Chamaecrista glandulosa var. mirabilis (Leguminoceae: Cesalpinoidea) is an endemic and endangered plant species of Puerto Rico. The last population of this species is established at the “Reserva Natural Laguna Tortuguero”, a subtropical, moist forest in the northern limestone belt in Puerto Rico. This study focuses on the phenology, pollination and reproductive success, which has been identified as key abiotic factors in management and conservation of this federal listed species. The pattern of flowering and fruit production was studied. Floral visitors were identified, and important abiotic factors were recorded using a climatological station (HOBO microstation). Peak production of buds, flowers and fruits were found between the months of December to February (2016-2017), following seasonal patterns of rain and drought. The soil composition of this habitat consists mostly of silica sands which is low in nutrients. We analyzed the pollen morphology using scanning electron microscopy (SEM) to determine the potentials pollinators and mating system
Results/Conclusions
Four potential pollinators were identified, and some behave as buzz pollinators that generate vibrations at different frequencies to obtain pollen from poricidial anthers. Individual flowers were most frequently visited, during hours in the morning, by hymenopterans. The plant has a poor percent of reproductive success, nevertheless, aborted seeds have been found, and spaces without seeds in the fruit were also identified implying that there are unfertilized ovules and a high activity of herbivory of seeds. Chamaecrista glandulosa var mirabilis is at high risk of further population reduction, favoring inbreeding due to a lack of pollination limitation, seed predation, anthropogenic influence, natural habitat disturbances, that conducive to fragmentation and loss of habitat.