Calabrese, Andrea (2012), Allomorphy in the Italian Passato Remoto: A Distributed Morphology Analysis, Language & Information Society 18. Many Italian verbs display stem alternations with highly idiosyncratic vocalic and consonantal allomorphy in the paradigm of the simple past. Due to their complexity, these alternations are often used by linguists as evidence for models assuming rote memorization of stem alternants and endings (see the recent work by Maiden 2005, 2010 for example). In this paper, I will show that these alternations are characterized by basic regularities and that a rather simple analysis of them can be formulated in the framework of Distributed Morphology (DM) (Halle and Marantz 1993; Embick 2010; Embick and Marantz 2008). In particular, this analysis involves notions such as roots, Vocabulary Items and Readjustment Rules as predicted by DM. There is no evidence for memorized stem alternants. Instead, the allomorphy we see in the Italian Passato Remoto is readily accounted for by providing an appropriate morphosyntactic analysis of the forms and by deriving the irregular alternants from single underlying roots by means of Readjustment Rules. This paper also shows that it is crucial that the rules accounting for this allomorphy obey a strict definition of locality requiring linear adjacency. This explains why the presence of the Thematic Vowel prevents their application. In the irregular forms where these rules apply, the Thematic Vowel is removed by a special pruning rule. Crucially, Impoverishment removes a diacritic index associated with the application of this pruning rule in certain morphosyntactic contexts (in the 1st and 2nd pl., and 2ndsg.), thus the regular basic form of the root will appear in these contexts. Impoverishment in this case is motivated by a general Markedness principle that disfavors complex exponence in morphologically marked environments.