A Monograph of Conostegia (Melastomataceae, Miconieae)
Author
Kriebel, Ricardo
Department of Botany, University of Wisconsin-Madison, 430 Lincoln Drive Madison, Wisconsin 53706, USA
kriebelr@gmail.com
text
PhytoKeys
2016
2016-07-20
67
1
326
http://dx.doi.org/10.3897/phytokeys.67.6703
journal article
http://dx.doi.org/10.3897/phytokeys.67.6703
1314-2003-67-1
D846EB3F7746FFFE4A469751FFEF3B22
133270
Conostegia
brenesiana Kriebel
nom. nov.
Fig. 137
Conostegia
brenesiana
Kriebel. Based on:
Miconia brenesii
Standl, Field Mus. Nat. Hist, Bot. Ser. 18: 816. 1938. Type: Costa Rica. Alajuela: Santiago de San
Ramon
, January 1937, A. Brenes 21981 (holotype: F!, isotypes: CR!).
Description.
Small trees 1.5-10 m tall with rounded-quadrate stems that are moderately to sparsely ferrugineous scurfy or stellulate-puberulent, to almost glabrous; the nodal line present but inconspicuous. Leaves at a node equal to unequal in length. Petioles 0.4-2 cm. Leaf blades 4-14.4
x
1.2-4.7 cm, 3-5 plinerved, with the innermost pair of primary veins diverging from the midvein 0.4-2 cm above the base in opposite or generally alternate fashion, elliptic, the base acute to obtuse and typically asymmetrical, the apex attenuate to acuminate, the margin entire to distally crenulate, the adaxial surface glabrous, the abaxial syrface glabrous on the surface and scurfy puberulent to glabrous on the veins, frequently with white dots irregularly spread on the lamina. Inflorescence a terminal panicle 2.8-7.5 cm long branching at or above the base, the rachis glabrous to scurfy puberulent, the branches very thin, the bracteoles 0.5-1 mm, narrowly triangular to subulate, persistent and fused basallly forming a shallow inconspicuous nodal collar or elevated ridge. Pedicels 0.5-2 mm. Flowers 5 merous, not calyptrate, floral buds 1.5-3.75
x
0.9-2.0 mm, the hypanthuim 1.5-2
x
1.25-1.75 mm, scurfy puberulent, calyx tube ca. 0.1 mm long, the calyx lobes depressed undulate, 0.5
x
1 mm, the calyx teeth bluntly triangular, 0.25 mm long, equaling or barely exceeding the calyx lobes. Petals 1.5-2.5
x
1-1.5 mm, white, oblong, glabrous reflexed, emarginate. Stamens 10, 2-2.5 mm long, actinomorphic, the filaments 1.25-1.75 mm, with a geniculation near the middle, white, anthers 0.5-1
x
0.25-0.55 mm, cuneate in outline and widest at the apex, white or yellow, the connective prolonged briefly below thecae, the pore subterminal ca. 0.3 mm wide, dorsally inclined. Ovary 5 locular, inferior, glabrous or scurfy puberulent apically. Style 3.25-4 mm long, straight, vertical distance from stamens to stigma ca. 0.5-1 mm, horizontal distance absent, the stigma punctiform to truncate, ca. 0.35 wide. Berry 4.25-5.25
x
4.25-5.25 mm, purple black. Seeds 0.34-0.5 mm long, more or less pyramidal, frequently asymmetrical.
Figure 137.
Conostegia brenesiana
.
A
Branch showing plinerved leaf venation with slightly asymmetrical venation
B
Leaf abaxial surface showing strongly asymmetrical leaf venation
C
Inflorescence
D
Close up of the flower
E
Flower buds and subtending bracteoles
F
Longitudal section of a flower bud with the style removed
G
Pickled flower
H
Longitudal section of a flower
I
Close up of the ovary apex. Note brown glands in the inner hypanthium wall and ovary apex
J
Petal
K
Stamen side view
L
Stamen ventral view
M
Style. Photographs
A-D
taken by Kenji Nishida
E-M
from photographs of specimen vouchered
R. Kriebel 3665
.
Distribution
(Fig.
138
). Endemic to cloud forests in Costa Rica from 550-2100 m elevation.
Figure 138.
Distribution of
Conostegia brenesiana
.
The epithet
brenesiana
was chosen for this species because
brenesii
is preempted by
Conostegia brenesii
Standl.
Conostegia brenesiana
can be recognized because of its almost glabrous vegetative parts, plinerved leaves frequently with asymmetric venation, wiry inflorescences with persistent bracteoles and small five merous flowers. In addition, this species has the widest anther pores in
Conostegia
and some of the smallest anthers.
Almeda (2009)
reports the ovary of this species as glabrous. The specimen I studied from spirit had small glands suggesting intraspecific variation. Further observations should be made in this species considering it is also variable in anther color.
Some
specimens report the flowers as totally white while others report the anthers as yellow. An interesting aspect of this variation concerns the possible transition of pollination systems in this species.
Conostegia brenesiana
inhabits cloud forests mainly at middle elevation but spanning a broad range. An interesting hypothesis to test is if the more white flowers occur at higher elevations where the buzz pollinated species tend to decline. The species already presents the broad anther pores which in themselves hint to a transition that might be happening. One specimen from Cerro Hornito in western Panama (
Kriebel and Burke 5752
) might represent this species but the inflorescence is too immature to tell.
Specimens examined.
COSTA RICA
.
Alajuela
: La Palma de San
Ramon
, Brenes 5232, 6768 (CR, NY); Los Angeles (Silencia) de San Ramon, Brenes 17081 (CR, NY); San Pedro near San Ramon, Brenes 5052 (NY); Cerro de San Rafael de San Ramon, Brenes 22414 (CR, NY); Reserva forestal San
Ramon
, slope above and in the valley of the
Rio
San Lorencito, Burger et al. 12130 (CR, MO, NY); Guatuso, P.N.
Volcan
Tenorio
, Cuenca del
Rio
Frio
, Alto Masis, Chaves and
Munoz
361 (CR, INB, MO, NY);
Estacion
Rio
San Lorenzo, Kriebel 931 (INB); Finca La Paz, San
Ramon
, Kriebel 1477 (INB, NY); Alfaro Ruiz, P. N. Juan Castro Blanco, Cuenca alta del
Rio
La Vieja, Solano and Cerling 2696 (INB, NY).
Cartago
: Kiri Lodge, Sendero el
Colibri
, Kriebel 3665 (INB, MO, NY).
Guanacaste
:
Estacion
Biologica
Cacao, Trail to Cacao summit aprox.
1 km
from station alongside trail, Boyle 7203 (INB, NY); P.N. Guanacaste, Sector Cacao, Kriebel et al. 879 (INB);
Estacion
Pitilla, sobre la fila al Cerro Orosilito, Robles et al. 2815 (INB, MO).
Heredia
: Santa
Barbara
, Posada
Volcan
Poas
, Kriebel 1255 (INB, NY); Vara Blanca de
Sarapiqui
north slope of Central Cordillera between
Poas
and Barba volcanoes, Skutch 3455 (CR, NY);
9 km
NO de Varablanca hacia finca Murillo, Proyecto ALAS, Solano,
Gonzalez
and
Santamaria
2134 (INB, NY).
Puntarenas
: Cordillera de
Tilaran
, San Luis,
Rio
Veracruz, Monteverde, Fuentes 690 (CR, MO).
San
Jose
: San
Jeronimo
de Moravia,
2 km
NE del peaje, en el
limite
con el P. N. Braulio Carrillo, Kriebel 1113 (INB) forest near
Rio
Hondura, Lent 1352 (CR, MO, NY); P. N. Braulio Carrillo, Faldas del cerro junto al
Rio
Zurqui
, Sector Santa Elena, Vargas and Castillo 3473 (INB, NY).