SEM images of the microspore of Isoetes ulei (Ule 3533, HBG), I. martii (Regnel 1505, B) and I. × goebelii (Pereira 718, UPCB). A–C Microspore of I. ulei A Proximal view B Distal view C Equatorial view D–F Microspore of I. martii D Proximal view E Equatorial view F Distal view G–I Microspore of I. × goebelii G Proximal view H Equatorial view I Equatorial view. All scale bars = 2 µm