Conostegia bigibbosa Cogn.

Kriebel, Ricardo, 2016, A Monograph of Conostegia (Melastomataceae, Miconieae), PhytoKeys 67, pp. 1-326 : 48-52

Conostegia bigibbosa Cogn. Fig. 67

Conostegia bigibbosa Cogn., Bull. Soc. Roy. Bot. Belg. 30: 252. 1892. Type: Costa Rica. San José: Dans la forest a General, 800 m, February 1891, A. Tonduz 3793 (holotype BR!; isotypes BR! (2), US!). Cited as Pittier 3793 in the original description.

Description.

Trees 3-15 m tall with tetragonal and ridged, glabrous to sparsely furfuraceous-puberulent stems; the nodal line conspicuous and frequently elevated, with conspicuous lenticels abaxially. Leaves of a pair equal to somewhat unequal in length. Petioles 2.7-6.5 cm, with paired projections on the abaxial surfaces at the petiole/laminar junction. Leaf blades 17-29 × 9.2-20 cm, 5-7 nerved, elliptic to elliptic ovate, obtuse to broadly rounded, abruptly acuminate, the margins undulate-denticulate, adaxially glabrous,abaxially glabrous or sparsely furfuraceous-puberulent. Inflorescence a terminal panicle 13-22 cm long branching well above the base, with accessory branches, bracts not seen, bracteoles subulate, 1-2 mm long, deciduous. Pedicel 4-10 mm long. Flowers 8 merous, calyptrate. Flower buds 7-9.2 × 6.4-9.6 mm, white, globose, rounded to flattened at the base, rounded to slightly flattened at the apex, the hypanthial and calycine portions undifferentiated, the hypanthium 5-6 × 8-9 mm, glabrescent and tuberculate. Petals 7-11.25 × 7-11 mm, pink, broadly obovate, rotate at anthesis, rounded-emarginate, glabrous. Stamens 22-26, 9-10 mm, radially arranged around the style but frequently secondarily zygomorphic because the stamens that are below the side that the style bends get stuck below the downward bent style and giant stigma, the filament 5-5.5 mm long, not geniculate, white, anthers 4-4.5 × 1.5-1.6 mm, elliptic, laterally compressed, the base sagittate, yellow, the pore 0.2-0.35 mm, terminal to slightly dorsally inclined. Ovary 15-17 locular, inferior, fluted into a glabrous dome. Style 7-8.5 mm long, bending downwards, vertical distance from the anther to the stigma ca.-0.5 - -0.25 mm, horizontal distance ca. 1 mm; stigma crateriform and lobed, 5.5-6 mm wide. Berry and seeds not seen.

Distribution

(Fig. 68 ). Endemic to the pacific side of the Cordillera de Talamanca in Costa Rica, 800-1800 m elevation.

Conostegia bigibbosa was synonimized under Conostegia oerstediana by Schnell (1996) and subsequently recognized by Almeda (2009). I here recognize it based on geographic distribution and morphological characters. Conostegia bigibbosa always has pink petals as well as two tubercles on the petiole apex which makes it unmistakable. At one point, Schnell annotated it as a subspecies of Conostegia oerstediana which is allopatric and has white petals and lacks the two tubercles at the apex of the petiole. Schnell (1996) carried out some crossing experiments between Conostegia bigibbosa and Conostegia oerstediana and Conostegia montana . He noted that fruit development was initiated when pollinating Conostegia oerstediana with pollen of Conostegia bigibbosa but not with pollen of Conostegia montana or when left unpollinated. Unfortunately he could not finish his experiment because the material was vandalized. The two species are not sympatric however and maintain the petal color difference as well as the petiole tubercle difference in natural populations.

Specimens examined.

COSTA RICA. Puntarenas: Finca Las Alturas NW of lechería, Almeda et al. 6697 (CAS, CR, NY); E.B. Las Cruces Trailhead to rio Java , Boyle et al. 6265 (CR, NY) . San José: Cantón de Pérez Zeledón, Fila Costeña, Fila Tinamastes, en la Fila del Farallón, Hammel et al. 20145 (INB, CR, NY); Aserrí, Quebrada Lajas, ca. 2.5 km al noroeste de Altos el Aguacate, Kriebel et al. 3975 (INB); Pérez Zeledon, Bajo Bonitas, Kriebel et al. 5522 (INB); Vicinity of El General , Skutch 2623 (NY) .

Figures

Figure 67. Conostegia bigibbosa. A Lenticellate internode B Tubercles on the base of the abaxial leaf surface C Inflorescence D Flowers at anthesis E Longitudinal section of a flower bud F Ventral view of a pickled flower with the petals removed and showing a stamen stuck under the stigma G Lateral view of a pickled flower with the petals removed H Longitudinal section of a hypanthium I Stamen J Style. Photos of specimen vouchered R. Kriebel 5522.

Figure 68. Distribution of Conostegia bigibbosa.