Polystemma cordatum (Brandegee) L.O. Alvarado Polystemma cordatum (Brandegee) L.O. Alvarado in Phytoneuron 2021-47: 12. 2021 sec. Alvarado-Cárdenas & al. 2021≡Microdactylon cordatum Brandegee in Zoë 5(11): 252–253. 1908 syn. sec. ???