1984). N evertheless, the
arid central and w estern parts o f southern A frica re ­
quire m uch greater collecting efforts in o rd e r for
their plants to be as well represented in herbaria as
those o f the m ore mesic south and east. B ecause o f
th e low er collecting intensity in the dry areas, it is
likely th at th ere are m ore new taxa aw aiting discov­
ery th ere th an in the better-know n mesic areas.
For these reasons, changes in the num bers o f taxa
known for th e southern A frican flora are bound to
occur as a result o f the basic taxonom ic activities o f
plant collecting, herbarium curatioo and revision. In
th e fu tu re, these changes can be easily m onitored
and recorded by updating the List o f Species in P R E ­
C IS, so th at com plete o r partial lists can be printed
by com puter, and to tal num bers determ ined. T he
total now recognized is so large th at even a change o f
1 000 taxa represents only 4% o f the total flora. T he
com parisons m ade here thus may change in detail,
but the overall perspective is unlikely to alter.
T h e com parative picture outlined here em phasizes
the richness o f the southern African flora in term s of
high species/area ratios, many vegetation types and
high levels o f endem ism , especially in som e o f the
largest families and genera. T his richness is unequal­
led anyw here else in the w orld on a subcontinental
scale, and dem ands th a t a high priority be given to
the system atic study necessary to understand it.
ACKNOW LEDGEM ENTS
Mrs W, Roux has patiently checked and proofread
all taxon counts from the List o f Species. D r O . A.
Leistner, D r P . G oldblatt and M r E . G . H. O liver
have m ade valuable criticisms o f th e m anuscript.
U lT T R E K SE L
Die flora van Suider-Afrika is vir die eerste keer tot
by spesies vlak in die List o f Species o f Southern
African Plants (Gibbs Russell et al., 1984) ondersoek. Die aantal taksa wat vir Suider-Afrika opgeteken is word vergelyk met dié van taksa wat vir ander
dele van Afrika aangegee is, en die grootste families
in elke streek word gelys en vergelyk. Die rykdom
van spesies in Suider-Afrika word m et dié van ander
dele van die wêreld vergelyk. Die aantal genera, spe­
sies en subspesies vir elke familie in die Suider-Afrikaanse flora word gegee net met vorige tellings deur
Dyer (1975, 1976) en Goldblatt (1978) vergelyk.
REFEREN CES
A D A M S O N . R . S ., 1938. The vegetation o f South Africa. L on­
d o n : W hitefriars Press.
A D A M S O N , R . S, & S A L T E R . T , M ., 1950. The flowering
plants o f the Cape Peninsula. C ap e T ow n: Juta.
A N D R E W S . F, W „ 1950. The flowering plants o f the AngloEgyptian Sudan. Vol. 1, A rbroath: Buncle.
A N D R E W S , F . W ., 1952. The flowering plants o f the AngloEgyptian Sudan, Vol. 2. A rb ro a th : Buncle.
A N D R E W S , F. W ., 1956. The flowering plants o f the AngloEgyptian Sudan, Vol. 3. A rb ro a th : Buncle.
B R E N A N , J . P. M ,, 1978. Som e aspects o f the phytogeography
o f tropica! A frica. Ann. Mo. bot. Gdn 65: 437-478.
C L A Y T O N , W . D . & R E N V O IZ E . S .A ., 1982. Poaceae. In R.
M , Polhill, Flora o f Tropical East Africa. R o tterd am : Bal­
kem a.
C O M P T O N , R. H ., 1966. A n a n n o ta te d check list o f th e flora o f
Sw aziland. Jl S. A fr. Bot. Suppl, 6.
C O M P T O N . R , H ., 1976. T he flora o f Sw aziland. / / S. A fr. Bot.
Suppl. 11.
D Y E R . R. A ., 1975. The genera o f southern African flowering
plants, V ol. 1, Dicotyledons. P reto ria: G overnm ent Printer.
D Y E R , R . A ., 1976. The genera o f southern African flowering
plants, Vol. 2, Monocotyledons. P reto ria: G overnm ent
Printer.
G IB B S R U S SE L L , G . E ., 1975. C om parison o f the size o f vari­
o u s A frican floras. Kirkia 10: 123-130.
G iB B S R U S S E L L , G . E . & T H E S T A F F O F T H E N A T IO N A L
H E R B A R IU M , 1984. List o f species o f sou th ern A frican
plan ts. Mem. bot. Surv. S. A fr. 48.
G IB B S R U S S E L L , G . E . & G L E N , H . F ., 1984. R egister of
nam es and types: a com parison betw een M esem bryanthe­
m aceae a n d Poaceae. Bothalia 15: 125-129,
B othalia 15. 3 & 4 (1985)
G iB B S R U S SE L L . G . E .. RE T1E F. E. & S M O O K . L .. 1984.
intcnsitv o f plant collecting in sou th ern A frica. Bothalia 15:
131-138.
G O L D B L A T T . P .. 1978. Analysis o f the flora o f sou th ern
A frica: its characteristics, relationships and origins. A im .
Mo. hot. (k in 65: 369-136.
G O L D B L A T T . P. & BON 'D. P .. 1984. Plants o f th e C ap e Flora
— a descriptive catalogue. Jl S. A fr. But. Suppl. 13.
G O O D , R .. 1974, The geography o f the flowering plants, edit 4.
London: Longm an.
H E P P E R . F. N'.. (e d .). 1963. Flora o f West Tropical Africa, edn
2. Vol. 2. L ondon: C row n Agents.
H E P P E R . F. N .. (e d .). 1968. Flora o f West Tropical Africa, edn
2. Vol. X I. L ondon: C row n A sents.
H E P P E R . F. N .. (e d .). 1972. Flora o f West TropicaI Africa, edn
2, Vol. .1,2. L ondon: C row n Agents.
JA C O T G U 1L L A R M O D . A ,, 197*1. Flora o f Lesotho. W einheim : C ram er.
629
K E A Y . R . W . J .. ( e d .). 1954. Flora o f West Tropical Africa, edn
2. Vol. 1,1. L ondon: C row n Atients.
K1LL1CK. D . J. B.. 1971. Progress7 w ith th e Flora o f Southern
A frica. Milt. hot. SiSamml.. Miinch. 10:76-79.
L EV Y N S . M. R .. 1964. M igrations and origin o f th e C ape Flora.
Trans. R. Soc. S. Afr. 37: 85-107.
M E R X M U L L E R . H .. (e d .). 1966-1970. Prodromus einer Flora
ron Siidwestafrika. W einheim : C ram er.
M E Y E R , F. G ., 1973. E num eration o f E thiopian sperm atophytes. Taxon 22: 655-657.
R O SS. j . H .. 1973. Flora o f N atal. Mein. hoi. Sure. S. Afr. 39.
W E IM A R C K . H .. 1941. Phytogeographiea! g roups, c en tres and
intervals within the C ape flora. Acta Univ. lund.. 37:5-143.
W ELLS. M.
E N G E L B R E C H T . V. M .. BA LS1N H A S. A. A.
& S T IR T O N . C . H ., 1983. W eed flora o f South A frica 2:
pow er shifts in the veld, Bothalia 14: 961-965.
W H IT E . F .. 1983. Vegetation m ap o f Africa. Paris: The U neseo
Press.