Résumé
Pottiaceae is a large, taxonomically difficult family with numerous xerophytic species, that is well represented in Maghreb. Sixteen taxa (Acaulon mediterraneum, A. muticum, Aschisma carniolicum, Chionoloma tenuirostre var. tenuirostre, Ephemerum crassinervium subsp. sessile, Gyroweisia reflexa, Husnotiella sinuosa, Microbryum rectum, Streblotrichum commutatum, Syntrichia caninervis var. caninervis, Tortella tortuosa, Tortula caucasica, T. truncata, T. wilsonii, Vinealobryum nicholsonii, Weissia levieri) are mentioned for the first time in Tunisia as a result of recent fieldwork, increasing the country's known number of Bryophyte species from 314 taxa to 330, and of Pottiaceae from 74 to 90 taxa (an increase of 21.6%), now close to the Pottiaceae diversity in Algeria (106) and Morocco (124). This point to the need for further bryofloristic studies in Tunisia.