Common Name(s): Lebbeck, Siris Tree, East Indian Walnut, Kokko, Woman’s Tongue

Synonym(s):

Family: Fabaceae

Native To: China, Southeast Asia, and Australia

Native Habitat: Throughout the dry and moist tropics

Growth Habit: Wide spreading, fast-growing tall tree that can attain a height of over 25 meters.

Flowering: June and July

Distinguishing Characteristics: The dark green leaves over 30 cm long (12 inches) are bipinnate, with 2-4 pairs of pinnae and leaflets 2-5 cm long (1-2 inches). The pale yellow/green, Mimosa-like flowers are 2 inches in diameter and have small petals joined at the base with many showy stamens. Pods are roughly 25 cm long (9 inches), dark reddish brown, and persistent for several months. Their rattle in the breeze has resulted in a rather bizarre common name of “Woman’s Tongue”.

Natural History and Cultivation Notes: Albizia lebbeck is a common street tree in the Middle East and Northern Africa. According to the Miami-Dade (Florida) Resources Management website, it was planted along a 5-mile avenue from the Nile to the Great Pyramids to commemorate the opening of the Suez Canal in the 1880's. Plant explorer Dr. David Fairchild was enthralled by these trees and introduced them to Florida in 1899, where they quickly established.

Although in wetter climates, Albizia lebbeck is more common, even rather invasive, it is a tree that we might consider for commercial use where temperatures are mild and where drip irrigation is the more normal source of water. Apparently this species can tolerate less moisture than what we think of as tropical conditions. Purdue University’s New Crops website reports that the Siris Tree can thrive on over 5 feet of rainfall a year. Though there is no chance of that in Tucson, wide spaced drip irrigation has proven to work just fine. In addition, the tree is reported to be tolerant of alkaline soils, salinity, and salt spray with shallow roots that assist in reducing soil erosion. Although it is rated by the USDA as hardy in Zone 10a - 11, the UA trees are tougher than that. The campus trees, situated on a southern exposure near to an open basketball court, withstand winter nights into the mid 20's (F). There are no invaders anywhere on the UA campus; no seedlings popping up in cracks or alleyways. However, information from Florida indicates that sites with monsoon runoff, watercourses, and wetlands would probably encourage excessive naturalizing. In fact, in Florida it is no longer commercially propagated due to its tendency to re-seed.

The two trees on the UA campus are another legacy of Warren Jones. He remembered gathering the seeds from a cultivated tree in a small town on the Baja California peninsula, where it was valued for its shade. Now well established, the campus trees have the classic spreading shape of an open-crowned legume.

Seeds can be germinated easily if the standard hard-seeded legume scarification processes are followed. Seedlings should be encouraged to develop a broad root zone. Wide spacing of drip emitters should augment root expansion while judicious use of landscape water would restrict excessive spread.

Ethnobotany: Albizia lebbeck has dozens of uses throughout the tropical latitudes. Reforestation and firewood plantations top the list; the wood is dense and strong. In addition it is often used as the overstory tree for tea groves or coffee plantations. Bark can be used for soap and for tanning. Wood makes fine material for cabinet wood, furniture and veneer. The foliage and pods are used for fodder: Reports from the Purdue University New Crops website show high crude protein, and carbohydrates from both seeds and leaves. Folk remedies include treatments for boils, cough, eye ailments, flu, lung problems, and leprosy.

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