The morphology and distribution of Convolvulus acanthocladus and its allies are reviewed. The group consists of C. acanthocladus, C. argyracanthus, C. iranicus and C. spinosus and a new species, C. hormodensis Ranjbar & Ezazi (Convolvulaceae), from Hormozgan province, southern Iran, which is described and illustrated. The paper highlights the macro- and micro-morphological differences between the five species and shows the value of trichome characters in distinguishing between species. The paper is illustrated with tables and photographs.
