Abstract
Contribution to the vascular flora of Pietraporciana Nature Reserve (southern Tuscany, Italy). With the aim of improving the available botanical knowledge of Southern Tuscany and of the Pietraporciana Reserve, located in the south-eastern part of Siena province, the Tuscan Section of the Società Botanica Italiana (S.B.I.) organized a field excursion to prepare a contribution to the vascular flora. In this report we provide two separate floristic inventories of both the results of recent ield survey data and a literature search. The lists include respectively 372 and 123 specific and subspecific taxa. Species of interest for the region include: Crataegus xmedia (first record for Tuscany), Teucrium siculum subsp. siculum (very rare in Southern Tuscany), Avena sterilis subsp. ludoviciana (second record of this subspecies for Tuscany), and Centaurea arrigonii (first record for Southern Tuscany). Eleven Italian endemic taxa were recorded at the Reserve. Thirtysix are the species of conservation interest, 24 of which included in Tuscany Regional Law 56/2000. Only two exotic species (Artemisia verlotiorum and Robinia pseudoacacia) were recorded as self-introduced at the reserve. This study highlights peculiarities of the flora present including species typical of xerophilous grasslands and more orophilous species.