Sori are covered by thin, fragile indusia and occur near the midvein of fertile pinnules. The closest relative of A. alpicola is thought to be Alsophila polycarpa, which differs by lacking spines altogether.
The sori on *A. alpicola* are covered by thin, delicate indusia and are found near the midvein of fertile pinnules. The closest relative of this species is *Alsophila polycarpa*, but it lacks spines.