The status of Cecropia (Urticaceae) introductions in Malesia: addressing the confusion

As part of the great global movement of plants in the 18th and 19th centuries, many valuable and commercial plants were sent from the Neotropics to Europe as seeds or as live specimens. Cecropia (Urticaceae) was in cultivation in England in 1789, yet species delimitation was not well-understood until much later, long after subsequent introductions to other tropical regions where alien populations are now invasive. The earliest record of Cecropia being cultivated in Malesia is based on material of C. peltata thought to have been sent from the Royal Botanic Gardens Kew to ’s Lands Plantentuin (Buitenzorg) in Jawa, Indonesia, sometime between 1862 and early 1868. In 1902, C. peltata was first cultivated in the botanical gardens of Singapore and introduced to Peninsular Malaysia in 1954. The source of these latter introductions is uncertain. Many researchers have assumed that C. peltata is the only species of Cecropia introduced in Indonesia, Malaysia and Singapore. We confirm that C. peltata is naturalised in Singapore and is invasive on the island of Jawa, Indonesia, and in Peninsular Malaysia. However, a second introduced species, C. pachystachya, has also been discovered as invasive in both Jawa and Singapore. There is no evidence for the third previously introduced species, C. palmata, being extant in Malesia.