Conostegia dissitiflora (Almeda) Kriebel, 2016

Kriebel, Ricardo, 2016, A Monograph of Conostegia (Melastomataceae, Miconieae), PhytoKeys 67, pp. 1-326 : 162-165

Conostegia dissitiflora (Almeda) Kriebel comb. nov. Fig. 149

Conostegia dissitiflora (Almeda) Kriebel. Basionym: Miconia dissitiflora Almeda, Proc. Calif. Acad. Sci, series 4, 46(5): 146, f. 5. 1989. Type: Costa Rica. Puntarenas: above Golfito along road to television tower, elev. 50-500 m, 16 Jul 1977, F. Almeda, Wilbur, R. and T. Daniel 3093 (holotype: CAS!, isotypes: BM, BR, CR!, DUKE, F!, MO!, NY!, US!).

Description.

Sparingly branched shrub 1-3 m tall with terete and glabrous internodes; the distal branches moderately to sparingly stellate-furfuraceous; the nodal line present. Leaves of a pair somewhat unequal in size, sessile and clasping or with petioles 1-9 mm long. Leaf blade 4-22 × 1.3-10 cm, 5-7 plinerved, with the innermost pair of veins diverging 0.4-3.5 cm above the blade base in sub opposite or alternate fashion, elliptic to elliptic ovate, the base rounded to subcordate and sometimes oblique, the apex acuminate, the margin undulate-dentate to subentire, adaxially glabrous, abaxially glabrous or with some stellate hairs on the elevated primary veins. Inflorescence a terminal, erect or reflexed divaricately branched, paniculiform dichasium, 6.4-20.5 cm long, branching at or above the base, accessory branches absent, branches glabrescent, thin and wiry, bracteoles paired, sessile and fused into a short nodal collar forming an elevated internode ridge, 0.5 mm long, lance triangular to subulate, persistent. Pedicels 1.5-2.5 mm long. Flowers 5 merous, calyx in bud not calyptrate but closed in bud and crowned by an apiculum, rupturing irregularly at anthesis into 2-5 hyaline lobes 1-1.5 mm long. Flower buds 1.75-2.25 × 1.5-1.75 mm, hypanthium 1.5-1.85 × 1.5-1.65 mm, campanulate, glabrous to stellate puberulent, calyx tube ca. 0.5 mm long, the calyx teeth subulate, 0.5 mm long. Petals 3.25-3.75 × 1.5-2 mm, translucent white, oblong-lanceolate, reflexed at anthesis, the apex acute to retuse, glabrous. Stamens 10, alternately unequal with the larger stamens inserted on the torus opposite the petals and the small ones opposite the calyx lobes, radially arranged around the style, the filaments 1.5-2 mm, with a geniculation near the apex, white, anthers 1.5-2 × 0.5 mm, linear-oblong, yellow, laterally compressed, the pore 0.15 mm, somewhat dorsally inclined. Ovary 5-locular, inferior, minutely puberulent at the apex. Style 2.5-3 mm, straight, vertical distance from the anther to the stigma 1.25-1.5 mm, horizontal distance absent, stigma truncate, 0.3-0.5 mm wide. Berry 3-4 × 3-4 mm, purple black. Seeds 0.36-0.7 mm, mostly ovoid, with densely muricate or verrucose testa.

Distribution

(Fig. 150 ). Endemic to south Pacific Costa Rica, mainly in the Golfo Dulce region and the Osa Peninsula but also towards to mountains on the road from San Vito de Coto Brus to Ciudad Neily, from sea level to 660 m elevation.

Conostegia dissitiflora is a distinctive species on the basis of its overall glabrous, plinerved, sessile leaves, and 5-merous flowers with an irregularly rupturing calyx. Almeda (1989a) discussed an unusual feature of this species which is the presence of “anisomorphic” stamens, with the larger set of stamens positioned opposite the petals. The three flowering populations observed had flowers with exserted styles as is common in section Geniculatae . Interestingly, when Almeda (1989a) described this species, he compared it to Conostegia cinnamomea which it falls very close to in the molecular phylogeny. The two share almost complete glabrosity and plinerved venation. Almeda (1989a) discussed similar problems in placing Conostegia dissitiflora in Cogniaux’s sections as he encountered placing Conostegia calocoma . The problems arose because staminal characters including anther shape and lack of stamen appendages suggested section Amblyarrhena , but a fused calyx suggested section Laceraria .

Specimens examined.

COSTA RICA. Puntarenas: Sierpe, Reserva Forestal Golfo Dulce, Rincón, cerca de la desembocadura del Río Rincón, Aguilar 11413 (NY); R. F. Golfo Dulce, Península de Osa, Río Tigre, Quebrada Pizote, Azofeifa 783 (INB, NY); R. F. Golfo Dulce, Península de Osa, Puerto Jiménez, Río Nuevo, Kriebel et al. 5070 (INB, NY); Península de Osa, Guadalupe La Tarde, Kriebel et al. 5378 (INB).

Figures

Figure 149. Conostegia dissitiflora. A Habit B Leaf adaxial surface C Close up of a flower D Berry. Photos of A and C of specimen vouchered R. Kriebel 5070, and B, D vouchered R. Kriebel 5378.

Figure 150. Distribution of Conostegia dissitiflora.