Flora of North America species comparison

gray, fissured.

gray, cracked and irregularly fissured.

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

alternate 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, then gray with age, glaucous, with numerous very fine longitudinal grooves;

internodes 3–10 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.

in whorls of 3, 5–15 mm, connate to 1/2–3/4 their length;

bases becoming gray and shredded with age;

apex spinose.

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.

1–several at node, obovoid, 6–10 mm, on short, scaly peduncles;

bracts in 8–12 whorls of 3, reddish brown, obovate, slightly clawed, 3–4 × 2–3 mm, membranous;

bracteoles nearly equaling bracts;

sporangiophores 4–5 mm, exserted to 1/4 their length, with 4–5 short-stalked 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 1–several at node, obovoid, 10–15 mm, on short, scaly peduncles (rarely sessile);

bracts in 6–9 whorls of 3, circular, 8–12 × 8–12 mm, papery, translucent with reddish brown center and base, base clawed, margins entire.

buds conic, 1–3 mm, apex obtuse.

buds spinelike, to 10 mm.

= 14, 28.