Flora of North America species comparison

short-creeping, branched, branches 1–2-forked, flat, not articulate, glabrous.

not readily fragmenting, prostrate, upperside and underside structurally different, irregularly forked;

branches determinate, tips upturned.

papery, delicate.

conspicuously dimorphic, in 8 ranks, tightly appressed, ascending, green;

abaxial ridges present;

apex with deciduous, twisted, transparent bristle ± 0.3 mm, becoming acute to slightly mucronate in oldest branches.

solitary or paired, lax, flattened, 1–4 cm;

sporophylls ovate to ovate-deltate, strongly keeled, keel dentate, base glabrous, slightly cordate to rounded, margins serrate, apex acuminate;

megasporophylls larger and wider than microsporophylls, usually on underside of strobili.

solitary, 3–8 mm;

sporophylls ovate-deltate, abaxial ridges not prominent, base glabrous, margins ciliate, apex acute to mucronate.

throughout stem length, 0.06–0.1 mm diam.

borne on upperside of stems, throughout stem length, 0.2 mm diam.

leaves nearly perpendicular to stem, green, ovate to ovate-elliptic, 1–2 × 0.5–1.3 mm;

base rounded to slightly subcordate;

margins slightly transparent, serrate;

apex acute.

leaves ovate to ovate-lanceolate or lanceolate, 1–1.8 × 0.4–0.8 mm;

base rounded to oblique;

margins green, serrate;

apex abruptly tapered, long-acuminate to bristled, frequently transparent, midrib extending into apex.

leaves lanceolate to lanceolate-elliptic (on central ranks) or falcate (on marginal ranks), 2–2.7 × 0.5–0.7 mm;

base decurrent, glabrous;

margins ciliate, cilia transparent to opaque, spreading, 0.04–0.1 mm.

leaves lanceolate, 1.3–1.4 × 0.3–0.4 mm;

base abruptly adnate, pubescent, hairs often running along groove;

margins ciliate, cilia transparent to opaque, spreading, ca. 0.1 mm.