This paper traces the employment of original Phoenician-Punic guttural graphemes, <ˀ>, <ˁ>, , and <ḥ>, to represent vowel phonemes in later Punic. Three typologically distinct treatments are identified: 1) morphographic, where the grapheme <ˀ> indicates the etymological glottal stop /ˀ/ (its original function) as well as vowel morphemes without specifying their phonological character; 2) morpho-phonographic, where guttural graphemes continue to indicate etymological guttural consonants, but now both the presence of a vowel morpheme and (potentially) the vowel quality of that morpheme; and 3) phonographic, where the same set of guttural graphemes serve to denote vowel phonemes only, and do not any longer indicate guttural consonants. The threefold division is argued for on the basis of the Late Punic language written in Punic and Neopunic scripts. Despite the availability of dedicated vowel graphemes, these are not obligatorily written in any period of written Punic. It is suggested that a typologically significant path of development may be observed across these three uses of guttural graphemes, with 3) the endpoint of a development from morphography to phonography.