Flora of North America species comparison

radially symmetric, underground (rhizomatous) and aerial, not readily fragmenting, irregularly forked;

both rhizomatous and aerial stems often with 1 branch arrested, budlike, tips straight; rhizomatous stems hard to distinguish on wholly creeping plants;

aerial stems erect or ascending, sometimes decumbent to slightly creeping, budlike arrested branches restricted mostly near stem base.

not readily fragmenting, prostrate, upperside and underside structurally different, irregularly forked, branches determinate, tips upturned in extremely dry conditions.

dimorphic, not clearly ranked.

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

abaxial ridges present;

apex with transparent to opaque, flattened bristle 0.1–0.3 mm, sometimes becoming acute (by breaking off of bristle).

solitary, 0.5–2.5(–3.5) cm;

sporophylls lanceolate, strongly tapering toward tip, abaxial ridges prominent, base glabrous, margins short-ciliate, apex long-bristled.

solitary, 5–10 mm;

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

borne on upperside of stems, restricted to lower stems or throughout stem length, 0.3–0.5 mm diam.

borne on upperside of stem throughout, 0.25–0.3 mm diam.

stem leaves persistent or deciduous, tightly appressed, scalelike.

stem leaves appressed, ascending, green, linear-lanceolate, 3–4.7 × 0.45–0.65 mm;

abaxial ridges present;

base abruptly adnate, rounded, pubescent;

margins long-ciliate, cilia white to whitish, spreading, 0.1–0.2 mm;

apex not keeled to slightly keeled;

bristle white to whitish or yellowish to greenish near base, puberulent, 0.65–1.85 mm (1/3–1/2 length of leaves).

leaves lanceolate, 2–2.5 × 0.5–0.6 mm;

base decurrent, glabrous;

margins ciliate, cilia transparent to opaque, spreading or ascending, 0.06–0.13 mm.

leaves linear-lanceolate to slightly falcate (on marginal ranks), 1.9–2.25 × 0.4–0.55 mm;

base abruptly adnate, pubescent or glabrous;

margins ciliate, cilia transparent to opaque, spreading, 0.06–0.15 mm.