Solanum elaeagnifolium and Solanum mauritianum naturalized in Taiwan
Solanum elaeagnifolium (Solanaceae, EPPO list of invasive alien plants) was recorded by Hsu and Tseng (2003) in southern Taiwan and in the Penghu Islands. Solanum mauritianum (Solanaceae) was found in Nantou County of central Taiwan and occurs in open situation. It forms a shrub or a dense tree of 2-4 m tall, branched above to form a rounded canopy, all parts are densely pubescent. Leaves are simple, alternate and elliptic, up to 30 cm long and 12 cm wide. Branched corymbs hold numerous flowers, corolla are lilac blue with a pale star-shaped area at base and are 1.5-2.5 cm in diameter. Berries are dull yellowish, they measure 1-1.5 cm in diameter and contain numerous seeds. The native range of S. mauritianum is Northern Argentina, Uruguay, Paraguay and Southern Brazil. The known introduced range of the plant is Africa (Cameroon, Comoros, Reunion, Mauritius, Madagascar, South Africa, Swaziland and Uganda), USA (California, Florida, Hawaii), India and Oceania (Australia, New Caledonia, Norfolk Island, Solomon Islands, Tonga). In Europe it is naturalized in Azores (Portugal) where it is found near villages and along water stream margins (Silva, pers. com.). The plant is considered invasive in New Zealand and South Africa. The plant seems to tolerate most soil types, but thrives in those with high water retention. The plant is also able to tolerate low temperatures and occurs in areas that are subject to light frost. The weed is both frost-tolerant and shade-tolerant to a certain degree. S. mauritianum is a coloniser of disturbed sites and can invade urban areas, native forest margins and pastoral land. All parts of the plant are poisonous to humans, especially the green berries. It has been introduced to New-Zealand as a garden plant. There are no records of the weed being spread by trade or transport, although the potential for this may well exist. The greatest risks are probably posed by deliberate introductions for ornamental or commercial purposes. Unlike S. elaeagnifolium, S. mauritianum seems too thermophile to be considered as a potential invader for the EPPO region.
Wang CM (2003) Solanum mauritianum Scop. (Solanaceae), a Newly Naturalised Plant in Taiwan. Coll. And Res. 16, 67-70.
Hsu TW, Tseng YH (2003) Solanum elaeagnifolium Cav. (Solanaceae): a noxious weeds newly naturalised to Taiwan. Endemic Species Research, 5(1), 49-51.
Global Invasive database: http://www.issg.org/database/species/ecology.asp?si=209&fr=1&sts