Pellaea ternifolia subsp. arizonica
Contr. Univ. Michigan Herb. 19: 42. 1993.
Petiole rounded or slightly flattened adaxially in distal portion; rachis glabrous or with a few widely scattered hairs; pinnae completely glabrous; largest ultimate segments (excluding terminal pinnae) usually more than 18 mm; spores averaging 46–53 µm diam. 2n = 116.
Phenology: Sporulating summer–fall.
Habitat: Cliffs and rocky slopes, on a variety of acidic substrates including quartzite and granite
Elevation: 1700–2400 m
Ariz., Tex., n Mexico
Pellaea ternifolia subsp. arizonica and P. wrightiana hybridize; the hybrids are morphologically intermediate tetraploids and have malformed spores.
"thick" is not a number.