Testing Trees from around the World

KKL-JNF's 50 acre Gilat tree nursery in the south is a testing ground for trees from all over the world to see which species are suitable for growing in Israel.

The Silk Floss Tree from Paraguay

Scientific (Latin) name: Chorisa speciosa
Common name: Silk Floss tree
Countries of origin: Paraguay, Argentina, Brazil
Aliya to Israel: About 23 years ago


A split open fruit releases kapok fibres. Photo: Tania Susskind

Anyone walking through Tiberius cannot fail to notice the rounded silk floss trees with their unique green trunk that line the city's main street. Chorisa speciosa, commonly known as the silk floss tree, is considered one of the most beautiful trees in the world and grows in the jungles of Paraguay and northern Argentina.  When in full bloom, clouds of large, flimsy lily-like pink flowers cascade from its green branches. Another one of the tree's distinctive features is the wicked-looking array of stout spines that crowd around the trunk, which can protrude by a number of centimeters near the base. The green trunks allow the tree to photosynthesize when leaves are absent, and the spikes prevent animals from eating it.

The silk floss tree is a rounded, briefly deciduous tree that sheds its leaves during dry seasons in order to conserve moisture. It can grow rapidly the first few years and then slow considerably. Once established, it is pest resistive and drought tolerant. The inedible fruit has the general appearance of large green-colored avocados with the texture of a juicy cucumber.  When mature, the fruit splits open, releasing masses of white silky kapok-like material that is used primarily as fillers for mattresses, pillows, upholstery, softballs and life preservers. A kapok-filled life jacket can support 30 times its own weight in water.


Photo: Tania Susskind

Silk floss trees were one of the first species to be planted at KKL-JNF's Gilat tree nursery. Due to its sharp thorns, it is not exactly a tree one would like to hug, but it is very popular in city parks and other public spaces thanks to its singular beauty. The tree, which can grow to more than 15 meters high with an equal spread, creates a play between shadow and light that is beautiful to behold.

It is not invasive but can form large surface roots at the base of the trunk, so be careful in areas with sidewalks or other pavement. This tree resists breakage and does not create litter problems once the seed pods are picked up.

The nectar of the profuse blooms of the Chorisia speciosa tree attracts insects such as monarch butterflies.
The wood of the Chorisia speciosa tree is light, soft and flexible. It is used for packaging, making canoes and making paper and ropes. Oil from the seeds is used both as edible vegetable oil and for industrial applications.
Silk floss trees are primarily used for ornamental purposes. Around the world they are planted as featured specimen trees in gardens, parks, parking lots, nature strips and along highways. The South Coast Botanic Garden near Rancho Palos Verdes is an excellent example. There picturesque pink drifts of these outstanding trees add to the tranquil garden setting.

If you have a Chorisia speciosa, prune it to be sure that only one central trunk develops when the tree is young. The central leader will become less vigorous in middle age, allowing lateral limbs to develop into the main structure of the tree, producing a spreading form.


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