Morphological features characterize variations in morphological form which are independent of syntactic context. They contrast with morphosyntactic features, which characterize variations in form correlated with different syntactic contexts. Morphological features account for formal variation across lexemes (inflectional class), as well as morphosyntactically incoherent alternations within the paradigm of a single lexeme. Such morphological features are not available to the syntax, as is made explicit in the principle of 'morphology-free syntax'. Building on work on stress patterns in Network Morphology and on stems in Paradigm Function Morphology, we take initial steps towards a typology of these morphological features. We identify four types: inflectional class features (affixal and prosodic), stem indexing features, syncretic index features and morphophonological features. Then we offer a first list of criteria for distinguishing them from morphosyntactic features (independently of the principle of morphology-free syntax). Finally we review the arguments demonstrating the need to recognize morphological features. © Springer Science+Business Media B.V. 2007