5 research outputs found
Usefulness of morphological characters for infrageneric classification of Elatostema (Urticaceae)
In 1896, Hans Hallier was the first author to reduce the two genera Pellionia and Procris to subgeneric status within the genus Elatostema (Urticaceae). In 1935 and 1936, Hilde Schröter and Hubert Winkler proposed the following four subgenera: subg. Elatostema, subg. Elatostematoides, subg. Pellionia and subg. Weddellia, while maintaining Procris as a distinct genus. More recently, Wang (1980a) rejected Schröter and Winkler’s subgeneric classification of Elatostema and proposed a sectional and serial infrageneric classification of recognising as sections Androsyce, Elatostema, Laevisperma, Pellionioides and Weddellia (as ‘Weddelia’). He maintained both Pellionia and Procris as distinct genera. All previous researchers of Elatostema and related taxa primarily based their classifications on the morphology of leaves, stipules, inflorescence and receptacle. Our analysis, based on similar morphological characters, does not support the previous infrageneric classifications. Procris forms a monophyletic clade, nested within a clade consisting of several species of Elatostema subg. Pellionia and one of subg. Elatostematoides. Elatostema auriculatifolium (subgeneric classification unclear) is also included within this clade. This clade is sister to the E. latifolium–E. tsoongii pair of species (also subg. Pellionia), subg. Elatostema (the remaining species of this subgenus), species of subg. Weddellia and E. rostratum (subg. Elatostematoides).
Elatostema subg. Weddellia is paraphyletic within subg. Elatostema. The recognition of Elatostematoides, Pellionia and Procris as distinct genera is not supported
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
What is in a name? That which we call cecropia peltata by any other name would be as invasive?
The recent opinion piece by Sheil and Padmanaba (2011) argues that greater attention is required for invasive species management procedures that are relevant to and realistic for developing countries. They use the example of the Neotropical tree Cecropia as an introduction to West Java to illustrate their point. In our invited response we contend that the assumptions and data on the dynamics of Cecropia in Java presented in their paper, as well as their review of global Cecropia introductions, are of reduced scientific value. Even so, we agree with the paper's opinion that the naturalised species of Cecropia in West Java represent a considerable invasion risk and that funding must be improved so that the capacity for invasion ecology research and management of invasive alien species in developing countries is more effective. Unlike Sheil and Padmanaba (2011), however, we conclude that there is already enough evidence to be concerned by the threat of Cecropia to natural ecosystems, but that knowledge of the relevant taxa is currently insufficient to recommend the most appropriate control options not only for Java, but also for other Cecropia introductions elsewhere in the world. © 2011 CSIRO Ecosystem Sciences