Article

Two records of the polymorphic taxon Anthemis cretica L. (Asteraceae) on serpentine outcrops in central Tuscany are reported. The species is new to this region, and the two isolated populations mark the northwestern distribution limit of the taxon. Based on morphology of mainly capitula and achenes, the populations can be referred to A. cretica subsp. columnae (Ten.) Franzén, and karyological analyses showed that these are tetraploid with x = 9. Populations are located in garrigue-like communities of the association Armerio-Alyssetum bertolonii, together with several obligate serpentine endemics. At these sites A. cretica is found at only ca. 300 and 500 m a.s.l., well below its normal altitudinal range which is usually above 1200 m. Such findings reveal the capacity of this species to penetrate into mediterranean habitats and to tolerate the several anomalies of the ultramaphic substrates, as confirmed by its presence in similar habitats of Greece and, probably, Albania.