Aspectos de la biología floral y visitantes de Streptosolen jamesonii (Benth) Miers (Solanaceae)

Spa: Se estudiaron algunos aspectos de la biología floral y visitantes florales de Streptosolen jamesonii (Benth) Miers, un arbusto comúnmente llamado mermelada con usos ornamentales que se distribuye desde Bolivia hasta Costa Rica y que en Colombia se encuentra en los departamentos de Antioquia, Boyacá, Cundinamarca, Putumayo y Quindío. El trabajo se realizó en inmediaciones del campus de la sede Central de UPTC en diferentes flores de seis individuos. Se estableció el sistema sexual de la planta y de la flor, período de antesis de la flor con y sin visitantes florales, las señales de advertimiento y recursos florales, así como sincronía entre la receptividad estigmática y la disponibilidad de polen. Se realizaron medidas morfométricas de corola, altura de estambres y pistilo; semidió el volumen y concentración de azúcares en el néctar con ayuda de un refractómetro de mano y microcapilares calibrados de 10 μl

Do distylous syntopic plant species partition their floral morphological traits?

Morphological niche partitioning between related syntopic plants that are distylous (with short- and long-styled morphs) is complex. Owing to differences in the heights of stigmas and anthers, each floral morph must place pollen onto two distinct parts of the body of the pollinator. This led us to hypothesize that such partitioning should be more accurate among distylous syntopic species in comparison to combinations with other related plants that do not co-occur. We tested these assumptions using a set of Palicourea (Rubiaceae) species as a model system. We compared the distribution, flowering phenology, floral measurements and reciprocity of sexual organ heights of two syntopic species (Palicourea rigida and Palicourea coriacea) and one non-syntopic congener (Palicourea marcgravii). The three species overlapped in their distributions and flowering periods. The position of sexual organs was, in most cases, partitioned between syntopic populations, with low overlap in anther and stigma heights. However, we found a higher overlap involving the non-syntopic species, especially between Palicourea rigida and Palicourea marcgravii. Additionally, reciprocity of sexual organs was more accurate in intraspecific inter-morph combinations (i.e. legitimate organ correspondence) in comparison to intraspecific intra-morph, interspecific syntopic and interspecific non-syntopic combinations. The partitioning of morphological traits between syntopic species might facilitate the differential placement of pollen on the body of the pollinator and reduce the chances of interspecific interference