Flora of North America species comparison

gray, slightly cracked and irregularly fissured.

gray, cracked and fissured.

alternate or whorled, rigid, angle of divergence about 60°.

opposite or whorled, rigid, angle of divergence about 30°.

gray-green, becoming gray with age, glaucous, slightly scabrous, with numerous very fine longitudinal grooves;

internodes 2–6 cm.

pale green, becoming yellow with age, not viscid, usually smooth or very slightly scabrous, with numerous longitudinal grooves;

internodes 1–5 cm.

in whorls of 3, 2–6 mm, connate to 2/3–3/4 their length;

bases splitting at margins, persistent, forming black, thickened collar;

apex acute.

opposite, 1–3 mm, connate to 1/2–3/4 their length;

bases membranous, brown, shredding and becoming gray with age, ± persistent;

apex obtuse.

1–3 at node, narrowly ellipsoid, 5–8 mm, on very short, scaly peduncles (rarely sessile);

bracts in 6–9 whorls of 3, light yellow, ovate, 3–4 × 2–3 mm, membranous, base short-clawed;

bracteoles equaling bracts;

sporangiophores 3–5 mm, exserted to 1/3 their length, with 3–7 sessile to short-stalked microsporangia.

2–several at node, ellipsoid to obovoid, 4–8 mm, sessile;

bracts opposite, 4–8 pairs, light yellow, obovate, 2–3 × 2 mm, membranous, slightly connate at base;

bracteoles exceeding bracts;

sporangiophores 3–9 mm, 1/4–3/4 exserted, with 6–10 sessile to short-stalked (less than 1 mm) microsporangia.

cones 1–3 at node, lance-obovoid, 8–15 mm, on short, scaly peduncles (rarely sessile);

bracts in 6–9 whorls of 3, obovate, 4–8 × 3–5 mm, papery, yellow-translucent with green-yellow center and base, base broadly clawed, margins slightly dentate.

cones 2–several at node, obovoid to ellipsoid, 6–13 mm, sessile or on short peduncles;

bracts opposite, 4–7 pairs, elliptic, 3–7 × 2–4 mm, membranous with light brown to green, thickened center and base, slightly connate at base, margins entire.

buds conic, 1–4 mm, apex acute.

buds conic, 1–3 mm, apex obtuse.