This handsome legume is one of the rarest plants in the world, presently known from only one mature tree in northern Guam and fewer than 120 specimens from Rota. Because of its rarity, this tree was placed on the U.S. Endangered species list in 1987. In an effort to re-establish this species, a program to propagate S. nelsonii was initiated in 1998 at the University of Guam with support from the US Air Force, the Division of Fish and Wildlife of the Guam Department of Agriculture and the the Department of Lands and Natural Resources in the Commonwealth of the Northern Mariana Islands. Staff from the Guam Division of Aquatic and Wildlife Resources, Guam National Wildlife Refuge, US Air Force, and Guam Division of Forestry erected a fence around the last remaining adult tree. The fence is designed to protect seedlings from browsing by an introduced sambar deer and feral pigs. Many of these plants have since died. The causes of death are uncertain, but the timing of one die-off coincided with a severe infestation of introduced mealybugs and the dry season.

The famous western Pacific botanist E. D. Merrill in 1919 named this species in honor of Peter Nelson of the Guam Department of Agriculture who first brought the plant to the attention of botanists. There are at least three local names: First hlyun llgu means "northern tree," perhaps in reference to its occurrence in northern Guam. Another possible gloss is "foreign tree," in possible reference to the island of Rota where this tree also occurs. The second name, more commonly used in Rota, is trongkon gulfi, meaning "fire tree," perhaps in reference to its appearance when in flower. The third name is trongkon fi'a, possibly after the Fi'a area of Rota where it is found.

Text modified from M. Marutani, P. Toves, J. Tuquero and J. Richardson. 2000. Serianthes nelsonii. Agriculture Experiment Station, Division of Agriculture and Life Sciences, University of Guam.

Photo credits: J. McConnell