Ricardo Kriebel

Discovery of unusual anatomical and continuous characters in the evolutionary history of Conostegia (Miconieae: Melastomataceae).

Conostegia has been traditionally defined to consist of 42 species in the tribe Miconieae. Recent phylogenetic studies have cast doubt on the monophyly of the genus and highlighted the need for a phylogenetic study focused on Conostegia. The purpose of this study was to test the monophyly of Conostegia and address relationships in the genus. We addressed the evolutionary history of Conostegia using DNA sequences from six loci. Difficulty in finding discrete characters that support clades prompted an anatomical survey of leaves and flowers as well as the exploratory use of some continuous characters. We coded as many species as possible for fifteen characters. Lastly, field work was conducted to document floral traits at anthesis due to the poor quality of preservation of flowers on herbarium specimens. Conostegia was found to be paraphyletic and composed of three main clades. The historically important characters of a calyptrate calyx and pleiostemony were found to have evolved more than once inside the Conostegia clade. Several other characters were found to support the clades we identified. The most unusual characters were mucilage inside the ovary which is here reported in the Melastomataceae for the first time, a stele inside the style which is mostly restricted to one clade of Conostegia and known only in this clade of the Melastomataceae, and herkogamy which has been lost in two clades within Conostegia. A combination of molecular phylogenetic analyses and broad morphological surveys allowed the better understanding of the evolutionary history in a clade of mostly cloud forest Neotropical trees. The need to include anatomical studies and tackle continuous characters is here demonstrated.

CliNAl vARiATioN ANd The deCouPliNg oF vegeTATive ANd RePRoduCTive ChARACTeRs iN AcisAntherA seCTioN AcisAntherA (MelAsToMATACeAe)

Abstract n Clinal variation in morphology from north to south and to a lesser degree from east to west is described in the widespread Neotropical species of Acisanthera sect. Acisanthera. While northernmost and southernmost species are separable from one another, they are bridged by other species which results in a complicated morphological continuum. Two important characters were detected in the data that correlate with geographic distribution: first, flowers on compound inflorescences in plants south of Amazonia and with solitary flowers north of Amazonia; and second, anther pore width from narrow (0.2 mm) in South America to wide (0.38 mm) mainly in Central America and the Caribbean. A high degree of plasticity in the first character south of Amazonia (inflorescence structure) complicates differential diagnosis between species in the southern end of their distribution. Adding leaf shape and indument helps differentiate the currently recognized species although in some cases with difficulty. These cases are discussed particularly in reference to Acisanthera variabilis. Although most continuously varying vegetative characters are positively correlated with geography, two floral characters are not (anther pore width and anther appendage connective length) which suggests differing selection pressures. Overall, partitioning of vegetative from reproductive characters indicates they are uncoupled, a result which supports Bergs correlation-pleiades hypothesis.

A synopsis of the genus Poteranthera (Melastomeae: Melastomataceae) with the description of a new, apparently pollinator deceiving species

A synopsis of the annual genus Poteranthera is presented here. Three species are recognized including the newly described Poteranthera windischii. Poteranthera is characterized by its annual life cycle, generally linear leaves that have conspicuous gland-tipped hairs on the lamina margin, 5-merous flowers with a constriction at the level of the torus, one cycle of stamens reduced to staminodia or absent altogether, three locular ovary, and reniform seeds with a foveolate testa. The flowers of the new species P. windischii are strongly heterandrous, where the usual set of stamens that bees harvest pollen from is reduced to staminodia and the stamen set that deposits pollen on the bee has large yellow ventral appendages that possibly function as pollen mimics and result in deceit pollination. This hypothesis is supported by experiments that have demonstrated innate preferences of female bees for yellow, UV absorbing colors in flowers. Species of Poteranthera are extremely rare, known from very few specimens and possibly highly endangered.

A new species of Blakea (Melastomataceae) from Panama with foliaceous sepal appendages and zygomorphic flowers

The new species Blakea bocatorena is described from Bocas del Toro province in Panama. It is only the third species to be described in the genus that has foliaceous appendages on the sepals. The other two species with these sepal appendages are B. calycosa and B. tuberculata. Blakea bocatorena differs from the latter two species in that it has white petals and a type of herkogamy in which the style is opposite the stamens and results in a zygomorphic flower. In B. calycosa and B. tuberculata, the larger petals are pink-magenta and tuberculate with the stamens encircling the exserted style resulting in a radially symmetric herkogamous flower.

Three new species in the neotropical genus Clidemia (Melastomataceae: Miconieae)

We here propose and describe three new species of Clidemia: C. aguilarii from Costa Rica and Panama; C. aurantiaca from Costa Rica, Panama, and Ecuador; and C. subpeltata, a Costa Rican endemic. Phenological notes, distribution maps, line drawings, color images of the live plants in the wild, and discussions comparing the new species to their presumed closest relatives are provided.ResumenAquí proponemos y describimos tres especies nuevas de Clidemia: C. aguilarii de Costa Rica y Panamá; C. aurantiaca de Costa Rica, Panamá, y Ecuador; y C. subpeltata, endémica de Costa Rica. Se incluyen notas sobre su fenología, mapas de su distribución, ilustraciones, fotografías a color de plantas silvestres, así como discusiones comparando las nuevas especies con sus parientes aparentemente más cercanos.

Five New Species of Miconia (Melastomataceae: Miconieae) from Costa Rica and Panama

Abstract. n We describe five new species of Miconia: M. kappellei and M. ricardoi, both endemic to the Cordillera Talamanca in Costa Rica, M. hildeana from a narrow altitudinal belt of Caribbean slope cloud forests of Costa Rica and adjacent Panama, and M. cocoensis and M. diegogomezii, both endemic to Cocos Island, Costa Rica.