Synopsis of the genus Vitex (Lamiaceae) in the Democratic Republic of the Congo
Author
Meerts, Pierre
text
Plant Ecology and Evolution
2018
2018-11-28
151
3
380
392
http://dx.doi.org/10.5091/plecevo.2018.1504
journal article
10.5091/plecevo.2018.1504
7664390
11b.
Vitex madiensis
subsp.
milanjiensis
(Britten) F.White
(
White 1962: 455
);
Verdcourt (1992: 61)
;
Lebrun & Stork (1997: 524)
;
Sales (2001: 197
;
2005: 84
);
Coates Palgrave & Coates Palgrave (2005: 983)
;
Meerts & Hasson (2016: 336)
;
Meerts (2016: 231)
.
–
Vitex madiensis
var.
milanjiensis
(Britten) W.Piep.
(
Pieper 1928: 63
)
;
De Wildeman (1929a: 12
;
1929b: 105
);
Delevoy (1929: 483)
.
–
Vitex milanjiensis
Britten
(
Britten 1894: 36
)
;
Baker (1900: 330)
.
–
Types
: Malawi, Milanji [Mulanje], 6000 ft [
1800 m
],
Oct. 1891
,
Whyte
138 (syn-: BM barcode BM001124551);
Malawi, Zomba,
Sept. 1891
,
Whyte
s.n. (syn-:
BM
barcode BM000566972; Kbarcode K000249031
).
Vitex grisea
Baker
(
Baker 1900: 325
)
.
–
Type
:
Angola
,
Distr. Huilla
, in silvestribus alte dumetosis de Catumba,
Welwitsch
5759 (lecto-:
Kbarcode K
001067050,
designated here
;
isolecto-:
BM
barcode
BM
000839718),
synon. nov
.
Vitex huillensis
Hiern
(
Hiern 1900: 837
);
De Wildeman (1914b: 191)
nom. illeg.
Vitex hockii
De Wild.
(
De Wildeman 1914b: 113
;
1914c: 403
;
1921: 164
);
Pieper (1928: 61)
;
Delevoy (1929: 483)
.
–
Type
:
D.R. Congo
,
Haut-Katanga
,
Manika
,
Oct. 1911
,
Hock
s.n. (holo-:
BR
barcode
BR
0000008906557)
.
Vitex ringoetii
De Wild.
(
De Wildeman 1914a: 143
;
1914c: 407
;
1921: 165
).
–
Type
:
D.R. Congo
,
Nieuwdorp
,
Oct. 1912
,
Ringoet
1 (holo-:
BR
barcode
BR
0000005571505)
.
Vitex epidictyodes
Mildbr. ex W.Piep.
(
Pieper 1928: 61
;
1929: 164
)
.
–
Vitex madiensis
subsp.
milanjiensis
var.
epidictyodes
(W.Piep.) Verdc.
(
Verdcourt 1992: 61
)
;
Lebrun & Stork (1997: 525)
.
– Type:
Malawi
,
Langenburg
, am nordende des
Nyassa
,
Stolz
556 (First-step
lectotype
designated by Pieper (1929); second-step lectotype: Bbarcode B 100279988,
designated here
;
isolecto-: BM barcode BM001125198, Gbarcode G00366697, Pbarcode P00713461, Ubarcode U0040942, Zbarcode Z-000067396)
.
Differs from the
type
subspecies by the following traits. A shrub. Twigs stout, often wine red. Leaves 5 foliolate; lamina abruptly contracted at tip and cuspidate, very coriaceous, entire; upper surface very scabrid, reticulum prominulent.
Distribution
– Zambezian region, from Angola eastwards to Tanzania and Mozambique.
Notes
– Dwarf, geofrutescent forms of
V. madiensis
subsp.
milanjiensis
occur throughout the distribution range of
subsp.
milanjiensis
. They have been repeatedly described as
V. hockii
De Wild.
,
V. ringoetii
De Wild.
,
V. epidictyodes
W.Piep.
,
V. caespitosa
Exell. Such
forms pose two different taxonomic problems. First, it is unclear if they are genetically fixed or if, alternatively, they represent pyrophytic forms induced by burning;
Verdcourt (1992)
favoured the former hypothesis. Secondly, assuming it is genetically fixed, it is not clear if that morph is monophyletic or, alternatively, if it has evolved several times independently in response to selection by fire or other environmental constraints. Ihave not been able to find differences between dwarf and tall morphs except size.
Lectotypification of
Vitex epidictyodes
Mildbr. ex W.Piep.
Three
syntypes
are cited in the protologue (
Stolz
556;
Stolz
1478;
Trotha
95).
Pieper (1929)
designated
Stolz
556 as the
lectotype
(see
Verdcourt 1992
). Many specimens of that gathering have been distributed and
Pieper (1929)
did not indicate a specific herbarium; therefore second-step lectotypification is necessary (art 9.17 of ICN;
McNeill et al. 2012
). Since Pieper worked in Berlin, Itherefore select the specimen kept in Berlin as the
lectotype
.
Lectotypification of
Vitex grisea
Baker.
The specimen of
Welwitsch
5759 deposited in Kis chosen as the
lectotype
for two reasons. First it shows better the acute leaflet tips mentioned in the protologue; secondly, Baker worked at Kew Botanic Gardens after Welwitsch’s collections were split and, therefore, almost certainly used the duplicates deposited in K. This morphotype is a somewhat extreme variant in the phenetic variation space of the polymorphic
Vitex madiensis
subsp.
milanjiensis
not deserving formal taxonomic recognition.