Eriocaulon benedictum and E. naviculum (Eriocaulaceae): Two New Species from the Brazilian Cerrado

Abstract

Abstract— Two new species of Eriocaulon (Eriocaulaceae) from the Brazilian Cerrado are described and illustrated. Eriocaulon benedictum, found in the Tocantins River Basin and Plate River Basin has a vegetative morphology similar to Eriocaulon aquatile and E. modestum due to the submerged life form with submerged leaves and long scapes surpassing the water column, but differs from both by the presence of a submerged stem with spiral leaves (vs. a rhizome with rosulate leaves), obtrullate floral bracts (vs. oblong floral bracts in E. aquatile or obovate in E. modestum), and band shaped projections on the seeds (vs. post shaped projections on E. modestum or projections absent in E. aquatile). Eriocaulon naviculum, found in the Araguaia River Basin, an emergent species, has a floral morphology similar to E. altogibbosum and E. gibbosum due to the presence of gibbous sepals in the pistillate flowers, but differs from both by the grey trichomes on the leaf sheath (vs. translucent trichomes in the latter species), slightly sinuous scapes (vs. straight scapes in the latter species), membranous, gibbous swelling in the sepals of the pistillate flowers (vs. incrassate gibbous swelling in the latter species), and seeds without projections with a rough lumen (vs. seeds without projections with a smooth lumen in E. gibbosum or seeds with band-like projections in E. altogibbosum). Detailed descriptions, including anatomical and seed data, illustrations, and maps of occurrence are presented for the new species, as are data on the ecology, geographic distribution, and risk assessments. An updated key for Eriocaulon species from the Tocantins-Araguaia River Basin is also provided.