Flora of North America species comparison

to 5 pairs, strongly ascending, well separated, distance between 1st and 2d pinnae not or slightly more than between 2d and 3d pairs, basal pinna pair approximately equal in size and cutting to adjacent pair, obliquely narrowly cuneate, undivided to tip, margins sharply denticulate and often shallowly incised, apex rounded, venation like ribs of fan, midrib absent.

to 5(–9) pairs, spreading, usually remote, separated 1–3 times pinna width, in some populations irregularly and extensively fused with considerable webbing along rachis, distance between 1st and 2d pinnae not or slightly more than between 2d and 3d pairs, basal pinna pair approximately equal in size and cutting to the adjacent pair, mostly linear to linear-spatulate, undivided to tip, margins crenulate to dentate, usually notched or cleft into 2 or several segments, apex rounded to acute, venation like ribs of fan, midrib absent.

stalk 3–10 mm, 1/6 length of trophophore rachis;

blade yellow-green, oblong to oblong-lanceolate, 1-pinnate, to 6 × 1.5 cm, thin but firm.

stalk usually absent but sometimes broadly tapered to 10 mm in forms with coalesced proximal pinnae;

blade glaucescent, oblong, longitudinally folded when alive, 1-pinnate, to 4 × 1.3 cm, very fleshy.

2-pinnate at base of sporangial cluster, 1.3–2 times length of trophophore.

1(–2, rarely)-pinnate, 1–1.5 times length of trophophore.

=180.

=90.