Macropsychanthus nitidus: a new rank and combination for dioclea rostrata var. nitida (leguminosae, papilionoideae)
Author
Fonseca-Cortés, Andrés
Programa de Pós-graduação em Botânica, Universidade Estadual de Feira de Santana, Departamento de Ciências Biológicas. Av. Transnordestina s. n., Novo Horizonte, 44036 - 900, Feira de Santana, Bahia, Brazil
Author
Snak, Cristiane
Departamento de Engenharia de Pesca e Ciências Biológicas, Universidade do Estado de Santa Catarina, Rua Cel. Fernandes Martins 270, Progresso, 88790 - 000, Laguna, Santa Catarina, Brazil
Author
Queiroz, Luciano Paganucci De
Programa de Pós-graduação em Botânica, Universidade Estadual de Feira de Santana, Departamento de Ciências Biológicas. Av. Transnordestina s. n., Novo Horizonte, 44036 - 900, Feira de Santana, Bahia, Brazil
text
Phytotaxa
2023
2023-10-11
619
4
293
298
http://dx.doi.org/10.11646/phytotaxa.619.4.4
journal article
273556
10.11646/phytotaxa.619.4.4
23c24574-7292-4d58-bfff-85851b6a09a8
1179-3163
8430575
Macropsychanthus
Harms ex Schumann & Lauterbach (1900: 366)
originally comprised four species confined to Southeastern Asia to New
Guinea
(Adema, 1998). Recently,
Queiroz & Snak (2020)
has demonstrated that
Dioclea
Kunth (1824: 437)
is a non-monophyletic genus, with its species falling into three different positions: (1) the puzzling species,
Dioclea paniculata
Killip ex R.H.
Maxwell (1978: 243)
, was highly supported as a member of the Galactia clade; (2)
Dioclea
subg.
Dioclea
appeared as sister to a clade composed of
Cleobulia
Bentham (1837: 67)
and
Cymbosema
Bentham (1840: 61)
; and (3) the species of
Dioclea
subgenera
Pachylobium
and
Platylobium
composed a paraphyletic grade, nesting the genera
Luzonia
Elmer (1907: 220)
and
Macropsychanthus
.
Therefore, they proposed that the circumscription of
Dioclea
should be restricted to
Dioclea
subg.
Dioclea
,
with 13 species and that the limits of
Macropsychanthus
should be widened to include the genus
Luzonia
,
as well as the
Dioclea
subgenera
Pachylobium
and
Platylobium
.
Under the current circumscription,
Macropsychanthus
Harms ex K. Schumann & Lauterbach (1900: 366)
comprises ca. 50 species, with a pantropical distribution, mainly confined to the Neotropics (
Queiroz & Snak 2020
). The genus is characterized by its lianescent habit, erect pseudoracemose inflorescences composed of secundiflorous brachyblasts, bicallosal standard petals and turgid or laterally compressed fruits (
Queiroz & Snak 2020
). Phylogenetic studies on the genus supported the presence of two clades, recognized as subgenera by
Queiroz & Snak (2020)
: subgenus
Macropsychanthus
and subgenus
Platylobium
.
The subgenus
Platylobium
is restricted to South America and is characterized by basifixed triangular stipules, leaves lacking stipels, laterally compressed fruits and elastically dehiscent, and seeds with circular hilum.This subgenus includes nine species:
Macropsychanthus bicolor
(Benth.) L.P. Queiroz & Snak, (2020:105)
M. coriaceus
(Benth.) L.P.
Queiroz & Snak (2020:106)
,
M. duckei
L.P.
Queiroz & Snak (2020:106)
,
M. erectus
(Hoehne) L.P.
Queiroz & Snak (2020:106)
,
M. hispidimarginatus
(R.H. Maxwell) L.P.
Queiroz & Snak (2020:106)
,
M. macrocarpus
(Huber) L.P.
Queiroz & Snak (2020:107)
,
M. rigidus
(R.S. Cowan) L.P.
Queiroz & Snak (2020:107)
,
M. ruddiae
(R.H. Maxwell) L.P.
Queiroz & Snak (2020:107)
, and
M. scabrus
(Rich.) L.P.
Queiroz & Snak (2020:107)
(
Queiroz & Snak, 2020
).
Bentham described
Dioclea rostrata
Benth. (1837:69)
. Later, in the Flora Brasiliensis,
Bentham (1859)
introduced a new variety:
D
.
rostrata
var. “β”
nitida
,
only known from the
type
collection. A detailed morphological analysis of
type
collections and the specimens of this subgenus revealed the presence of more collections of this taxon, mainly identified as
Dioclea bicolor
. Here we propose a new combination and a new rank for
D. rostrata
var.
nitida
, including complete description, illustration, distribution, and comparison within the morphologically similar species.