Conostegia osaensis (Aguilar, Kriebel & Almeda) Kriebel, 2016

Kriebel, Ricardo, 2016, A Monograph of Conostegia (Melastomataceae, Miconieae), PhytoKeys 67, pp. 1-326 : 201

Conostegia osaensis (Aguilar, Kriebel & Almeda) Kriebel comb. nov. Fig. 178

Conostegia osaensis (Aguilar, Kriebel & Almeda) Kriebel. Basionym: Miconia osaensis Aguilar, Kriebel and Almeda, Proc. Calif. Acad. Sci. Series 4, 59(10): 490, f. 1A-J, 2A-D. 2008. Type: Costa Rica. Puntarenas: Cantón de Osa, Reserva Forestal Golfo Dulce, entrada a Chocuaco, por la casa de Moncho, 200-350 m, 28 May 1997, R. Aguilar 5145 (holotype: INB!; isotypes: CAS!, CR!, MO!, USJ).

Description.

Trees 9-25 m tall with the uppermost flattened and two sided branchlets completely covered with a stellulate-lepidote indumenta; the nodal line present. Leaves of a pair equal to subequal in size. Petioles 1.5-4.5 cm long. Leaf blades 7.5-21 × 3-7 cm, 5-plinerved, with the innermost pair of primary veins diverging ca. 0.5-1.5 cm above the blade base in opposite, alternate or subalternate fashion, elliptic to elliptic-oblong or slightly elliptic-lanceolate, the base acute, the apex acute to acuminate, the margin entire to inconspicuously crenulate-denticulate, the adaxial surface glabrous and inconspicuously glandular puncticulate, the abaxial surface completely covered by peltate scales. Inflorescence a terminal panicle 10.8-15 cm long branching above the base, accessory branches present, reddish stellulate-lepidote indument throughout; bracts and bracteoles 1-1.5 × 0.25-0.5 mm, triangular, persistent. Pedicels 0.25-0.5 mm. Flowers 5-merous, calyx calyptrate, flower buds 3-4.5 × 2-2.75 mm, elliptic-ovate, calyx teeth, the base rounded, the apex acute, not constricted, the hypanthial and calyptrate portions differentiated in texture, color and indument different, the calyptra being white or translucent, very thin and more sparsely pubescent than the hypanthium, the latter campanulate to urceolate, 2.5-3 × 2.25-2.75 mm, densely covered with peltate scales that grade into stellate hairs, the torus also beset with scales. Petals 5-8 × 3-6 mm, white, obtriangular, spreading at anthesis, emarginate at the apex, glabrous. Stamens 10, Stamens ca. 5-8 mm long, androecium slightly bilaterally symmetric, the filaments 2.5-4.5 mm, white, 3.25-3.75 × 1-1.5 m, oblong, yellow, laterally compressed, the connective dorsally thickened, the pore ca. 0.2 mm wide, slightly ventrally inclined. Ovary 5-locular, inferior, apically glabrous and slightly ribbed, forming a low collar around the style base, with pronounced elevated lines. Style ca. 5 mm long, straight and abruptly curved near the apex, vertical distance from the anther to the stigma ca. 0-0.5 mm, stigma punctiform to truncate, ca. 0.8 mm wide. Berry ca. 6 × 6 mm, purple black. Seeds 1.3-1.9 mm long, broadly pyramidate, rounded to bluntly angled on the convex face, the testa smooth.

Distribution

(Fig. 179 ). Endemic to the Osa Peninsula in southern Costa Rica, 40-200 m in elevation.

Conostegia osaensis is endemic to the Osa Peninsula of Costa Rica and quite distinctive as it tends to be a large tree up to about 25 m tall. In addition, the leaf abaxial surface is covered with a stellate lepidote indument and the flowers are calyptrate, not pleiostemonous, and have a short style. In the molecular phylogeny Conostegia osaensis falls sister to the clade comprised of Conostegia plumosa , Conostegia speciosa , Conostegia subcrustulata , and Conostegia xalapensis . With these taxa Conostegia osaensis shares the calyptrate calyx and the short style. Conostegia osaensis has the largest seeds of any species in Conostegia .

Specimens examined.

COSTA RICA. Puntarenas: Rincón, cerca de Banegas, 1 km al este del centro del pueblo de Banegas, Estación Biológica Los Charcos, sendero Dendrobates, Aguilar 10200, 10228 (INB); Mogos, Bahía Chal, entrada a Chocuaco a 35 km de Chacarita, finca de Carlos Rojas, Aguilar 6208 (INB).

Figures

Figure 178. Conostegia osaensis. A Habit and detail of leaf abaxial surface B Flowering branch C Close up of the flower D Infructescence. Photographs taken Reinaldo Aguilar and vouchered R. Aguilar 10200.

Figure 179. Distribution of Conostegia osaensis.