Apocynaceae of Oman: Orbea nardii, sp. nov. and Pentatropis bentii, first finding

Summary Orbea nardii, a new species found in the mountains of Al Mughsayl (central Dhofar, Oman) is here described and compared with some other closely related species of Orbea. Moreover the presence of Orbea luntii in Dhofar is confirmed on the basis of its finding on the southern slope of Jabal Samham and, finally Pentatropis bentti, found in the mountains of Hasik, eastern Dhofar, is recorded for the first time.