Key to Wisconsin Aspleniaceae

Author: Robert F. Freckmann

• 1a.Blades simple (rarely with a basal lobe separated as a pinna), long-tapering to a slender tip; margins entire to deeply lobed 2

• 1b.Blades compound with several separate pinnae, or rarely with many deep lobes slightly connected by soft tissue; apex of blades not forming a long slender tip 3

• 2a.Margins entire or shallowly undulate; blade tips often rooting, producing new plantlets; veinlets rejoining to form a network A. rhizophyllum

• 2b.Margins deeply lobed; tip not rooting and forming plantlets; veinlets free at tips A. pinnatifidum

• 3a.Blades 2 --3 times compound, with 2--5 widely-spaced pairs of irregular pinnae, deeply-lobed or divided into spatulate pinnules toothed at apex A. ruta-muria

• 3b.Blades once compound with many closely-spaced pairs of regular oblong pinnae, not divided into pinnules 4

• 4a.Fertile leaves erect, usually more than 20 cm tall, much longer than the spreading sterile leaves; pinnae with broad overlapping basal lobes projecting upward along the rachis; largest pinnae more than 8 mm long A. platyneuron

• 4b.Fertile and sterile leaves similar, usually less than 20 cm tall; pinnae narrowed at base, not lobed or overlapping, less than 8 mm long 5

• 5a.Petiole and rachis dark red-brown to black A. trichomanes

• 5b.Upper part of petiole and rachis green to light tan A. viride