Reassessment of the taxonomic status of Cyperaceae on Rapa Iti, Austral Islands, French Polynesia, with a new combination, Morelotia involuta

<p>We reassess the current taxonomic status and distribution of Cyperaceae on Rapa Iti, Austral Islands, French Polynesia. This includes the poorly known <i>Machaerina involuta</i> H.St John (Cyperaceae, tribe Schoeneae), 86 years after it was first collected. Detailed morphological examination revealed that <i>M. involuta</i> belongs in <i>Morelotia</i> Gaudich., and the new combination, <i>Morelotia involuta</i> (H.St John) J.J.Bruhl & R.L.Barrett, is made here. Nineteen species of Cyperaceae are reported for Rapa Iti (10% of the vascular flora). The high diversity of Cyperaceae invites further discussion of the biogeographic connections and environmental conditions of Rapa Iti and a summary is provided. Notes on additional Cyperaceae named from Rapa Iti (<i>Carex rapaensis</i> (H.St John) K.L.Wilson, <i>Carex stokesii</i> F.Br., <i>C. stokesii</i> var. <i>aristata</i> F.Br., <i>Cyperus rapensis</i> F.Br., <i>Eleocharis caribaea</i> var. <i>stokesii</i> F.Br., <i>Gahnia stokesii</i> F.Br. and <i>Rhynchospora stokesii</i> F.Br.) are presented and a presently unidentified Carex is noted.</p>