Abstract
Two new species of Juncus from South America are described, illustrated, and a key is provided to separate the two species from related South American species in Juncus sect. Ozophyllum. Juncus andinus is similar to J. ecuadoriensis from Venezuela, Colombia, and Ecuador, but is different in having smaller seeds and conspicuous cataphylls; it is distributed in the Andes from southern Ecuador to southern Peru. Juncus austrobrasiliensis, from Brazil, resembles J. micranthus but differs in having smaller, castaneous flower-heads and capsules with beaks that clearly protrude from the flower; it is distributed in southern Brazil from São Paulo to Santa Catarina.