Synopsis of Commelina L. (Commelinaceae) in the state of Rio de Janeiro, reveals a new white-flowered species endemic to Brazil
Author
Pellegrini, Marco Octavio de Oliveira
https://orcid.org/0000-0002-8783-1362
Universidade de Sao Paulo, Departamento de Botanica, Rua do Matao 277, CEP 05508 - 900, Sao Paulo, SP, Brazil & Jardim Botanico do Rio de Janeiro, Rua Pacheco Leao 915, CEP 22460 - 030, Rio de Janeiro, RJ, Brazil & Current address: Smithsonian Institution, NMNH, Department of Botany, MRC 166, P. O. Box 37012, Washington D. C. 20013 - 7012, USA
marcooctavio.pellegrini@gmail.com
Author
Forzza, Rafaela Campostrini
Jardim Botanico do Rio de Janeiro, Rua Pacheco Leao 915, CEP 22460 - 030, Rio de Janeiro, RJ, Brazil
text
PhytoKeys
2017
2017-04-05
78
59
81
http://dx.doi.org/10.3897/phytokeys.78.11932
journal article
http://dx.doi.org/10.3897/phytokeys.78.11932
1314-2003-78-59
465A177298655C5FFFEDA66AFF80FFF3
576383
4.
Commelina huntii M.Pell.
sp. nov.
Figs 3
, 4
, 5
Diagnosis.
Commelina rufipes
Seub.
affinis, sed ab ea spathis depressum-ovatum vel sub-cordato, basi adnata, petalo inferioris auriculata, ovarium sparse nigro-papillose, capsulae ellipsoide dehicens, parda, seminibus libera differt.
Figure 3.
Commelina huntii
M.Pell.
A
habit
B
open spathe, showing eventual rusty cilia and villous margin
C
male flower
D
medial petal, showing auricles
E
staminode
F
lateral stamen and medial stamen
G
gynoecium, showing papillate ovary and trilobate stigma
H
capsule, showing the black papillae. Line drawings by M.O.O. Pellegrini, based on the holotype.
Figure 4.
Commelina huntii
M.Pell.
A
apex of the stem, showing terminal inflorescence
B
detail of the densely setose leaf sheath margins, with rusty hairs
C
detail of the inflorescence, showing the fused spathe and developed upper and lower cincinni
D
detail of a male flower
E
detail of the medial petal, showing the two auricles
F
detail of the androecium
G
dorsal and ventral view of the seed of the dorsal locule
H
dorsal and ventral view of one of the seeds of the ventral locules.
A
by L.S.B. Calazans,
B, C, E, G, H
by M.O.O. Pellegrini,
D
by M.S.
Waengler
and
F
by R.S. Couto.
Holotype.
BRAZIL. Rio de Janeiro: Itatiaia, Parque Nacional do Itatiaia, subida para o brejo da Lapa, beira de estrada, fl., fr., 24 January 2012, M.O.O. Pellegrini & L.S. Sylvestre 191 (RB!; isotypes: SPF!, US!).
Description.
Herbs
15-35 cm tall, perennial, terrestrial.
Roots
thin, fibrous, cream colored to light yellow, glabrous or minutely pubescent with absorbent hairs.
Stems
decumbent, apex ascending, becoming trailing or straggling, rooting only near the base; internodes 2.2-11.1 cm long, green, minutely velutine to minutely pilose, with line of uniseriate hairs opposite to the leaves, hairs hyaline.
Leaves
distichously-alternate, distributed along the stem, sessile; sheaths 1.4-2.6 cm long, pilose, hairs hyaline, margins densely setose, with a line of setose hairs opposite to the leaves, hairs rusty to rusty-brown; blades 3.3-9.1
x
(0.9-)1.6-2.3(-3.3) cm, chartaceous, adaxially dark-green to green, abaxially light-green to light-green tinted vinaceous to completely vinaceous, drying olive-green on both sides, lanceolate to ovate lanceolate, rarely ovate, adaxially scabrous, abaxially minutely villous, pilose along the midvein, hairs hyaline, base obtuse, rarely cuneate, margins green, scabrous, apex acuminate; midvein conspicuous, impressed adaxially, prominently obtuse abaxially, secondary veins (2-)4-6 pairs, adaxially conspicuous, abaxially inconspicuous.
Inflorescences
1-4, terminal or apparently so, peduncles 1.3-5.5 mm, rarely inconspicuous, puberulous with hook hairs throughout, hairs hyaline; spathes 0.7-2
x
1.4-3.2 cm, depressed ovate to subcordate, usually slightly falcate, base connate for 3-6 mm, cordate to truncate, margin green to vinaceous, minutely pilose along the edge, hairs hyaline, sometimes also ciliate, cilia rusty to rusty-brown, apex acute, internally light-green, glabrous, veins inconspicuous, externally green, minutely villous with eventual cilia, hairs hyaline, cilia rusty to rusty-brown, veins inconspicuous, becoming conspicuous when dry; upper cincinnus 2-5-flowered, flowers male, very rarely bisexual, peduncle (0.7-)1.7-2.4 cm long, exserted from the spathe, commonly arcuate at post-anthesis, sparsely to densely puberulous with hook hairs, sometimes of 2 heights, hairs hyaline; lower cincinnus 2-4-flowered, flowers mainly bisexual, sometimes male, peduncle 0.5-1 cm, glabrous or sparsely puberulous with minute hook hairs.
Flowers
bisexual or male, zygomorphic, 6.5-9 mm diam.; pedicel 1-4 mm long, light green, glabrous, reflexed and slightly elongate in fruit; sepals hyaline white to hyaline light-green, glabrous, persistent in fruit, upper sepal 3,4-4,2
x
1,1-1,4 mm, elliptic, cucullate, round apex, lower sepals 4.1-5.3
x
2.2-2.6 mm, obovate, cucullate, connate, round apex; paired petals 6.2-6.9
x
4.9-5.4 mm, clawed, limb broadly rhomboid to rhomboid-reniform, 4.7-5.3
x
4.9-5.4 mm, white, apex rounded, base cordate, claw 1.6-2 mm, white to tinted vinaceous, medial petal 3.1-4
x
1-1.4 mm, sessile, obovate to oblong-obovate, with 2 auricles near the middle, cucullate, concolorous with or slightly paler than the paired petals; staminodes 3, subequal, filaments 3-3.6 mm long, tinted vinaceous, antherodes 6-lobed, 1-1.2
x
1.2-1.4 mm, yellow with tiny light-yellow pollen sacs; lateral stamen filaments gently sigmoid, geniculate distal to the middle, 5.6-6.6 mm long, white, anthers elliptic to oblong-elliptic, 1.2-1.4
x
0.9-1.2 mm, yellowish-orange to cream-orange with margins tinted purple, pollen yellowish-orange to cream-orange; medial stamen filament straight or arcuate-decurved, decurved at the apex, 2.2-2.8 mm long, white to tinted vinaceous, anther 1.5-2.2
x
1-1.8 mm, broadly elliptic to broadly oblong-elliptic, strongly curved, held near the antherodes, yellow-orange to cream-orange, connective purple to dark-purple, pollen yellowish-orange to cream-orange; ovary oblong-ellipsoid, ca. 1-1.3
x
0.6-0.7 mm, 5-ovulate, glabrous, sparsely papillose, papillae black, style exceeding or equaling the stamens, sigmoid, strongly recurved apically, 8-11.3 mm, white, stigma trilobate, white.
Capsules
1-2 per spathe, 5.5-8.1
x
3.8-5 mm, obovoid, constricted between the seeds, brown to light brown, glabrous, sparsely papillose, papillae black, 3-locular, 2-valved, dorsal
locule
1-seeded, indehiscent, ventral locules 2-seeded.
Seeds
slightly dimorphic, dark brown with orange-brown verrucae, farinose, farina peach-colored; dorsal locule seed strongly adhered to the capsule wall, ellipsoid, strongly dorsiventrally compressed, ventrally flattened, not cleft towards the embryotega, 3.4-4.2
x
2.8-3.3 mm, testa
shallowly
foveolate, embryotega semilateral, relatively inconspicuous, without a prominent apicule, hilum linear,
1/2
the length of the seed; ventral locule seeds free from the capsule wall, ellipsoid, truncate at one end, ventrally flattened, not cleft towards the embryotega, 2.7-3.4
x
2-2.4 mm, testa foveolate, embryotega semilateral, relatively inconspicuous, without a prominent apicule, hilum linear,
1/2
the length of the seed.
Specimens seen
(paratypes).
BRAZIL. Minas Gerais: Araponga, Parque Estadual Serra do Brigadeiro, Fazenda Neblina, 17 February 2005, L.S. Leoni et al. 6112 (RB, UEC); Camanducaia, Monte Verde, Serra da Mantiqueira, 11 December 2001, L.D. Meireles & R. Belinello 775 (HURB, UEC); Delfim Moreira, Fazenda da
Onca
, trilha de subida para o Pico do Carrasco, 17 March 2011, L.L. Giacomin et al. 1429 (BHCB, RB); Lima Duarte, Parque Estadual do Ibitipoca,
Conceicao
do Ibitipoca, gruta da Cruz, 30 November 2004, E.V.S. Medeiros et al. 364 (RB); loc. cit., gruta do Cruzeiro, 20 January 2005, L.G. Temponi et al. 407 (RB, UEC); loc. cit., gruta do
Piao
, 18 January 2005, R.C. Forzza et al. 3926 (RB, UEC); loc. cit., gruta do Cruzeiro, 26 January 2010, J.C. Lopes et al. 76 (RB, SPF);
Pocos
de Caldas, Fazenda Campo da Cachoeira,
area
destinada para a
instalacao
do Jardim
Botanico
de
Pocos
de Caldas, 12 December 2001, C.N. Fraga & F.M. Fernandez 864 (RB); loc. cit., 12 December 2001, F.M. Fernandez 151 (BHZB, RB). Rio de Janeiro: Nova Friburgo, Morro da
Caledonia
, 8 June 1977, G. Martinelli 2469 (BA, RB); loc. cit., Reserva
Macae
de Cima, cerca de 900 m do Hotel
Sao
Joao
, 19 January 1999, L. Anderson et al. 99/15 (UEC); loc. cit., Reserva
Macae
de Cima, cerca de 900 m do Hotel
Sao
Joao
, 19 January 1999, L. Anderson et al. 99/20 (UEC); loc. cit., Parque Estadual dos
Tres
Picos, Vale dos Deuses, 28 January 2015, M.S.
Waengler
et al. 1565 (RB); Resende, Parque Nacional do Itatiaia, estrada BR-485,
proximo
ao km 02, 22 February 2014, L.S.B. Calazans et al. 242 (RB).
Sao
Paulo:
Itarare
, divisa entre as Fazendas Santa Andreia e Prieto, 14 May 1989, C.A.M. Scaramuzza & V.C. Souza 259 (ESA);
Ribeirao
Grande, Parque Estadual Intervales, 15 April 2003, R.A.G. Viani et al. 79 (ESA).
Etymology.
This species is named after the British botanist Dr. David R. Hunt, in honor of his extensive contribution to
Commelinaceae
systematics worldwide, especially for his contributions to
Tradescantieae
and the "
Phaeosphaerion
group" of
Commelina
.
Distribution and habitat.
Commelina huntii
was collected in moist and shaded nebular forests, generally near water bodies, in the states of Minas Gerais, Rio de Janeiro, and
Sao
Paulo, in elevations from 800 to 1,700 m above sea level (Fig.
5
). In very rare cases it can also be found in open sometimes disturbed areas.
Phenology.
It was found in bloom from November to June and in fruit from December to March, rarely in June.
Conservation status.
Despite the wide EOO (112,904.528 km2), the AOO (40.000 km2) is considerably small, since all known populations are significantly small and fragmented. Following the IUCN recommendations (
IUCN 2001
),
C. huntii
should be considered as Endangered [EN, B2b(ii, iii)c(iv)+C2a(i)] in its overall distribution.
Affinities.
Commelina huntii
can be recognized by its white flowers with auriculate medial petal and sparsely papillose ovary and capsule. It is similar to
C. rufipes
Seub.
due
to its white flowers and rusty hairs on the leaf-sheaths, but it can be readily distinguished from the latter by its connate spathe base (
vs.
free base); auriculate medial petal without medial constriction (
vs.
entire medial petal with medial constriction); light-brown, ellipsoid, dehiscent capsules (
vs.
pearly-white to silvery, globose, crustaceous capsules); and by its free, ornamented seeds (
vs.
seeds fused to the capsule septa, forming a dispersal unit, with smooth testa). The gross floral morphology of
C. rufipes
is much more similar to the
C. benghalensis
than the one of
C. huntii
, possessing only the white petals in common.
Commelina huntii
is most similar to
C. obliqua
Vahl due to its oblique leaf blades, connate spathe base, dehiscent capsules, and ventral seeds free with foveolate testa. Despite this,
C. huntii
can be distinguished from
C. obliqua
by its densely setose leaf-sheath margins with rusty to rusty brown hairs (
vs.
leaf-sheath margins long-ciliate with light to medium to dark brown to atro-vinaceous hairs); petals white (
vs.
blue to light blue to lilac to pale lilac), paired petals broadly rhomboid to rhomboid reniform (
vs.
broadly ovate to broadly ovate reniform), medial petal cucullate and biauriculate (
vs.
involute and entire); anthers of the lateral stamens light-yellow to cream with margins tinted vinaceous (
vs.
completely orange); ovary and capsules sparsely black papillate (
vs.
smooth); 1-2 capsules per spathe (
vs.
5-7); seeds with peach-colored farina (
vs.
seeds white farinose), and dorsal locule seeds with shallowly foveolate testa (
vs.
rugose foveolate testa).
Figure 5.
Distribution map of
Commelina huntii
M.Pell.
Figure 6.
Commelina singularis
Vell.
A-B
Original plate of
Vellozo's
C. singularis
:
A
line drawings of habit, inflorescence and floral characters
B
detail of floral characters.
C
, photos of a natural population of
Tripogandra diuretica
from the Jardim
Botanico
Rio de Janeiro, RJ: detail of the inflorescence, showing flowers with white corolla
D-E
photos of
T. diuretica
from the municipality of
Petropolis
, RJ:
D
detail of floral characters of a flower with lilac corolla
E
detail showing the leaves (note the parallel venation characteristic of the species)
SS
sterile stamens;
FS
fertile stamens;
Gy
gynoecium. Photo of
C. singularis
plate from Biodiversity Heritage Library; All field photos by M.O.O. Pellegrini.