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 macrantha O. Berg ex Triana
Fig. 86
Conostegia
macrantha
O. Berg ex Triana, Trans. Linn. Soc. London 28: 97. 1872. Type: Costa Rica. San
Jose
: Candelaria, no date, A. Oersted 12 (lectotype: BR!, designated here; isolectotypes (fide
Schnell (1996)
: C, GH, as well as a photo of a lost specimen from B at F!).
Description.
Trees 3.5-15 m tall with thick tetragonal and ridged stems that are glabrous or furfuraceous on new growth with sessile stellate trichomes; the nodal line conspicuous and sometimes setulose in young branches, lenticellate abaxially. Petioles 1-7 cm long. Leaves of a pair equal to somewhat unequal in length. Leaf blades 6.7-30
x
2.3-15 cm, 5 nerved or slightly plinerved, ovate to elliptic, the base acute to obtuse, the apex obtuse and acute to acuminate, the margin entire or denticulate, adaxially glabrous, abaxially with branched and stellate hairs on the veins. Inflorescence a
terminal
panicle 6-21.2 cm long branched above the base but sometimes appearing branched at the base because of multiple inflorescences arising at opposing meristems at the terminal node, accessory branches present, rachis tetragonal, accessory branches present, bracts early deciduous or absent, the rachis glabrous or furfuraceous with sessile stellate trichomes these sometimes minute and inconspicuous, bracteoles linear, ca. 2 mm long, deciduous. Pedicels 4-15 mm, frequently nodding. Flowers 7-10 merous, calyptrate. Floral buds 8-15
x
7-13.5 mm, spherical, the base rounded, the apex rounded and mucronate, not constricted, the hypanthial and calycine portions little differentiated; hypanthium 9.5-10
x
13-14 mm, glabrous or beset with small sessile stellate trichomes, strongly tuberculate. Petals 9.5-16
x
12-14.5 mm, white, obovate, spreading, the apex retuse, glabrous. Stamens 28-45, 9-11 mm long, radially arranged around the style, occasionally secondarily zygomorphic resulting from some stamen getting stuck below the stigma, the filament 5.25-5.7 mm, white, anthers 4.5-5
x
1.75-2.25 mm, oval, yellow, the base sagittate, strongly laterally compressed, the pore 0.2-0.3 mm, terminal. Ovary 18-25 locular, inferior, the apex glabrous and forming a collar around the style; style 7-8 mm long, usually straight but sometimes slightly curving, distance from the anther to the stigma ca. -2 - 0 mm, stigma crateriform, consisting of 18-25 laterally compressed lobes, 6.5-8 mm wide. Berry 14-18
x
10-12 mm, purple. Seeds 0.5-1 mm long, narrowly ellipsoid, the testa smooth.
Figure 86.
Conostegia macrantha
.
A
Leaf abaxial foliar surface
B
Inflorescence
C
Lateral view of flower at anthesis
D
Frontal view of flower at anthesis
E
Close up of the surface of the hypanthium
F
Longitudinal section of a hypanthium of a flower at anthesis with its parts removed
G
Petal
H
Stamen
I
Style
J
Stigma. Photos of specimen vouchered
R. Kriebel 5406
.
Distribution
(Fig.
87
). Endemic to Costa Rica, 1300-3000 m elevation.
Figure 87.
Distribution of
Conostegia macrantha
.
Conostegia macrantha
can be recognized by its stout branches, stellate indument on abaxial leaf surface, and large flowers with crateriform, straight styles, and retuse petals. Flowers of this species have a good fragrance (i.e.,
Chavarria
817
,
Jimenez
626
-both at MO). This species is also reported from northern Panama by
Schnell (1996)
but I have not seen any Panamanian specimens. The few specimens from Panama that resemble
Conostegia macrantha
are glabrous, the reason why I did not include them in the distribution of this species presented here.
Schnell (1996)
noted that the species is especially common in the volcanoes surrounding the central valley of Costa Rica and is mostly restricted to that area. Specimens collected near Barva and Poas volcano for this study have the typical straight styles of
Conostegia macrantha
.
Schnell (1996)
noted some specimens from Vara Blanca showed evidence of introgression from
Conostegia oerstediana
in their smaller flowers.
Specimens examined.
COSTA RICA
.
Alajuela
:
Near Continental Divide
, vicinity of
Vara Blanca
,
Chrysler
5348 (NY);
Alfaro Ruiz
hills above laguna,
Smith
10075 (NY)
.
Cartago
:
Volcan
Turrialba
on road
between
Lecheria
La Central and La Trinidad, Schnell
1077 (MO, NY); south slope of
Turrialba Volcano
above Santa Cruz, Williams 19677 (NY); near
La Sierra
, about
25 km
south of
Cartago
,
Cordillera de Talamanca
,
Williams
et al. 28022 (NY)
.
Heredia
:
Sacramento
,
Finca Ingrid Steinvorth
,
Kriebel
5406 (INB, NY); near
Rio
Las Vueltas N.E.
of
Volcan
Barba
,
Lent
2644 (CR, NY)
.
San
Jose
:
San
Cristobal
Norte
,
Desamparados
,
Antonio
706 (CR, NY);
Property of Hacienda Forestales
above
Cascajal
,
Lumer
1301 (NY); NE of
Coronado
,
Chrysler
5348 (NY);
Riviera
de los
Arcangeles
,
Escazu
,
Pittier
13053 (NY)
.