Morphological diversity of Chara oedophylla Feldmann and description of C. acortiphylla S.D. Muller & A. Daoud-Bouattour, sp. nov., a new related taxon from Tunisia

Chara oedophylla Feldmann, previously known to exist in only a few sites around the Mediterranean and in southern Russia, has been identified in 17 new localities in Tunisia. Plants from 13 of these new populations and from four co-occurring populations of Chara vulgaris L. were collected and used for a detailed morphological study so as to define the diagnostic characteristics of C. oedophylla with respect to C. vulgaris. We also discovered a different plant form in southern Tunisia displaying the characteristic gametangia of C. oedophylla but with ecorticated branchlets. We describe that plant as C. acortiphylla S.D. Muller & A. Daoud-Bouattour, sp. nov.