Pteridium esculentum (Forster, 1786) Cockayne, 1908

Schwartsburd, Pedro B., Yañez, Agustina & Prado, Jefferson, 2018, Formal recognition of six subordinate taxa within the South American bracken fern, Pteridium esculentum (P. esculentum subsp. arachnoideum s. l. - Dennstaedtiaceae), based on morphology and geography, Phytotaxa 333 (1), pp. 22-40 : 27

Key to subspecies of Pteridium esculentum in South America

1. Laminar tissue between the veins abaxially glabrous and visible, without farinaceous appearance ................................................... ................................................................................................................................................... P. esculentum subsp. arachnoideum

-. Laminar tissue between the veins abaxially fully covered by gnarled hairs and not visible, with farinaceous appearance..............2

2. Ultimate segments without free lobes between them (a few decurrent lobes may be present); simple distal segments to 1(–1.5) cm long................................................................................................................................................... P. esculentum subsp. campestre

-. Ultimate segments with free lobes between them; simple distal segments to 2.5(–4) cm long.........................................................3

3. Veins abaxially with sericeous appearance, with lax, arachnoid hairs, 0.6–0.8 mm long, or sometimes glabrescent to glabrous ...... ............................................................................................................................................................. P. esculentum subsp. gryphus

-. Veins abaxially with strigose appearance, with stiff, acicular hairs, 0.2–0.3 mm long........................................................................ ........................................................................................... P. esculentum subsp. arachnoideum × P. esculentum subsp. campestre