Kalmar “pteridosperm” kalma ce ta kimiyya wacce ke nufin wani nau’in tsiron tsohuwar iri da ta rayu a zamanin Carboniferous da Permian, wanda ya wanzu kimanin shekaru miliyan 299 zuwa 252 da suka wuce. Kalmar “pteridosperm” ta fito ne daga kalmomin Helenanci guda biyu: “pteridion,” wanda ke nufin fern, da “sperma,” wanda ke nufin iri. Pteridosperms an siffanta su da ganye kamar fern da sifofin haifuwa masu ɗauke da iri, kuma sun kasance mambobi masu mahimmanci na farkon dazuzzuka waɗanda suka rufe duniya a wannan lokacin.