Ochroma pyramidale tree, commonly known as balsa tree

The tree species Ochroma pyramidale is a flowering plant of the mallow family (Malvaceae). Its common name is Balsa tree [1-3]. Ochroma descends from the Greek meaning pale and Balsa is a Spanish word meaning raft. Other common names (Bois flot, Corkwood, Down-Tree, West Indian balsa) and binomial synonyms (Bombax pyramidal, Ochroma bicolor, O. Concolor, O. grandiflora, O. lagopus, O. obtusum) are also in use [1].

Some of the synonyms indicate the cork-like structure of the Balsa wood and its floating-on-water behavior. Natalie Angier writes that Balsa has a fifth the density of water, cork a fourth, and only the papaya-related Jacaratia has lighter wood [3].

In her interesting article, illustrated with photographs by Christian Ziegler, Angier reports that scientist have long assumed that the night-flowering tree is pollinated by bats, which are nocturnal and, many of them, nectarivores [3]. But in addition the Balsa night life attracts all kinds of species including Capuchin monkeys, olingos (distant relative of the racoon),  opossums, geckos, honeybees, hummingbirds and snakes. While the snakes are looking for prey, most of the other arboreal guests act as pollinators by drinking the syrupy juice of the mature, cream-colored balsa flowers and then carrying pollen to the female parts of another balsa tree's flower. 

Ochromas are among the fastest growing tropical forest trees thriving from southern Mexico over Panama to Bolivia [3].

References and more to explore
[1] Jungle Garden - Hardy Tropical Plants: Ochroma pyramidale: palmvrienden.net/junglegarden/not-hardy/ochroma-pyramidale/.
[2] Swartz: Ochroma pyramidale: www.cds.ed.cr/teachers/harmon/page21.html.
[3] Natalie Angier: Open all night. National Geographic May 2011, 219 (5), 130-143. [ngm.nationalgeographic.com/2011/05/panama-ochroma/angier-text].