Closely related to T. zollingeri, differing as follows: lamina of sterile fronds of larger plants variably ± deeply lobed, sometimes very deeply, with lamina to 30 cm long having several pairs of lobes to 14 × 3.5 cm connected by a narrow wing along the midrib, the wing decurrent below the lowest lobes; lower surface of midrib of frond, costae of lobes and main veins always bearing many short hairs; lamina of simple fertile fronds to 3 mm wide and up to 15 cm long, larger fertile fronds irregularly lobed as sterile, the lobes commonly 3 mm wide (intermediates between sterile and fertile fronds, with wider lobes, may occur).
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