Asclepias elata

This record represents Asclepias elata, following FNA (vol. 14, 2023), not including A. glaucescens, a species of Mexico and Central America. In contrast, Kartesz (1994) recognized A. glaucescens in a broad sense including A. elata. FNA (vol. 14, 2023) states "A. elata has been inconsistently recognized as distinct from A. glaucescens since the time of A. Gray et al. [1878–1897, vol. 2(1)]. However, at least since J.N. Rose (1892), the distinction between these species has been understood, and was presented clearly by R.E. Woodson Jr. (1954). Although indistinguishable in the absence of flowers, A. elata differs by fully pendent (versus erect to pendent) flowers, fewer flowers per umbel, longer corolla lobes, and corona segments that spread away from the gynostegium and are exceeded by the style apex, with the appendage merely a crest included in the segment (versus segments that are strict, overtop the style apex, and bear exserted appendages in A. glaucescens). Both species have extensive distributions, but they are largely allopatric, except in Mesoamerica. The northernmost populations of A. glaucescens are in Nayarit and San Luis Potosí. A. elata is one of a cohort of spec­ies reaching their northwestern limits in Arizona."