Sceptridium rugulosum is a fern in the family Ophioglossaceae.
Sceptridium rugulosum resembles S. dissectum (dissected grapefern) and S. multifidum (leathery grapefern), with which it commonly grows; however, its leaf emerges from the ground in late May, before the former and after the latter. The sterile deltoid-shaped leaf blade averages 4-8 cm (1.6-3.1 in.) long, with the petiole more or less the same length (shorter in sun forms and longer in shade forms). Unlike the rounded lobes.. more