Bienertia sinuspersici (Chenopodiaceae):: A new species from southwest Asia and discovery of a third terrestrial C4 plant without Kranz anatomy

Our studies on the enigmatic genus Bienertia (Chenopodiaceae), with its C, photosynthesis and lack of Kranz anatomy, led us to the discovery of a second species of this previously-supposed monotypic genus. The new species is named Bienertia sinuspersici after its main range around the Persian Gulf countries and the northern side of the Gulf of Oman. Bienertia sinuspersici occurs in hot climates and is a vicariant of Bienertia cycloptera, which is found at higher latitudes and elevations in temperate and cold deserts of the region. Like Bienertia cycloptera, the new species has unique chlorenchyma cells with dimorphic chloroplasts and single cell C, photosynthesis. However, it differs anatomically by having mostly one to two layers of chlorenchyma cells, versus two to three layers in Bienertia cycloptera. Furthermore, the new species has longer cotyledon leaves, larger seeds, larger flowers, and larger chromosomes, and differs in a set of micro-morphological features. All of this supports our conclusion that this widely distributed, novel plant is an overlooked new species. Bienertia sinuspersici grows well in very hot climates, under conditions which most species can barely tolerate. Its wide distribution indicates that its novel C, photosynthesis may confer advantages for CO, fixation in these habitats not found in C, species having conventional Kranz anatomy.