Arten der Gattung Oxalis Sect. Ionoxalis in der Tschechischen Republik und in der Slowakei. 1. Oxalis latifolia

Oxalis latifolia Humb., Bonpl. et Kunth, a species native to tropical and subtropical America, was found as a noxious weed in glasshouses and hotbeds of 101 garden centres in the Czech and Slovak Republics. The first record in the Czech Republic is from Šumperk (1980), in Slovakia from Bratislava (1981). The recent distribution of the species is presented. In the glasshouses, it often persists for many years, mainly in the cultures of ornamental plants, especially Asparagus and Rhododendron simsii. In 39 localities it was found growing together with Oxalis debilis Humb., Bonpl. et Kunth. O. latifolia and O. debilis are not hardy, and do not produce seeds in central Europe. Both species reproduce by bulbils and spread with plant material and garden soil or compost. O. latifolia is specialized ephemerophyte, probably unable to become naturalized in central Europe due to climatic and biological constraints. Appropriate control measures are proposed.