A new species of Goniothalamus (Annonaceae) from Palawan, and a new nomenclatural combination in the genus from Fiji
Author
Tang, Chin Cheung
School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
Author
Xue, Bine
School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
Author
Saunders, Richard M. K.
School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, P. R. China
saunders@hku.hk
text
PhytoKeys
2013
2013-12-18
32
27
35
http://dx.doi.org/10.3897/phytokeys.32.6663
journal article
http://dx.doi.org/10.3897/phytokeys.32.6663
1314-2003-32-27
FF94645BFFB8FFEEFFD8FFAFFFF25949
576194
Goniothalamus angustifolius (A.C.Sm.) B. Xue & R.M.K.Saunders
comb. nov.
Basionym.
Polyalthia angustifolia
A.C.Sm., Bull. Torrey Bot. Club 70: 538. 1943. Type: FIJI: Viti Levu,
J.W. Gillespie 2198
(holotype: A!; isotypes: BISH, GH!).
Discussion.
The historical delimitation of the genus
Polyalthia
has been shown to be highly polyphyletic, and large-scale taxonomic realignment and recognition of new genera has been undertaken to ensure strict monophyly of genera (
Mols et al. 2008
;
Saunders et al. 2011
;
Xue et al. 2011
,
2012
,
in press
;
Chaowasku et al. 2012
). As part of this series of taxonomic revisions, chloroplast DNA regions were sequenced from eight species from the Melanesian island of Fiji (Xue, 2013) that had previously been assigned to
Polyalthia
. Phylogenetic analysis of this data revealed that most of these species align with either
Hubera
(
Chaowasku et al. 2012
;
Xue 2013
) or
Meiogyne
(
Xue 2013
;
Xue et al. in press
), although one species,
Polyalthia angustifolia
A.C.Sm., which was sequenced from the type material, is nested within the
Goniothalamus
clade (
Xue 2013
).
Polyalthia angustifolia
was originally described from fruiting material (
Smith 1943
), and it is likely that its incorrect generic affiliation was due to the absence of flowers, which are very different in
Polyalthia
and
Goniothalamus
. Subsequent phylogenetic analyses with a larger taxon sampling (C.C. Tang et al., unpubl.) have revealed
Polyalthia angustifolia
as sister to the Fijian species
Goniothalamus monospermus
(Baill.) R.M.K.Saunders with strong support (posterior clade probability = 1; bootstrap support = 96%); these two species are morphologically distinct, as
Polyalthia angustifolia
seeds lack the broad lateral testa wings that are diagnostic of
Goniothalamus monospermus
(
Van Setten and Koek-Noorman 1992
: pl. 39i). The transfer of the name
Polyalthia angustifolia
to
Goniothalamus
is accordingly validated here.