Commelina mascarenica (Commelinaceae): an overlooked Malagasy species in Africa
Author
Faden, Robert B.
text
Adansonia
2008
3
30
1
47
55
journal article
10.5281/zenodo.5190388
1639-4798
5190388
COMMELINA MASCARENICA
IN AFRICA
The plant that would prove to be
C. mascarenica
was first recognized in Africa as a distinct species in
Kenya
(
Faden 1974
). Because no name could be found for it, the species was designated as “
Commelina
sp. D
”. No name had yet been discovered 20 years later, so the same designation was used in
Faden (1994)
. This species was recognized from
Somalia
in
Faden (1995)
, where it was called “
Commelina
sp.
#5”.
The identification of
Commelina
sp. D
and
Commelina
sp.
#5 as
C. mascarenica
happened as a result of a study that I began in 2000 of an apparently undescribed species of
Commelina
from coastal and subcoastal
Kenya
and
Tanzania
. That species (Faden in press) also has elongate, smooth seeds, so it became necessary to determine whether it might actually be
C. mascarenica
. I had not studied that species before, so in
March 2002
, in a loan from the Muséum national d’Histoire naturelle, Paris (P) to the Royal Botanic Gardens, Kew (K), I examined 14 of the 15 collections – all except
Perrier de la Bâthie 9018
, which was not sent – that were cited as
C. mascarenica
in
Flore de
Madagascar
(
Perrier de la Bâthie 1938
). Thirteen specimens appeared to belong to a species that significantly differed from my new East African species. The fourteenth specimen,
Bojer s.n.
, was a mixed collection, one part of which – designated by
Perrier de la Bâthie (1938)
as “
Bojer B
” – was indeed my new East African
Commelina
species
, and was not conspecific with the other 13 collections. The other part of the Bojer collection, “
Bojer A
”, belonged to an unrelated species,
C. lyallii
C.B.Clarke.
The 13 remaining collections from
Madagascar
and the
Comoro Islands
that were treated by
Perrier de la Bâthie (1936
,
1938
) as
C. mascarenica
were recognized as conspecific with my
Commelina
sp. D
and
Commelina
sp.
#5 because some of them, e.g.,
Decary 791
(P) from the
Comoro Islands
, had mature seeds that were identical to those of the African plants. However, because I now had evidence that my putative new species also occurred in
Madagascar
, it became necessary to examine the
type
of
C. mascarenica
, in order to determine to which species the name should be applied.
In
August 2002
, I was able to study the
type
of
C. mascarenica
, sent on loan to Kew from G. Although the
type
specimen was rather scrappy,and the capsule and seeds in the packet were immature, I had no doubt that this was same species as the 13 collections examined from P that were cited as
C. mascarenica
in
Flore de
Madagascar
and also matched African
Commelina
sp. D
and
Commelina
sp.
#5. Therefore the African plants were
C. mascarenica
too.
The first reference to
C. mascarenica
in Africa was by
Faden (2006)
, in an appendix to the
Flora of
Somalia
. The species name was applied to a previously unnamed species (
Commelina
sp.
#5) and the species was noted to also occur in
Kenya
,
Tanzania
,
Mozambique
,
Comoro Islands
and
Madagascar
.