Conostegia brenesii Standl.

Kriebel, Ricardo, 2016, A Monograph of Conostegia (Melastomataceae, Miconieae), PhytoKeys 67, pp. 1-326 : 54-57

Conostegia brenesii Standl. Fig. 71

Conostegia brenesii Standl., Field Mus. Publ. Bot. 18: 801. 1938. Type: Costa Rica. Alajuela: La Palma de San Ramón, 1275-1300 m, 7 August 1927, A. Brenes 5577 (holotype: F!, isotypes: CR!, NY!). Note: at least one sheet bearing this number (also at NY) is of Conostegia montana (Sw) Don ex DC. Schnell (1996).

Description.

Shrubs to small trees 1.5-4 m tall with tetragonal young stems that soon become terete and which are densely covered with stipitate-stellate trichomes; the nodal line inconspicuous to absent. Leaves of a pair equal to somewhat unequal in length. Petioles 0.6-4.9 cm. Leaf blades 5-13.2 × 2.5-6.5 cm, 5 nerved or more commonly slightly plinerved, with the innermost pair of veins arising up to 1.5 cm above the base in opposite to sub opposite fashion, elliptic to elliptic-ovate, the base acute or obtuse, the apex acute and acuminate, the margin denticulate or entire, densely hirsute with rigid hairs on both surfaces. Inflorescence a terminal panicle 4.8-9.6 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 absent, the rachis greenish-purple to purple, densely covered with stipitate stellate trichomes, the bracts absent or very early deciduous, bracteoles 1-4 mm, deciduous. Flowers 5-6 merous, calyptrate, flower buds 5.2-7.51 × 2.4-4 mm, rounded at the base, acute apically, the calycine and hypanthium portions weekly differentiated, slightly constricted at the torus; hypanthium 3-3.5 × 2.75-3.25 mm, covered with stipitate-stellate trichomes. Petals 5-6.5 × 6-6.25 mm, pink, light violet or white, obovate, spreading, rounded and emarginate, glabrous. Stamens 11-15, 6.25-7.25 mm, slightly zygomorphic, forming a 45 degree angle, the filament 3.75-4.25 mm, not evidently geniculate, white, anthers 2.5-3 × 0.5-1 mm, linear-oblong and somewhat recurved, laterally compressed, the base sagittate, yellow, the pore 0.1-0.2 mm, terminal. Ovary 6 (-7)-locular, inferior, glabrous and elevated into a collar around the base of the style. Style 5.5-6.5 mm, bending below the stigma, distance between the anther and the stigma -0.1 - -0.3 mm, horizontal distance absent; stigma subcapitate, 1.4-1.6 mm wide. Almost mature berry 5-6 × 5-6, probably purple at maturity like its close relatives. Seeds 0.4-0.6 mm, pyramidal, smooth.

Distribution

(Fig. 72 ). Endemic to cloud forests on the Caribbean slope of the Central and Tilaran cordilleras in Costa Rica, 1100-1750 m in elevation.

Conostegia brenesii is a very distinctive and narrow endemic of middle elevation cloud forests in Costa Rica. It can be easily distinguished by its dense indument of stipitate stellate hairs on all plant parts. Because of its dense indument of stipitate stel late hairs it is similar to Conostegia caelestis which is allopatric occurring in northern Central America. In addition, Conostegia brenesii tends to be a shrubby species whereas Conostegia caelestis tends to be a larger tree. The flowering time differs with Conostegia caelestis flowering in the first half of the year and Conostegia brenesii flowering in the second half of the year consistently from July to September. The molecular phylogeny does not place these species as sister taxa, which suggests convergent evolution in the dense stipitate stellate indument (Fig. 1 ). Conostegia brenesii falls sister to the Conostegia montana - Conostegia setosa complex in the molecular phylogeny.

Specimens examined.

COSTA RICA. Alajuela: Zapote, San Carlos, Caribe watershed, Smith 1102 (NY); La Palma de San Ramón, Brenes 5633 (CR, NY); San Carlos, P. N. Juan Castro Blanco, entrando por San Vicente faldas del Cerro Platanar, Rodríguez et al. 6050 (INB, NY); Vara Blanca de Sarapiqui , north slope of the Central Cordillera , Skutch 3161 (NY); Forests of La Palma , Tonduz 12580 (NY) . Puntarenas: R. B. Monteverde, Haber 352 (CR) . San José: Cuenca del Sarapiqui , Braulio Carrillo, cerca de el túnel, Kriebel 4907, 5631 (INB) .

Figures

Figure 1. Infrageneric classification in Conostegia next to the recently generated molecular phylogenetic hypothesis of Conostegia. Colors show the classification proposed by Schnell (1996). To the right of the phylogeny is the sectional classification proposed here. The phylogeny is a slightly modified version of the majority rule consensus tree derived from a Bayesian analysis of DNA sequences from four chloroplast regions and two nuclear ribosomal spacers (Kriebel et al. 2015) pruned to one accession per species.

Figure 71. Conostegia brenesii. A Branch with inflorescence B Leaf abaxial surface C Inflorescence D Flower at anthesis E Longitudinal section of flower bud F Pickled flower at anthesis G Pickled flower at anthesis with half of the petals and stamens removed H Petal I Stamen J Style K Longitudinal section of the hypanthium. Photos of specimen vouchered R. Kriebel 5631.

Figure 72. Distribution of Conostegia brenesii.