Neoregelia kautskyi, Bromeliaceae
Pretty much anybody is familiar with what a pineapple fruit (Ananas comosus) looks like, and various species of Tillandsia, Bilbergia and Guzmania are now common houseplants, but there’s so much more diversity of shapes and adaptations within the Bromeliaceae to appreciate. The Neoregelia species in the photos, first scientifically described in the early ‘70s, is endemic to eastern Brasil and part of a genus of very showy and peculiar plants, commonly known as the ‘blushing bromeliads’, often hybridised to enhance their striking colour patterns. However, more than its coloration, which is probably an adaptation to attract pollinators, it’s what goes on at the center of the plant which surely catches the eye. Like many other species within the family, this Neoregelia forms a tight cup with its leaves which stores rainwater and effectively creates a miniature ecosystem. You can see the small three-petalled, tubular flowers (Bromeliads are monocots) emerging from the base of the inflorescence at the bottom of the ‘pond’ and I wish the numerous larvae wiggling and swimming around them were just as visible. If insect larvae are not that surprising to find there in the stagnant water, arboreal frogs and crabs are maybe more suggestive of the importance of the habitats these epiphytic plants create high in the canopy.
But why would a plant go through the effort of evolving in this direction when water is certainly not a limiting factor in the rainforest? Well, some bromeliads are known to show a degree of protocarnivory, which means they benefit from the nitrogen and the other nutrients dissolved in the water they collect, and these nutrients come from their animal hosts in the form of droppings and unconsumed parts of their meals, but they do not actively produce digestive enzymes to speed up the process. I actually described this fascinating concept before, when writing about wild teasel (Dipsacum fullonum), a large thistle-like plant native to Eurasia which collects rainwater in its modified sessile leaves. Protocarnivory seems to be much more diffuse in the plant world than previously believed and there is still a good deal to learn, but this just shows how evolutionary pressure plays along in ways we might not even begin to imagine until we get to understand them!