Group of N. concentrica growing on log. Photo by Jason Carley.
Commonly known as one of the tank bromeliads, Neoregelia concentrica
is an epiphyte that is native to Brazil. It has become a common plant for collectors, and over 200 hybrids have been created that have varying leaf color and patterns. The leaves of N. concentrica
grow very close to each other and at slight angles. This creates a depression or tank in which water can accumulate and is called a phytotelma. This is of obvious importance to N. concentrica
itself as this is a major source of water for this epiphyte. What is more intriguing, however, is how important this trait is to the greater community.
Close-up of phytotelma. Photo courtesy of Botanischen Garten zu Berlin.
Growing in the jungles of Brazil, N. concentrica
and other closely related bromeliads, are home to a surprising diversity of creatures. To begin with, algae colonize the water-filled tanks and help support the plant by providing it with nitrogen and other nutrients created by the algae or left by the deceased. These algae in turn become food for the larvae of mosquitoes that lay their eggs in these well-protected tanks. Although they are well-protected, invertebrates such as frogs and lizards can find these tanks and eat the mosquito larvae and often lay their eggs in the tanks as well. In this way, the seemingly small and insignificant pool of N. concentrica
becomes a microcosm that supports a large number of species. N. concentrica
is not without benefit though; the wastes of all of these organisms become food for the plant and is one of the ways that N. concentrica
can grow into very large colonies without ever putting roots into the ground.
 Brouard O, A-H. Le Jeune, C. Leroy, R. Cereghino, O. Roux, et al. (2011) Are Algae Relevant to the Detritus-Based Food Web in Tank-Bromeliads? PLoS ONE 6(5): e20129. doi:10.1371/journal.pone.0020129
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