ABSTRACT A taxonomic synopsis of Cypella (Iridaceae) in Brazil is presented with recognition of 16 species, two of them represented by two subspecies. An identification key to the taxa is provided and species are described and illustrated. New synonyms are indicated, and eight lectotypes, two epitypes and one neotype are designated. Results include distribution, habitat, phenology, conservation status, notes and examined specimens of all taxa, as well as comments on dubious and misused names. The resulting framework revealed that most of the Brazilian species of Cypella occur in the state of Rio Grande do Sul and in the Pampa Biome, although Río de la Plata grasslands (RPG) is the most species-rich biogeographic unit of the genus.

Abstract Sisyrinchium is the largest genus of Iridaceae in the Americas and has the greatest amount of cytological data available. This study aimed at investigating how genomes evolved in this genus. Chromosome number, genome size and altitude from species of sect. Viperella were analyzed in a phylogenetic context. Meiotic and pollen analyses were performed to assess reproductive success of natural populations, especially from those polyploid taxa. Character optimizations revealed that the common ancestor of sect. Viperella was probably diploid (2n = 2x =18) with two subsequent polyplodization events. Total DNA content (2C) varied considerably across the phylogeny with larger genomes detected mainly in polyploid species. Altitude also varied across the phylogeny, however no significant relationship was found between DNA content changes and altitude in our data set. All taxa presented regular meiosis and pollen viability (> 87%), except for S. sp. nov. aff. alatum (22.70%), suggesting a recent hybrid origin. Chromosome number is mostly constant within this section and polyploidy is the only source of modification. Although 2C varied considerably among the 20 taxa investigated, the diversity observed cannot be attributed only to polyploidy events because large variations of DNA content were also observed among diploids.