Cauliflory: Flowers that Bloom on Tree Trunks

One of the most striking botanical sights in a tropical forest is a tree trunk covered with flowers or fruit. Even a single flower will stand out on a stark wooden trunk. Cauliflory is a condition found in trees and woody vines where flowers and fruit are borne directly on the trunks and older branches. Many different plant families are known for cauliflory. While rare in temperate climes, it is common in tropical forests among the occasional emergent or canopy tree but most often found on understorey trees. Animals that benefit from cauliflory are terrestrial frugivorous vertebrates and bats. In Malaysia and Borneo cauliflorous trees are not an uncommon sight when trekking through the forest.

Many familar species of trees have cauliflorous fruit, from the edible fruit of the Papaya, Carica papaya, to the giant fruit of the Jackfruit, Artocarpus heterophyllus and the very useful New World tropical tree, the Calabash, Crescentia cujete.

Cauliflory is interpreted as a strategy for plant species to offer their flowers and fruits to understory pollinators and fruit (seed) dispersers. Ficus may be one of the most speciose genera in any lowland tropical forest and is sometimes referred to as a "keystone" species because many vertebrates rely on figs when there is no other, or very little food available. In Lambir Hills National Park, Sarawak 77 species and 6 varities of Ficus have been recorded. This very large genus of plants presents it fruit in many different ways with many species being cauliflorous.

The gallery on this site shows photos of many different species of cauliflorous trees that I have come upon in my travels throughout Malaysia and Borneo.

Jeff Shimonski