The paper discusses the notion of morphological complexity, with a focus on stem patterns. Stem patterns, creating stem-based inflectional classes, are morphological constructs which come about as a result of observing the patterns rendered by the stem-form alternations (or stem splits (Baerman/Corbett forthcoming)), which one extracts after the formation of word-forms within paradigms. Stem-based inflectional class formation constitutes one aspect in the analysis of non-canonical paradigms, which also include affix-based inflectional classes, syncretism, defectiveness, and overabundance Corbett 2005, 2007, 2009; Baerman, Brown and Corbett 2005; Thornton 2010). While these non-canonical instances are in themselves interesting to observe, it...