Conostegia brenesiana Kriebel, 2016

Kriebel, Ricardo, 2016, A Monograph of Conostegia (Melastomataceae, Miconieae), PhytoKeys 67, pp. 1-326 : 148-150

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 Ramón, 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 × 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 × 0.9-2.0 mm, the hypanthuim 1.5-2 × 1.25-1.75 mm, scurfy puberulent, calyx tube ca. 0.1 mm long, the calyx lobes depressed undulate, 0.5 × 1 mm, the calyx teeth bluntly triangular, 0.25 mm long, equaling or barely exceeding the calyx lobes. Petals 1.5-2.5 × 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 × 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 × 4.25-5.25 mm, purple black. Seeds 0.34-0.5 mm long, more or less pyramidal, frequently asymmetrical.

Distribution

(Fig. 138 ). Endemic to cloud forests in Costa Rica from 550-2100 m elevation.

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 Ramón, 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 Ramón, slope above and in the valley of the Río San Lorencito, Burger et al. 12130 (CR, MO, NY); Guatuso, P.N. Volcán Tenorio, Cuenca del Río Frío, Alto Masis, Chaves and Muñoz 361 (CR, INB, MO, NY); Estación Río San Lorenzo, Kriebel 931 (INB); Finca La Paz, San Ramón, Kriebel 1477 (INB, NY); Alfaro Ruiz, P. N. Juan Castro Blanco, Cuenca alta del Río La Vieja, Solano and Cerling 2696 (INB, NY). Cartago: Kiri Lodge, Sendero el Colibrí, Kriebel 3665 (INB, MO, NY). Guanacaste: Estación Biológica 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); Estación Pitilla, sobre la fila al Cerro Orosilito, Robles et al. 2815 (INB, MO). Heredia: Santa Bárbara, Posada Volcán Poás, Kriebel 1255 (INB, NY); Vara Blanca de Sarapiquí north slope of Central Cordillera between Poás and Barba volcanoes, Skutch 3455 (CR, NY); 9 km NO de Varablanca hacia finca Murillo, Proyecto ALAS, Solano, González and Santamaría 2134 (INB, NY). Puntarenas: Cordillera de Tilarán, San Luis, Río Veracruz, Monteverde, Fuentes 690 (CR, MO). San José: San Jerónimo de Moravia, 2 km NE del peaje, en el límite con el P. N. Braulio Carrillo, Kriebel 1113 (INB) forest near Río Hondura, Lent 1352 (CR, MO, NY); P. N. Braulio Carrillo, Faldas del cerro junto al Río Zurquí, Sector Santa Elena, Vargas and Castillo 3473 (INB, NY).

Figures

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.

Figure 138. Distribution of Conostegia brenesiana.