The flowers that give us chocolate are ridiculously hard to pollinate
A complicated reproductive system makes pollination a tough job
By Susan Milius
It’s a wonder we have chocolate at all. Talk about persnickety, difficult flowers.
Arguably some of the most important seeds on the planet — they give us candy bars and hot cocoa, after all — come from pods created by dime-sized flowers on cacao trees. Yet those flowers make pollination just barely possible.
Growers of commercial fruit crops expect 50 to 60 percent of flowers to make a fruit, or pod, says Emily Kearney of the University of California, Berkeley. In some places, cacao crops manage to be that prolific. But worldwide norms run closer to 15 to 30 percent. In the traditional Ecuadorian plantings that Kearney studies, cacao achieves a mere 3 to 5 percent pollination.
The first sight of a blooming cacao tree (Theobroma cacao) can be “disconcerting,” Kearney says. That’s because most flowers come directly out of the trunk, rather than sprouting from branches as in many other trees. For cacao, special trunk pads burst into little pale constellations of five-pointed starry blossoms. Some trunks, says Kearney, “are completely covered with flowers.”