Taisha is again the author of today’s BPotD entry. She also organized this entry with Thiago S. Coser, of the Museu Nacional, Universidade Federal do Rio de Janeiro, in Brazil, who shared his photographs. Taisha writes:
The bromeliad Alcantarea galactea is a newly-described species from a small area of Brazil. Thiago Coser and his co-authors gave this species its name galactea due both to its visibility from great distances and to the meaning of the Greek word gala (“milky”) in reference to its whitish colour. Because of the large size of the plants and the distinguishing colour (a result of a thick layer of epicuticular wax upon the leaves and bracts), populations of the plants can even be seen from aerial photographs of the area via Google Earth.
Plants of Alcantarea galactea form an infundibuliform (or funnel-shaped) rosette of leaves. They spread vegetatively by basal shoots. The yellow flowers are borne on lateral peduncles arranged distichously on a suberect or slightly pendulous inflorescence branch that is covered in bracts. The stamens are spread like that of another species from the genus, Alcanterea extensa, suggesting plants are pollinated at least partly by bats. Alcantarea galactea shows some similarities to other species within the genus, particularly Alcantarea odorata and Alcantarea patriae. However, the other related species are geographically isolated, and they differ in habit size, colour, inflorescence shape and size, bract morphology, and stamen organization.
Alcantarea galactea is the second largest of the approximately 30 or so other species within the genus, all of which are endemic to Brazil. Alcantarea galactea is rupicolous, meaning it grows amongst rocks. This species is found at elevations of 300-650m, under full sun on inselbergs of gneiss-granite. Presently, the hundreds of individuals within the population are known to grow only in the Alfredo Chaves municipality, an area that has been altered for coffee plantations, pastures, and granite extraction mining. Because of the decrease in forested area, the population of floral visitors acting as pollinators for Alcantarea galactea may be compromised. As such, this species may be considered an endangered species according to the IUCN in association with the restricted area of occurrence, small population size, and potential decline in suitable habitat.
To read the paper, see: Coser, T. S., Versieux, L. M., Wendt, T. 2013. Alcantarea galactea (Bromeliaceae), a giant Bromeliad from Brazil, with populations seen from the sky. Systematic Botany. 38(2): 339-343.