Flora of North America species comparison

gray, fissured.

gray, cracked and fissured.

alternate or whorled, rigid, angle of divergence about 45°.

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

pale green, becoming yellow with age, not viscid, glaucous, with numerous longitudinal grooves;

internodes 1–6 cm.

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

internodes 1–5 cm.

opposite (rarely in whorls of 3), 2–4(–8) mm, connate to 1/2–3/4 their length;

bases thickened, brown, completely deciduous;

apex obtuse.

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–several at node, ellipsoid, 4–8 mm, sessile or on short peduncles with 2 pairs of basal bracts;

bracts opposite, 5–9 pairs, yellow to light brown, obovate, 3–4 × 2–3 mm, membranous;

bracteoles slightly exceeding bracts;

sporangiophores 3–5 mm, exserted to 1/4–1/2 their length, with 6–9 sessile to short-stalked (less than 1 mm) 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–several at node, nearly globose, 5–11 mm, on long peduncles, with 1–2 pairs of basal bracts;

bracts opposite, 3–5 pairs, nearly circular, 4–8 × 3–6 mm, herbaceous, with light brown to yellow-green center, occasionally pinkish tinged, margins entire.

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, 1–3 mm, apex obtuse.

buds conic, 1–3 mm, apex obtuse.

= 14, 28.