Italian stemmer (from SnowballAnalyzer) does not work

Italian stemmer does not work.

Consider this code:

var englishAnalyzer = new SnowballAnalyzer("English");
var tk = englishAnalyzer.TokenStream("text", new StringReader("horses"));
var ta = (TermAttribute)tk.GetAttribute(typeof(TermAttribute));
tk.IncrementToken();
Console.WriteLine("English stemmer: horses -> " + ta.Term());

var italianAnalyzer = new SnowballAnalyzer("Italian");
tk = italianAnalyzer.TokenStream("text", new StringReader("abbandonata"));
ta = (TermAttribute)tk.GetAttribute(typeof(TermAttribute));
tk.IncrementToken();
Console.WriteLine("Italian stemmer: abbandonata -> " + ta.Term());

It outputs:

English stemmer: horses -> hors
Italian stemmer: abbandonata -> abbandonata

While Java Lucene 2.9.4 outputs:

English stemmer: horses -> hors
Italian stemmer: abbandonata -> abbandon