J . Linn. Soc. (Bot.)60, 383, p . 237
With 5 jlyures
Printed in arcat Britain
Pebnuc.ly, 1968
237
The taxonomy of Sulwia: a test of two radically different
numerical methods
BY A. EL-GAZZAR, L. WATSON, F.L.S.,
Botany Department, Southmptm University
w. T. WILLIAMS, F.L.S. AND a. N. LANCE
C.S.I.R.O. Computing Research Section, Canberra, Australia
(Acceptedfor publication September, 1967)
Forty-one variations in calyx morphology and venation, stamen form, trichomes, style
&ape and aspects of habit and gross vegetative morphology were recorded for a cosmopolitan
sample of 100 Salvia species. Comparative data were subjected to computation under two
fundamentally different programs, MLJLTCLAS (a mixed-data method) and CENTCLAS
(taxonomically crude, strictly qualitative). "he resulting classifications were essentially
similar, but not identical; and inspection suggests that the differences result largely from
taxonomic distortion inherent in the CENTCLAB method.
A classification of these Salviaa is suggested, taken from the MULTCLAS hierarchy, which is
fundamentally different from anything yet proposed by taxonomists. Of the five subgenera,
only Cabsphace has gained support; and of the twelve sections only Hymenosphace is homogeneous. The new scheme seems taxonomically reasonable, and is informative in that the
groupings are consistent with observations other than those on which it was based. The main
subdivision represents a distinction between Central and South American Salvias and the
rest, and reflects variation in stylar morphology, though neither geography nor stylar form
were subjected to computation. It is concluded that even CENTCLAB, used alone, could have
greatly enhanced the taxonomic understanding of this well-known genus.
INTRODUTOTION
Salvia is t)helargest genus of Labiutae and one o f the best known, taking in some of the
most spectacular species. Bentham (1832-6) was unhappy about the quality of his
specimens and confessed dissatisfaction with his classification; but, as in so many other
caws,his account represents the most recent attempt a t a world monograph, notwithstanding a threefold increase in the number of described species since his day. The treatment of Briquet (1897) is in essence a nomenclatural variant of Bentham's, and later
taxonomic accounts of Salvia are restricted to regional floras. The most important of
these is the work of Epling (1938, 1939), who has given descriptions for 600 species,
distributed among 91 sections. However, he has dealt only with American species, the
majority of which were grouped by Bentham under the subgenus Cahp?um. A morphological study of Salvia stamens by Zalewska (1928) has never been incorporated into the
taxonomy of the genus.
Clearly Salvia is due for a taxonomic reappraisal, and interested as we are in the application of numerical techniques to Angiosperm taxonomy, this genus appealed to us as a
suitable subject for investigation.
OBSERVATIONS
The accepted classification of Salvia reflects Bentham's obsession with stamens, and
there is precious little comparative information on record. However, these plants have
16
238
A. EL-GAZZAR,
L. WATSON,
W. T. W ~ ~ ~ z a ~aLaNsDG. N. LANCE
readily provided a splendid catalogue of variations. Most of the observations are novel;
but they are all of the kind that can be made rapidly without sophisticated techniques.
The calyx
M~PhOklY
The Salvia calyx conforms with the usual Labiate pattern in seeming to represent five
fused sepals. However, the calyces of our sample can be arranged under five headings as
follows:
(1) Calyx &dentate, with all the teeth more or less equal (Fig. 1a).
(2) Calyx bilobed, dorsal lobe entire, and two ventral teeth which may be very small
(Fig. 1b). That of S. leucophyUa Greene seems best regarded as a modification of this
type, in which the ventral teeth are absent.
(3) Calyx bilobed, with the dorsal lobe bicuspidate, and two ventral teeth. The
dorsal lobe may be notched in the middle (Fig. 1c), or not (Fig. Id).
(4) Similar to type (3), but having the dorsal lobe tricuspidate (Fig. le). In some
species (e.g. S. sylvatria L,),
the two lateral spines of the dorsal lobe overlap the middle
one (Fig. If).
( 5 ) Calyx generally much larger in size than in types (1)to (4), the teeth more or less
equal, obtuse and expanded (Fig. 1g).
Annulue
Some species manifest a dense ring of simple hairs within the calyx throat : we call this
the ‘annulus’, and have simply recorded its presence or absence.
Venation
The number of main veins in the calyx is remarkably constant within the species, but
among them varies from 8 to 17 or more. The vein number is not a mere reflection of calyx
shape: for example, our calyx type (2) may have 8,9,11,13,14 or 15 veins; and the same
vein numbers occur in different calyx types.
Cell-walls of inner epidermis
In 70 yoof the species examined, the cell-walk of the inner epidermis of the calyx tube
are heavily thickened with many oanal pits traversing them. There am some species where
the calyx does not show this condition a t all, and some where the thickened walls are
confined to the basal region.
Calcium oxalate crystals are found in the calyces of many species of Salvia. Their shapes
and sizes are so variable that we have contented ourselves with recording only their
presence or absence. They are consistently absent among certain African species.
The atamem
We have been unable to recognize all the stamen types delimited by Zalewska (1928),
who contemplated them from a ‘funotional and adaptive ’ standpoint. It seems to ua that
four basic types can be recognizedusing as oriteria the nature of the two ends of the articulated connective, as well as other morphological features:
239
Fig. 1. Calyx morphology of S a l k : (a) 8.luvanduhefolia; (b) S. apecioaa; (c) S.piaidica;
(d)S.roemeriama; (e)S.roaaefolia; (f)8.aylvealria; (8)S.acetabu2oaa. Venation is omittedonly
in (g). For descriptions aee text. (a) to (f), x 6; (g), x 2.6.
240
A. EL-GAZZAR,
L. WATSON,
W. T. WILWS AND G. N. LANCE
(1) The two parts of the connective unequal, the longer being fertile while the
shorter is sterile and reduced to a small process receiving no vascular supply from the
staminal filament (Fig. 2 a).
(2) Similar to the preceding, but the sterile part of the connective is much longer and
furnished with a vascular strand from the staminal filament. The sterile parts of the
two stamens in the flower are often in contact via the minute glandular hairs on the
adjacent margins (Fig. 2b).
(3) Both arms of the connective Worm, more or less equal, and fertile, but the two
main pollen-producing cells of the stamen are morphologically distinct (Fig. 2 c). We
place the stamens of 8.curduacea and S. columbariae under this heading although they
lack the articulation between the staminal filaments and the connectives.
(4) Only the outer end of the connective is fertile while the inner is typically sterile,
short, broad and flattened. The flat parts of the two stamens in the flower are usually
contiguous via their abortive half-anthers (Fig. 2 d).
C
Fig. 2. Type8 of stamens in Salvia: (a)S. vel.ticillala; (b)S. ombrophila; (c) S. hegelmaitri:
(d)S. dominica. All x 6.
Numerical tuxorunny of Salvia
241
Forma of hairs
Leaves, bracts and calyces of Salvia species are commonly invested with hairs, of which
five types are easily distinguishable :
(1) Simple, multicellular and eglandular, with the apical cell shortest and pointed
(Fig. 3a).
(2) Similar to type ( l ) , but with the apical cell in the form of a globular secretory
gland (Fig. 3b) .
(3) Similar t o type (1),but with the apical cell in the form of a very long and narrow
appendage, its lumen occluded (Fig. 3c).
(4) Long, undulate and intermingled to form a dense compact mat covering the leaf
surface. The cell junctions are noticeably swollen (Fig. 3d).
( 5 ) Uniseriate branched (Fig. 3e), confined to certain species in Central and South
America.
Fig. 3. Diagrams of the hair types found on leaves, bracts and calyces of Sulvia species. See
text for details. x 13.
All these types occur on leaves, bracts and calyces, although the combinations vary
from species to species. Furthermore, in any species the indumentum of leaves, bracts
and calyces may be different.
242
A.EL-GAZZAR,
L. WATSON,
W. T. Wmmius AND G.N. LAXW
The style
The fldvvia;style is always unequally bXd and borne underneath the upper lip of the
corolla. In some speciesthe upper arm of the style is much longer than the lower (Fig. 4a);
elsewhere the opposite is the case (Fig. 4b). The style is more or less hairy in some species,
glabrous in others.
Fig. 4. (a) Style of S. anguelqoZolia with the upper arm longer than the lower, (b) that of
S.fiinnata with the lower arm longer than the upper. x 13.
Vegetative w p b b g y
We have made use of a few gross morphological characters, easily recorded fiom herbarium material but seemingly ignored by taxonomists. Leaves may be aimple or dissected;
narrowly linear and sessile or broad and petiolate; smooth or rugose; glabrous or densely
hairy. Bracts may be reflexed or surrounding a glomerule of flowers.
Table 1. &mmay of compra.tive observathns recorded for 100 Salvia
spec;@. Characters 1 to 15 were subje.cted to m ~ hchamctere
;
16 and 17 were left out
Qualitative charactera :
h8VeS :
1. Simple/compound
2.
eeseile/petiolate
3. smooth/rugoee
4.
calp-oq&&, present/absent
calyx :
6. cell-wallsof inner epidermis, thickened/not thickened
annulusof haim within calyx-throat, present/abbsent
6.
7.
reflexed/not reflexed
Bracts:
Stamens:
8.
staminel filaments or connectives, hairy/glaborus
9.
hairy/glaborue
Style :
Multistate charactera:
Calyx :
10.
number of main veins, 9 categories
type of calyx, 6 categorim
11.
12.
type of stamen, 4 categories
Stamens:
Hairs :
13.
tyPeS Of h 8 h On CdJ’X, 4 C a h g O r i e S
types of hairs on leaves, 4 categoriee
14.
types of haim on bracts, 4 cat0gories
15.
Additional characters :
Stamens:
16.
inner end of connective, pointing upwarda/pointbg
d o w n d
Style:
17.
upper arm longer/lower arm longer
Numerical taxonomy of Salvia
243
We have examined a cosmopolitansample of 100 species including representatives from
the questionable genera Audibertia Benth. and Salviastrum Scheele; also Schraderiu
Medic., which is Bentham’s section Hymemsphace promoted to generic rank. The sample
thus takes in about 10 yoof Sdvia semu 2ato. Table 1 summarizes the characters recorded,
which were classified as ‘ qualitatives’ and ‘multistates’ for a mixed-data analysis (see
Lance & Williams, 1967). Characters 13 to 15 are multistates of the non-exclusive type,
where there is more than one possibility for a single species (i.e. one plant may exhibit
more than one of the hair types on any of the organs studied). I n certain species having
caducousbracts we were unable to record characters 7and 15, which were thus inapplicable
in five cases. Characters 16 and 17 were recorded, but were not incorporated in the
numerical analyses: they were kept in reserve, along with geographical and cytological
information, for use in evaluating the results.
THE PROGRAMS
The data were analysed as follows:
(1) Under the mixed-data program MULTCLAS, which uses the non-metric coefficient
and has provision for ‘flexible’ sorting, in which ‘reversals’ are impossible and the intensity of clustering can be varied by changing the parameter /3. Experience suggests that
a suitable value of Pfor most purposes is - 0.25, and this was used here. MULTCLAS caters
for qualitatives, inapplicables and multistate characters including non-exclusives, and
also for quantitative characters, which were absent from our data. For details of the
program, see Lance & Williams (1967); MULTCLAS is the program therein referred to as a
version of MULTIST using flexible strategy.
(2) Under the program CENTCLAS. This is the program referred to in Lance & Williams
(1967) as CENTBET; it caters for qualitative or continuous data, but not for multistate
attributes or mixed data, and uses a conventional ‘centroid’ sorting strategy. It has a t
present no provision for missing or inapplicable values. We have used it in its qualitative
form with an information statistic, which involved dichotomizing all the information,
including that for the multistate attributes. The theory of the statistic used is given in
Lance & Williams (1966).
COMPARING THE RESULTS O F TEE TWO ANALYSES
The total information content, as given on the computer print-out, has been used as a
measure of level when plotting the CENTCLAS hierarchy (Fig. 5). For the MULTCLAS
Table 2. Comparison between the alternative groups of Salvia species under MULTCL~Sand
CENTCLAS schemes in t e r n of the species they contain. Asterieb indicate w
e
s of migration
BfULTCLAS
Group 1
8. verticillata, S. bwnmuelleri, S. sprucei*,
macroetaohya*, S. clevelandi, S. apiana,
aonomenaia, S. leucophylla, S. nzellijera,
spathacea, S . craaaijololia. S. acetabubaa,
cryptantha, S. ajricana, S. aurea, S . nivea,
cana&nsia, S. cmpresaa.
OENTOLAS
S.
S.
S.
S.
S.
S. verticillata, S . bwnmuelleri, S . clevelandi,
S . apiana, S . aonomenaia, S . mellijera, S .
argenteo*, S . crassifolia, S. acetabuloea, S.
dracocephaloides, S. cryptantha, S . ajricanu, S.
aurea, S. nivea, S. canarieneis, S. cmpreaea.
Group 2
S. verbenaca, S . patensis, S. horminum, S .
hnata, S . montbretii, S. viridia, S. virgata, S.
glutinoaa, S. argentea, S. sylvestria. S. aclarea,
S. pandiflwa*, S. hieroaolymitana,S. bicolor, S.
aethiopia.
S. verbenaca, S. prdenaia, S. horminum, S.
lanata, S. montbvetii, S . viridis, S. virgah, S.
glutirwaa, S . sclarea, S. hkT080&?&3TW, S.
bicolor,S. aethiopia, S. bahnaae*, S.jaminiana*.
A. EL-GAZZAR,
L. WATSON,W. T. wIlm4.M~AND G. N. IANCIE
244
Table 2--continued.
Group 3
s.plxdim, libanotim, s.triloba, o$kinalia,
S. lavandulaefolia,S. aromdica, S. aucheli, S.
hqelmaieli, S. candelabrum.
s.
s.
Group 4
S. m d m c e a , S. columbariae, S. texana, S.
plebeia, S. dltiorhiza, S. japonica, S.forakohlei,
S. hlleyana, S. lyrata, S. pinnata. S. campanulata, S. roemeriana, S. roaaefolia*, S. heterotricha+, S. irablitziana, S. dracocephaaloidea*.
Group 6
S. runcinata, S. monticola, S. cooperi, S.
dominim, S. balanaae, S. controveraa, S.
jaminiana, S. atenophylla, S. deaerti. S.
aegyptiaca.
Group 6
S. aplendene, S. lavandubidea, S. coocinea, S.
g r a h i , S. lasiocephala, S. srcbinciaa. S.
hyptoidtw, S. corrugates, S. pocurrena, S. lachnoata;ehya, S. remota, S. meximna, S. azurea, S.
npecioaa, S. benthamiana. S. farinucm, S.
fulgena, S. lanceolata, S. roamarindda, 8.
tortuoaa, S. pranenaw, S. ornbrophila, S.
conferti)%ra, S. meliaaaeflora, S. involucrda.
S. piaidiea, S. libanotiea, S. tribba.S. o&inalia,
S. grandiflora, S. aromatica, S. l y r d a f , S.
lavandulmfolia. S. aucheri, S. hegelmaieri, S.
candelabrum.
S. carduacea, S. coludariae, S. tezana, S.
plebeia, S. miltiorhiza, S.japonica, S. forakohlei,
S. bulleyana, S. pinnakz. S. eanyxmulokr, S.
roemeriano, S. habliteiana, S. roeaefolia+, S.
aylveatria+,S. atenophylla+.
S. runcinata, S. monticob, S. cooperi, S.
dominica,S. controveraa,S. deaerti, S. aegyptiaca.
S. applendena. S. lavandubidea, S. coccinea, S.
grahwni, S. lasiocephala, S. aubinciaa, S.
hyptoidea, S. c m g a t a , S. procurrena, S. lachnoatachya, S. r e w t a , S. mexicana, S. azurea, S.
apowaa, S. benthamiana, S. f a r i m , S.
fulgena, S. lanceolalcr, S. roanw7inoidea, S.
tortuoaa, S. a p w e i , S. mucroatachya, S.
paranen&, S. ombophila, S. confertiflora, S.
m l k a w f l o r a , S. involucrata, S. M e r o t r i c h , S.
anguatifolia, S. paewlo-coccinea. S. acoparia, S.
apathaoea+.
Group 7
S. anguatifolia, S. paeudo-coccinea, 9. revoluta,
S. acoparia, S. leucocephala, S. flooculoeo, S.
wriiana.
S. leucocephala. S. revoluta, S. moriana, S.
flocculoaa, S. leucophylla*.
Table 3. Diugm8tic features for group8 C and D in Fa& 5 , picked out by
eye from the data-matrices as rearranged under MULTCUS and CENTOLAS
respectively
CENTCLAB
1.
2.
3.
4.
5.
6.
7.
8.
Group C (37 species)
Leaves dissected in 10 species.
6 species with type (1)stamens.
25 species with type (4) stamens.
6 species with type (3) stamens.
3 species with ‘annulus’ of
hairs within calyx-throat.
9 species with type (6) calyx.
No species with type (1) calyx.
34 species with 13-veinedcalyx.
Group D (26 species)
1. Leaves dissected in 12 species.
2. No species with type (1) stamens.
3. One species with type (4) stamens.
4. 26 species with type (3) stamens.
6. 4 species with ‘annulus’ of
hairs within calyx-throat.
6. No species with type (6) calyx.
7. 8 species with type (1) calyx.
8. 6 species with 13-veinedcalyx.
MULTCLAB
Group C (42 species)
1. Leaves diseected in 4 species.
2. 8 species with type (1) stamens.
3. 20 species with type (4) stamens.
4. 12 species with type (3) stamens.
6. No species with 'annulus' of
hairs within calyx-throat.
6. 8 species with type (6) calyx.
7. 8 species with type (1)calyx.
8. 29 species with 13-veinedcalyx.
1.
2.
3.
4.
6.
6.
7.
8.
Group D (26 species)
Leaves dissected in 18 species.
No species with type (1) stamens.
6 species with type (4) stamens.
19 species with type (3) stamens.
7 species with ‘annulus’ of
hairs within cdyx-throat.
One species with type (6) calyx.
No species with type (1) calyx.
13 species with 13-veinedcalyx.
Numerical tuxonmy of Salvia
L
25
246
I
MULTCLAS
CENTCLAS
1600
22
1400
20
A
1200
1.7
1000
1.51
C
D
C
800
12
600
I O(
0.7i
II
7
I:
lhbbl
10
25
7
6 1
400
I
Fig. 6. The MULTCLAS and CENTCLAS hierarchies for 100 Sulwia. species (seeTable 2), baaed on
the characters listed in Table 1. Numbers of species in the low-level groupingsare indicated.
hierarchy, where no exactly comparable measure exists, the non-metric measure a t the
point of fusion has been used to define the level. For purposes of discussion, we had t o
choose stopping levels beneath which further subdivision of groups seems taxonomically
unprofitable. This does not mean that we consider the very low-level aggregations meaningless : merely that the similarities between adjacent groups are so high that we have been
unable to discover external criteria to support them.
The two hierarchies coincide closely regarding the two main groups of Salvia species, A
and B in Fig. 5 . They also agree t o a marked extent over the low-level groupings 1 to 7 : in
fact the small group 7 is the only one showinga correspondence ofless than 70 yoamong the
species (Table 2), and the only major difference between the two hierarchies concern the
relative positions of the two groups 3 and 5 in C and D. In order to evaluate taxonomically the divergent versions of C and D, i t is necessary to reconsider the data-matrix as
rearranged by CENTCLAS and MULTCILASrespectively. Table 3 summarizes the correlating
characters which pick out the groups: for the sake of simplicity we have left out those
characters where there are no obvious correlations in this context. Taking the CENTCILAS
arrangement first, we we that there is no criterion here for a n absolute distinction, but the
two groups exhibit markedly different tendencies regarding stamen types (2,3 and 4), and
246
A. EL-GAZZAR,
L. WATSON,
W. T. W
m AND G. N. LANCE
calyx form and venation (6,7 and 8). The most impressive correlationhere is between type
(4) stamensand 13-veinedcalyces, involving 23 out of 37 species in group C. The MULTCLAS
arrangement also picks out two serieswith different tendenciesamong calycesand stamens,
but the distinctions regarding features 3,4,6 and 8 are less clear. On the other hand it can
be seen that MULTCLAS is also acknowledging distinctions (not absolute, but impressive)
in leaf form (1) and calyx construction (6) ignored under CENTCLAS. Furthermore, the
MULTCLAS treatment has placed in group C 16 out of the 17 Salvias in our sample with
calyx types (I) and ( 6 ) ,and in doing so it draws attention to a fact which we had overlooked while investigating calyx morphology. There are only 17 species in which the
calyx is not markedly 2-lipped, and of these eight constitute our calyx type (I), the rest
type (6). We take it as morphologically significant that 16 of them are aggregated in
MULTCLhS group c!
We consider the MULTCLAS version superior, since it accounts for more aspects of the
plants’ diversity, and has even taught us something about calyx morphology.
REALLOOATION
It is in theory possible to re-examine the constitution of the groups at any chosen level
in the hierarchy, to ascertain whether any of the individuals would be more appropriately
placed in a different group, thus redressing errom due to the ‘migration problem’. The
method is necessarily iterative, but, at least in a strictly Euclidean system, the process is
known to converge rapidly (for an account, me Jancey, 1966 ; for a proof of convergence,
see Needham, 1966). The problem of its extension to non-Euclidean classificatory models
(such as we have used) is under investigation, but has so far proved intractable. As a
compromise solution, we have reallocated the 8dvia species on a Euclidean model with
the attribute-axes weighted according to their contributions to the primary classification.
The operation was carried out on the MULTULAS hierarchy, at the 7 groups level: i.e. across
the minor groupings 1 to 7 in Fig. 5 . It resulted in six reallocations, which we judge to be
very reasonable. It is noticeable that five of the reallocated species were correctly placed
under UENTGZAS(cf. Tables 2 and 4). Table 4, in our view, represents a satisfactory arrangement of Sdvia speciesin the light of the available evidence, with the six transfers indicated
by asterisks.
Table 4. Chai$cation of Salvia 8pecim. Derived f r m the MULTOLAS hierarchy (Fig. 5),
but incorporating reallocations (aaterisked; 8ee text)
Group A
Group 1
S . uerticilhfa L., S. bornmwlkri Haueskn., S. ckve&ndi Greene, S . spalhacea: Greene, S. aphna
Jepson, 8.kwrophylh Greene, 8.met,?ift?m areene, 8. 8munnek Greene, 8.acetabubm L.,
S. dracocephuEoides* Boias., S. cryptontha Montbr. et Auch., S. afrioana L., S . aurea L.,S. n k
Thunb., S. ConariSnaia L., S. compema Vent, S. m a a f o l h Ded.
Group 2
S. eylveetria L.,S. viddia L., S. montbretii Benth., S. hnutu Roxb.,S. sclarea L.,S. aethiopia L.,
S. verbena00 L.,S . prate& L.,S. lwrminm L.,S. argent- L..S. glutinoea L., S. hieroeolynilomc
Boim., S. virgata Ait., S . bicolor Lam.
Group 3
S. pieidieo B o k . et Heldr., S. libanotica Bobs. et Gaill., S. ofiinalia L., S . grandiflora* Etling,
S. tsilobo L., S. aromdiCa Boh., S. auoheri Benth., S. ?bqelmaieri P. & R., S . candelabrum Boiss.,
S. &vandukwfoZbVahl, S. ro8aefolia* Sm.
Group 4
8.wtvhacea Benth., S. co2wmbariue Benth., S. tezona Gray, S. miltiorhim Bunge, S. japonico
Thunb., 5.forskohki L.,S. plekia R. Br., S. bzrlleyana Diels, 8.c a m p a n u b Wall., S . hablitzkana
Pall.,S. roemel.iana Scheele, S. pinnda L.,L7. lgmta L.
Numerical t m m y of Salvia
247
Group 5
S. runcinata L., S. wwn&kola Benth., S. cooperi Skm., S. balansae No6, S. dominim L.,S. atenophylla Burch., S. controversa Tenore, S . jaminiana Nod. S. deserti Decne., S. aegyptiaca L.
Group B
Group 6
S. splendens Sello., S. lavanduloidee H. B. & K., S. coccinea Juts., S. grahami Benth., S. mbincisa
Benth., S. lasiocephab Hook. et Am., S. h y p t o d a Mart. et Gal., S. comugda Vahl, S. lachnosiachys Benth., S. procurrene Benth., S. remota Benth., S. wxicanu L., S. azurea Lam., S.
paranensis Dudn, S. speciosa Presl. S.fahnacea Benth., S. benthamiana Gardn. et Field., S.
fulgens Cav., S. lanceolata Willd., S. tortuosa H. B. & K., S. rom7inoidee St. Hil., S. conferti&n-a
Pohl, S. lnelieaaeJlwaBenth.. S. ombrophila DusBn, S. involucrata Cav.. S. heterotricha* Fernald.
Group 7
S. angustijolia Cav., S. pseudococcinea Jacq., S . acoparia Epling, S. macroatachya' H. B.& K.,
S. ~ p r u c e i * Briq.. S. revolt& Ruiz et Pav., S. leucocephala, H. B. & K., S. jeocculoea Benth.,
S. mariana Mart.
Table 5. Comparison between the orthodox c2assiJicationsof Salvia (includingAudibertia,
Salviastrum and Schraderia) and groups 1 to 7 of Table 4. Name-s are t h e of Bentham
(1832-6, 1848), Bentham S Hooker (1876) and Briquet (1897) for mbgenera and (in
parentheses) sectiom. Numerals indicate numbers of species
Group 1
(17 species): S a l k (Euaphace), 2 ; Salt& (Hywnoephace; Schraderia), 6 ; S c h e a (Aethiopie),
1; Leonia (Hemisphace), 1 ;Audibertia, 6.
Group 2
(14 species): Salwia (Drymosphace), 1; Sclara (Hormunum), 2; Sclarea (Aethwpia), 6; Sclccrea
(Pleithioephace),5.
Group 3
( 11 species): Salwia (Euaphace), 11.
Group 4
(13 species): Salvia (Eusphace), 1; S a l k (Drymoephace), 4; Leonia (Pycnoqhace), 1; Leonia
(Echinoephace), 1;Leonia (Notwuphace). 2; Leonia (Heteroephace),2; Salvia9trum, 1.
Group 6
(10 species): Sclarea (Pleithioephuce), 3 ; Leonia (Heteroephace), 2; Leonia (Notiouphuce), 2.
Group 8
(26 specks): Calosphace (Caloephme), 26.
Group 7
(9 species): Caloaphace (Caloephace), 7.
Table 6. Diagnostic features of group8 A and B in Table 4 . Features 1 to 7 were picked out
by eye from the rearranged data-matrix; features 8 to 10 are additional, i.e. not subjected to
computation
Group A (85 species)
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
All types of calyx.
Stamen types ( l ) ,(3) and (4).
Stamens glabrous in 60 pciee.
Style glabrous in 59 species.
Leaves dissected in 22 species.
36 species with glandular hairs.
No branched ha& on calyx, bracts, or
leaves except in S. lewophylla.
Lower lobe of style longer than upper.
Inner end of connective points upwards
in 61 species.
European, Asian, Afrioan and North
American species.
Group B (36 species)
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Calyces of type (2) only.
Stamen type (2) only.
Stamens hairy except in S. lanceolata.
Style densely hairy in 28 species.
Leaves always simple.
27 species without glandular hairs.
11 s p i e s with branched heirs on all or
any of calyx, b r a t s or leaves.
Lower lobe of style shorter than upper.
Inner end of connective points
downwards.
Only Central and South American
species.
248
A. EL-GAZZAR,
L. WATSON,
W. T. WILLT~MS
AND G. N. LANCE
Table 7. Dkqm8tic featurm of groups C and D in Table 4. Features 1 to 6 were picked out by
eye from the rearranged data-matrix;features 7 and 8 are additional
Group A , C (42 species)
1. Leaves simple in 36 species.
2. Stamen types (1) (8 species), (3) (14
species) and (4) (20 species).
3. No species with ‘annulus’ of hairs within
calyx-throat
4. Calyx types ( 1 ) and (5) account for 17
species (i.e. calyx often more or leas
regular).
5. 41 species with crystals in calyx.
6. Leaves sessile in only 3 species.
7. No species with flowers less than 1 cm long.
8. Species mainly European and
Mediterranean.
.
Group A , D (23 species)
1. Leaves dissected in 16 species.
2. Stamen types (3) (17 species) and (4)
(6 species).
3. All species with the ‘annulus’ ( 7 ) fall
in this group.
4. Calyx types ( 1 ) and (6) absent: calyx
always 2-lipped.
6. 8 species without crystals in calyx.
6. Leaves sessile in 12 species.
7. 7 species with flowers leas than 1 cm long.
8. North and South African, East Asian
and North American species.
TAXONOWO DISCUSSION
Our treatment of Salvia species bears little resemblance to any orthodox classification.
Comparison of Table 4 with Table 5 shows that of the five subgenera only Cahphuce
emerges intact and of the 12 sections only Hymenosphace appears to be homogeneous.
The species from Audibertia, Salvbtrum and Schraderiu have all been submerged among
the Salvias.
We intend to carry out further computations in order to investigate the feasibility of
extracting diagnoses by these means. In the meantime, Tables 6 and 7 serve to show that
our scheme not only accounts for the wide range of comparative observations listed in
Table 1, but that it is also in harmony with evidencethat was not subjected to computation.
Thus, the recognition of two main groups of Salvia species ( A and B) is supported by the
additional criterion that it represents an absolute distinction between speciesof our sample
with the lower arm of the style longer than the upper (groupA), and those (groupB) where
the opposite is the case. Geographical distributions of the species are also illuminating;
for group B is Central and South American whereas group A takes in species from the
rest of the world. A variation in stamen form, observed by Bentham (1832-6) but not
satisfactorily accounted for in his taxonomic scheme, is also in harmony : in group B the
inner end of the articulated connective is sterile and points downwards, while in group A
it is sometimes fertile and usually pointing upwards.
Table 7 shows that groups C and D are a h geographically credible. Group C is
mainly European andMediterranean, although a few speciesoccur in Persia, the Himalayas
and South Africa ; group D, on the other hand, takes in the majority of North American
and East Asian Salvias (a discontinuity well known to phytogeographers)as well as some
exclusively North and South African species. Furthermore, even in our fragmentary
specimens, the suggested redistribution of the species imposes some pattern on variation
in flower length; for 20 out of 26 species in group A with flowers more than 2 cm long fall in
group C, while all seven species with flowers less than 1cm long are in group D .
Any nomenclatural confusion arising out of problems of species delimitation could make
nonsense of minor groupings in the lower reaches of a hierarchy. However, from a
geneticist’s point of view, the low-level fusions (indicating, we hope, possibilities of
hybridization) are of interest. Thus although the restricted size of our ample limits the
direct value in floristicwork ofthe minor groupings 1 to 7 in Fig. 5, it is worth attempting to
assess their taxonomic worth. As might be expected, it is not eaay to discover additional
features to distinguish adjacent low-level groupings. In fact, we have not as yet found any
criteria to support the splitting of the Central and South American Salvias (i.e. group B)
into groups 6 and 7 other than the hair differences involving leaves, calyces and bracte
Numerical twonumy of Salvia
249
which were picked out by the computer. However, the minor groups 1 t o 5 certainly seem
taxonomically reasonable (see Table 8). In the first place they are geographically likely,
with ten African species constituting group 5, group 2 centred on the Mediterranean and
groups 1 and 4 exhibiting the well-known phytogeographical discontinuity between
East Asia and North America. The flowers ofSalviaspecies are generally 1.5 to 3-0cm long,
and in our entire sample only ten species had them less than 1.0 cm. It is, therefore,
Table 8. Diagnosesfor the seven low-level groups of Salvia species shown in Table 4. Features
in bold were not incorporated in the computation. Cytological data from Stewart (1939),
Darlington & Wylie (1955), and Cave (1958-64). Figures in parentheses indicate numbers
of species in each group for which chromosome counts are on record
Group
Diagnostic characters
1 Calyx 13-veined,types (2)and (6). Bracts and calyces without hair types (2) and (4). Cell-walls
of inner epidermisof sepals not undulateand thickened (a rare situation)in 10/17 species. Leaves
simple in 16/17 species. Stamen types (1) and (4). filaments glabrous. Style glabrous in 16/17
species, lower lobe longer than upper. Inner end of connective pointing upwards.
Chromosome numbers (8)multiples of 8,11,12 and 13. Californian and Asian species.
2 Calyx 13-veined,type (4).Bracts and calyces with hair types (2)and (4).Leavessimple. Stamens
type (a), filaments glabrous. Style glabrous in 12/14 species, lower lobe longer than upper.
Inner end of connective pointing downwards. Chromosome numbers (8) multiples of
8 and 11. Mediterranean and S . European species.
3 Calyx 14- or 17-veined,mainly type (1). Stamens type (3), filaments glabrous. Style glabrous,
lower lobe longer than upper. Inner end of connective pointingupwards. Chromosome
numbers (2) multiples of 7. Mainly European species.
4 Calyx 11-veinedexcept in S. carduecea and S. columbarke, mainly type (2); ‘annulus’of hairs
within the throat in 4 species. Leaves dissected in 7/13 species.Stamenstype (3).filamentshairy
or glabrous. Style often glabrous, lower lobe longer than upper. Inner end of connective
pointing upwards. Chromosome numbers (4) multiples of 8, 9, 12 and 13. Chinese,
Japanese and N. American species.
6 Calyx 13-veinedexcept in S. monticoh and S . cooperi, type (4).Bracts and calyces without hair
types (2) and (4). Leaves dissected and sessile. Calyx-crystalsin only 3 species. Stamen types
(3) and (4), filaments glabrous. Style glabrous, lower lobe longer than upper. Inner end of
connective pointing upwards. Flowers small, sometimes minute (less than 1.0 cm in
5/10 species). Chromosome numbers (2) multiples of 8. N. and S. African species.
6 Calyx 8-, 9-, 11-, 13-, 16-or many-veined,of type (2)except in 5. procurrens. Leaves and braata
without hair type (6). Leaves simple. Stamens type (2), filaments often hairy. Style commonly
hairy, upper lobe longer than lower. Inner end of connective pointing downwards.
Chromosome numbers (3) multiples of 11. Central and South American species.
7 Calyx 13- or 14-veined,type (2). Bracts, calyces and leaves with hair type (6). Leaves simple.
Stamens type (2). filaments hairy. Style hairy, upper lobe longer than lower. Inner end of
connective pointing downwards.No chromosome counts on record. Central and South
American species.
interesting to find a n aggregation of five species with minute flowers among the ten species
of group 5 . We have seen that tho orientation of the inner end of the connective distinguishes, though not absolutely, between groups A and B. We now find that all the
species in Group A exceptional in this respect go to form group 2. Finally, although
chromosome counts are only sporadically available, i t is noticeable that both the cytologically known species in group 3 have multiples of seven-a number unknown elsewhere.
METHODOLOOICAL CONCLUSIONS
Watson, Williams & Lance (1966) have noted that taxonomic groups seem quite robust
in the face of variations in the numerical approach; and the present study supports this
250
A. EL-GAZZAB,
L. WATSON,
W. T. W
s-
AND
G. N. LANCE
suggestion.However,their data-matrix provided a less stringent test than our information
on Salvia, which, being more extensive, constituted a far more difficult problem. Furthermore, the methods compared by Watson, Williams & Lance were all of the same basic
type, confined to qualitative attributes with no provision for multistates and inapplicables.
Here however, we have used a qualitative method alongside a mixed-data method where
multistates and inapplicablesare catered for.
The differences between the two programs can be illustrated in terms of the characters
used here, by considering the characters 10 (calyx vein numbers) and 15 (bract hairs). A
species might exhibit any one of the nine venation types, but the presence of one logically
excludes the possibility of h d i n g any other. Under CENTCLAS, a species with 15-veined
calyx comes to differ from one with a 13-veinedcalyx by two characters; a state of affairs
unreasonable in giving undue weight to one aspect of calyx morphology. MULTCU
eliminates this sort of error, regarding the distinction as a single character difference. As
regards character 15, we were unable to record bract details (in fact five variants) in five
species.Under IWLTOWB these features simply become inapplicables,but for CENTCLAS we
were obliged to treat them as negatives. The species concerned, however, have appeared
in the same groups under the two sohemes.
In view of the fundamental differences between the two programs, the similarity
between the alternative hierarohies (Fig. 5 ) is remarkable. Had the level of taxonomic
understanding of Sdvia been high, the differences would have been important. But the
available classificationsof thia relatively well-knowngenus are 80 primitive that CENTCLILS
alone, using our quite short list of oharacters and with its illogical treatment of bract
details, could have made a valuable aontribution.
ACKNOWLEDQEMENTS
We wish to thank the Keepers of the herbaria at Manohester Museum, Edinburgh
University and the Botany School,Cambridgefor the loan of specimens.A. E-G. thanks the
Egyptian Government for financial support.
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