Although we visited the Cerrado in the dry season, there were many shrubs and trees putting out new leaves and flowers, even in the absence of any trace of rainfall for the past 6 months. Extensive underground aquifers that fill during the rainy season are tapped by deep roots of most of these plants, ensuring that they can flower and produce seeds when their pollinators and seed dispersers are present.
One of these small shrub/trees was quite common, and was particularly noticeable because of its huge displays of large, white flowers.
This is the Pequi tree, (Caryocar brasiliense), whose large white flowers produce copious nectar and pollen. It blooms only during the dry season — July to September.
The leaves of Pequi trees are leathery, an adaptation to living in an arid environment. The flowers are rather large (bee in the top flower provides size comparison) and white with lots of yellow stamens. They produce copious nectar throughout the night, which is higher in sugar concentration in the morning than the evening.
Artistic view of the Pequi flowerhead
If there were a single plant species whose absence would markedly affect insect, bird, mammal, even human populations in the Cerrado, the Pequi would be it.
Pollination is done mainly by bats at night, but the plant is also visited by nocturnal moths, wasps, and ants, all feeding on the nectar produced by the flowers. In the daytime, no nectar is produced, but bees and wasps visit the flowers to feed on pollen.
Hummingbirds may be found on the flowers at dusk and in early morning, cashing in on that last sweetened formula of nectar the flowers put out. Guira, White-lined, Palm, and Siaca Tanagers along with Curl-crested Jays also frequent the flowers at dusk as well:
Colorful Guira Tanagers sip the nectar, eat the flowers, and munch on the seeds of the Pequi. Photo by Dario Sanches.
Curl-crested Jays hang around the Pequi trees in the very early morning hours, perhaps to feast on the insects that are attracted to the flowers. (Photo by Debbie Reynolds)
Glittering bellied Emerald hummingbirds are one of many hummingbird species that depend heavily on the nectar provided by flowering trees.
But that’s not the only role that Pequi plays in the Cerrado. Well-pollinated flowers produce a bounty of nuts, eaten by animals and especially favored by indigenous people of the Cerrado.
Pequi seeds in Cuiaba, Brazil market (Photo by Mateus Hidalgo).
The pulp surrounding the seeds has been described as aromatic, fruity, and cheesy, and can be eaten raw or used to flavor other dishes. The seeds (with spines removed) are roasted and eaten like peanuts, or crushed to extract their oil, so the whole fruit has great commercial value. Pequi trees are typically planted around villages for residents to harvest the tree’s bounty.