Albizia saman is known under a wide range of common names, such Saman, Rain Tree or Monkey Pod (see also below). It is often placed in the genus Samanea, which by yet other authors is subsumed in Albizia entirely. This legume tree is native to the mainland neotropics, from Mexico south to Peru and Brazil, but has been widely introduced to the Pacific islands, including Hawaii. Saman is a wide-canopied tree with a large symmetrical crown. It usually reaches a height of 25 meters and a diameter of 40 meters. The leaves fold in rainy weather and in the evening, hence the name Rain Tree and '5 o'clock Tree' (Pukul Lima) in Malay. Several lineages of this tree are available e.g. with reddish pink and creamish golden colored flowers.
During his 1799-1804 travels in the Americas, Alexander von Humboldt encountered a giant Saman tree near Maracay (Venezuela). He measured the circumference of the parasol-shaped crown at 576 ft (about 180.8 m), its diameter at around 190 ft (about 59.6 m), on a trunk at 9 ft (about 2.8 m) in diameter and reaching just 60 ft (nearly 19 m) in height. Humboldt mentioned that the tree was reported to have changed little since the Spanish colonization of Venezuela; he estimated the Saman to be as old as the famous Canary Islands Dragon Tree (Dracaena draco) of Icod de los Vinos on Tenerife.
The tree, called Samán del Guère (transcribed Zamang del Guayre by von Humboldt) still stands today and is a Venezuelan national treasure. Just like the dragon tree on Tenerife, the age of the Saman in Venezuela is rather indeterminate. As von Humboldt's report makes clear, according to local tradition it would be older than 500 years today, which is rather outstanding by the genus' standards. It is certain however than the tree is quite more than 200 years old today. But it is one exceptional individual; even the well-learned von Humboldt could not believe it was actually the same species as the Saman trees he knew from the greenhouses at Schönbrunn Castle.
The name Rain Tree was coined in tropical India, especially Bengal. Its origin is the moisture that collects on the ground under the tree, largely the honeydew-like discharge of cicadas feeding on the leaves.
In the Caribbean region it is occasionally called marsave. As an introduced plant on Fiji, it is called vaivai (ni vavalagi), from vaivai "watery" (in allusion to the tree's "rain") + vavalagi "foreign".