Dichorisandra flesheri (Commelinaceae), a new delicate species from South Bahia, Brazil
Author
Aona, Lidyanne Y. S.
Universidade Federal do Recôncavo da Bahia (UFRB), Cruz das Almas, Bahia, Brazil
Author
Souza, Everton Hilo De
Universidade Federal do Recôncavo da Bahia (UFRB), Cruz das Almas, Bahia, Brazil
Author
Bittrich, Volker
Universidade Estadual de Campinas (UNICAMP), Instituto de Biologia, Departamento de Biologia Vegetal, Campinas, SP, Brazil
Author
Do Amaral, Maria Do Carmo E.
Universidade Estadual de Campinas (UNICAMP), Instituto de Biologia, Departamento de Biologia Vegetal, Campinas, SP, Brazil
text
Phytotaxa
2024
2024-05-09
647
2
199
206
http://dx.doi.org/10.11646/phytotaxa.647.2.6
journal article
302776
10.11646/phytotaxa.647.2.6
1110289e-5419-4fc4-995d-26550466e5d1
1179-3163
13215678
Dichorisandra flesheri
Aona
,
sp. nov.
(
Fig. 2
)
Type
:—
BRAZIL
.
Bahia
:
Igrapiúna
,
Reserva Ecológica Michelin
,
Mata da Vila
5, 13˚49’18”S, 39˚11’54” W,
132 m
.
a.s.l.,
25 November 2022
(fl),
E.H.Souza
2500
P.L.Ribeiro
;
R.R.N.França
;
S.S. Mota
;
G.M.D.Ferreira
;
A.Caetité
;
G.Q.Nascimento
(
holotype
HURB
!)
.
Diagnosis:
—
Dichorisandra flesheri
is distinguished from its congeners by the well‒developed indument on stem, sheaths, both sides of the leaf blades, a pendulous inflorescence, inflorescence and flower buds, for presenting six stamens with yellow anthers opening by longitudinal slits, and by the ovoid capsules with a sometimes verrucose epicarp, and apical pubescence.
Description:
—Single stemmed erect herbs, to
20‒40 cm
tall. Stem densely pilose, with
3‒4 mm
long brownish trichomes, internodes
3‒9 cm
long at the base, reduced towards the apex. Leaves subrosulate or spirally arranged, sheaths
1.7‒3 cm
long, reduced towards the apex, densely pilose, often with pale vinaceous streaks, lower sheaths caducous, distally covered with trichomes,
3‒4 mm
long, whitish to brownish, petiole
4‒5 mm
long, or inconspicuous; leaf elliptic or orbicular, 14.5‒24.5 ×
7‒14.5 cm
, discolorous, abaxial surface light green, adaxial surface light green or faintly vinaceous, pilose on both surfaces, trichomes
3‒4 mm
long, whitish or brownish, margin ciliate, base attenuate, apex acuminate, primary vein conspicuously sulcate on the adaxial face
in vivo
. Inflorescence terminal, congested pendulous; basal bract leaf-like, peduncle
5.5‒9.5 cm
long, densely pilose; cincinni peduncle
0.5‒1 mm
long, pilose, becoming shorter towards the apex, with 6‒10 cincinni, subsessile, congested, with 4–6 flowers each, bracts linear, (6‒)9–30 ×
1.5‒4 mm
, reduced towards the apex, oriented parallelly to the cincinni rachis, apex curved, pale green, turning scarious over time, abaxial side pilose, trichomes
1.5‒3 mm
long, whitish, internally pilose, margin ciliate, bracteoles
ca.
10‒12 ×
3 mm
, scarious, externally villous, margin ciliate. Flowers with densely pilose,
ca.
3–7 mm
pedicels, buds ovoid or ellipsoid, 18–22 ×
3–4 mm
, villous; flowers either bisexual or male, petals deliquescent, androecium slightly zygomorphic,
3–3.5 cm
diam.; sepals linear to elliptic, 12–15 ×
3–4 mm
, whitish with purplish margin, hyaline, internally densely pilose, externally glabrous; petals ovate, 1.6–1.7 ×
1–1.5 cm
, partly blueish and whitish; stamens 6, slightly unequal, directed towards the center and upper part of the flower, filaments
1–1.5 mm
long, whitish, erect, anthers
4–5 mm
long, oblong, slightly sagittate at base, yellowish, opening introrsely with longitudinal slits, but functionally poricidal; ovary globose,1.5–2 ×
1–1.5 mm
, glabrous to pubescent; style
7–8 mm
long, whitish, purplish in the upper third, erect, apex curved, stigma trilobed; ovules 4–6 per cell, greenish-yellowish. Capsule ovoid, (10-)20–21 ×
5–7 mm
, greyish when immature, pubescent at the apex, epicarp sometimes verrucose.
Seeds
not seen.
Etymology
:
—
The specific epithet honors the ecologist Dr. Kevin Michael Flesher, Director of the Reserva Ecológica Michelin (REM) and responsible for the conservation, and research management of the area where this new species was discovered.
Phenology
: Collected with flowers from November to June and with fruits in April.
Distribution and habitat
:
—
Dichorisandra flesheri
has been collected so far in the southern
Bahia state
, municipalities of Camamu, Igrapiúna and Ubaitaba (
Fig. 1
). The species occurs only in the Atlantic Forest, in the phytophysiognomy of the Dense Ombrophilous Forest, occurring mainly on river banks, associated with rocky outcrops in the Reserve.
Additional Specimen Examined (
Paratypes
)
:
—
BRAZIL
.
Bahia
:
Acaraó
,
Rod.
lado
Sul
,
02 June 1971
(fl.),
T.S. Santos
1724
(
CEPEC
)
;
Camamu
,
Rodovia Travessão
/
Camamú
,
Km
33,
Ramal
à direita para a
Fazenda Brahma
, 14˚00’S, 39˚13’W,
15 June 1979
(fl.),
L.A.M. Silva
499 et al.
(
CEPEC
)
;
ibid
., Rod. BA 650
Camamu
/
Travessão
, entrada a 15.7
Km
da sede municipal, Fazenda Zumbi dos Palmares (assentamento)
ca.
1km
da rodovia,
ca.
6.3
Km
da vicinal para a
Fazenda Dandara
, 14˚0’54”S, 30˚08’20”W,
22 February 2000
(fl.),
J.G. Jardim
2765 et al.
(
CEPEC
,
NY
);
ibid
.,
Faz. Exílio
, entrada no Km 10.7 da BA-650 Camamú/Travessão,
ca.
2 Km L da sede da fazenda, 14˚00’7”S, 30˚10’7”W,
21 February 2000
(fl.),
J.G.Jardim
2709,
A.Aguiar
,
S.C.S’Antana
,
F.Junchum
&
J.Paixão
(
CEPEC
)
;
ibid
., trilha a partir da portaria da
Faz. Bhrama.
14˚9’5,7”S, 39˚21’4,7”W,
2 February 2006
(fl.),
L.Y.S. Aona
987,
A.S.B. Gil
& E.
Meirelles
(
ALCB
,
HURB
,
UEC
)
;
Igrapiúna
,
Reserva Michelin
, entrada da
Mata da Vila
5,
Trilha do Gigó
, 13˚49’18”S, 39˚11’54”W,
5 April 2013
(fr.),
L.Y.S. Aona
2550 & turma
de Biologia
floral
(
HURB
)
;
Ubaitaba
,
Km
8 da BR 101 ao
Norte
,
16 June 1972
(fl.),
T.S. Santos
2309
(
CEPEC
)
.
IUCN Threat Assessment:
—
The suggested conservation status for
Dichorisandra flesheri
is Endangered (EN) B1a(iv)+2ab(i,iii); D. The species was estimated to have an Extent of Occurrence (EOO) of
241,436 km
2
and an Area of Occupancy (AOO) of
32,000 km
2
. All specimens of
Dichorisandra flesheri
were collected from forest remnants, occupying the understory of moist forests in southern
Bahia
. In the area of occurrence, cocoa (
Theobroma cacao
L.) and rubber tree (
Hevea brasiliensis
L.) plantations are common, eliminating most of the understory vegetation, for the planting of these crops.
Aona-Pinheiro
et al.
(2012)
pointed out that the cocoa and rubber tree cultivation system in the region has been decreasing in recent years, while livestock activity has increased considerably. It is worth noting that the most conserved populations are within the Reserva Ecológica Michelin (REM), a private area maintained by the Michelin company. The REM area was deeply affected by logging between the 1960s and 1970s, however, it was later transformed into a private protected area without logging activities. The known populations within the REM have few individuals (ca. 10), presenting slow growth, flowering only once a year. Recently,
Souza
et al.
(2021)
and
Souza & Leme (2021)
described new species of
Bromeliaceae
in the REM in the same area of occurrence of
Dichorisandra flesheri
, reinforcing the importance of floristic studies in southern
Bahia
.
FIGURE 2.
Dichorisandra flesheri
.
A.
Habit.
B
. Stem with sheaths (sh) and inflorescence and its peduncle (pd) in detail.
C.
Detail of inflorescence showing peduncles (pd) and floral buds (fb) with trichomes (tr) and immature fruit (fr).
D.
Bisexual flower showing the anthers (an) with style (st), gynoecium, petals (pe) and sepals (se).
E.
Flower with detail of anthers (an) and style.
F.
Inflorescence with fruits.
G.
Detail of fruits showing pubescent, slightly verrucose surface.
H.
Details of roots and rhizomes (rh) and stem (sm).
Notes:
—
Dichorisandra flesheri
can be identified by the well‒developed indument present on stems, sheaths, both sides of the leaf blades, inflorescence, floral buds and the abaxial surface of the sepals, for presenting six stamens with yellow anthers opening by longitudinal slits – a unique character combination within the genus (
Fig. 2
). Furthermore, the adaxial surface of the young leaf blades presents white longitudinal striations and the secondary and primary veins are adaxially clearly sulcate, abaxially salient.
The inflorescence of this new species is pendulous (
Figs. 2B, F
), an unusual feature in the genus. Only
Dichorisandra incurva
Martius ex
Schultes (1830: 1184)
,
D. glabrescens
(
Seubert 1855: 233
) Aona & Amaral (2016: 7)
,
D. penduliflora
Kunth (1843: 114)
and
D. nutabilis
Aona & Amaral (2012: 18)
have pendulous inflorescences. However,
D. incurva
has white flowers (
vs.
purplish in
D. flesheri
) and its fruits are cylindrical, surface smooth (vs. ovoid, surface pubescent at the apex, slightly verrucose in
D. flesheri
) (
Fig. 2G
).
Dichorisandra glabrescens
is a climbing herb up to
2 m
high (
vs.
erect herb up to
40 cm
in
D. flesheri
) (
Fig. 2A
), petals pale blue to lilac (
vs
. purplish in
D. flesheri
,
Fig. 2D
), with fruits very similar to those of
D. incurva
(see above).
Dichorisandra penduliflora
presents leaves distichally disposed along the stem and the flowers have 5 stamens with whitish anthers, apex and center blue to purplish (vs. rosette or spirally disposed (
Fig. 2A
) arranged and 6 stamens with anthers yellowish (
Fig. 2E
) in
D. flesheri
.
Dichorisandra nutabilis
have stamens with purplish anthers, dehiscing by 1 apical pore (
vs.
stamens with anthers yellowish, opening introrsely with longitudinal slits (functionally poricidal) in
D. flesheri
).
Regarding the yellowish stamens, opening introrsely with longitudinal slits (functionally poricidal) in the genus
Dichorisandra
, the species
D. glaziovii
Taubert (1890: 2)
(
Fig. 4A
),
D. saxatilis
Aona & Amaral (2016: 68)
(
Fig. 4B
),
D. sagittata
Aona & Amaral (2016: 1)
(
Fig. 4C
),
D. velutina
Aona & Amaral (2012: 15)
(
Fig. 4D
) and
D. striatula
Moraes & Pellegrini (2019: 783)
show these same characteristics, but they can be distinguished from
D. flesheri
according to the characters shown in
Table 1
.