"Alnus rugosa" shine sunan kimiyya ga nau'in bishiyar da aka fi sani da "speckled alder" ko "tag alder". Itace bishiya ce wacce ta fito daga Arewacin Amurka, ana samunta a wuraren dausayi kamar fadama, marshes, da bankunan rafi. Bawon bishiyar yana da launin toka-launin ruwan kasa kuma an yi masa alama da farin lentil, yayin da ganyen ke da duhu kore kuma yana da ɗan ɓalle. Itacen yana samar da ƙananan 'ya'yan itace kamar mazugi waɗanda suke da itace kuma suna kan bishiyar a duk lokacin hunturu.