Nature's candy

Natural History, Nov, 2001 by Kirsten L. Weir

Flowering plants have evolved many clever ways to get themselves pollinated; one of the best is to compensate pollinators with tasty treats. Among plants pollinated by birds, such rewards usually are given in the form of liquid nectar. Now Marlies Sazima, of the Universidade Estradual de Campinas in Brazil, and colleagues have discovered a novel plant prize: candy pellets.

The researchers studied Cumbretum lanceolatum, a shrub that grows along muddy riverbanks and ponds in western Brazil's Pantanal floodplain. They found that each of the shrub's flowers produces a single clear jellylike pellet, formed when the plant's inner wall swells and gelatinizes as it comes in contact with nectar. Oozing out of the flower's center, this mixture solidifies into a sweet gumdrop. Unlike liquid nectar, these floral confections aren't renewed after they've been eaten.

Over a total of eighty-seven hours, team members recorded twenty-eight species of birds, from eight families--most often parakeets, macaws, kiskadees, tanagers, and finches--dining on the sweets. Perched on the shrubs to collect the pellets, the birds often brushed against the showy greenish flowers, dusting their throats and breasts with pollen. Thanks to this reproduction strategy, the plant is spreading rapidly. ("The Sweet Jelly of Combretum lanceolatum Flowers [Combretaceae]: A Cornucopia Resource for Bird Pollinators in the Pantanal, Western Brazil," Plant Systematics and Evolution 227, 2001)