Taxonomic revision and distribution of herbaceous Paramollugo (Molluginaceae) in the Eastern Hemisphere

The genus Paramollugo with the type species Paramollugo nudicaulis (≡Mollugo nudicaulis) has recently been described after molecular investigations. Here we report two new endemic Malagasy species: Paramollugo simulans and Paramollugo elliotii, and transfer a forgotten New Caledonian endemic Mollugo digyna to Paramollugo (Paramollugo digyna). Consequently, the number of Paramollugo species in the Eastern Hemisphere is increased from three to six. Almost all genus representatives (except Paramollugo nudicaulis, which has a wide distribution in Southern Asia, Arabia and tropical Africa) are endemic to Madagascar, Somalia, or New Caledonia. Since the type of seed coat ornamentation is crucial for species delimitation, a diagnostic key with new taxonomically significant carpological characters and other new traits is provided for all the herbaceous Paramollugo. The distribution patterns of Paramollugo nudicaulis s.str., Paramollugo simulans and Paramollugo elliotii are presented.