Flora of North America species comparison

gray, cracked and irregularly fissured.

gray, slightly cracked and fissured.

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

alternate (rarely whorled), lax, angle of divergence about 55°.

bright green to yellow-green, becoming yellow with age, not viscid, ridges between longitudinal grooves barely papillate, smooth;

internodes 1–5 cm.

gray-green, becoming green, then yellow-green with age, glaucous, with several moderately deep longitudinal grooves;

internodes 1–8 cm.

opposite, 2–5 mm, connate to 1/2–3/4 their length, not photosynthetic;

bases thickened, brown, persistent, becoming hard, enlarged, and black;

apex setaceous.

opposite, 1–3 mm, connate to 2/3–7/8 their length;

bases splitting at margins, persistent;

apex obtuse.

2–several at node, obovoid, 5–7 mm, sessile;

bracts opposite, 6–10 pairs, light yellow and slightly reddened, ovate, 2–4 × 2–3 mm, membranous, slightly connate at base;

bracteoles slightly exceeding bracts;

sporangiophores 2–4 mm, 1/4–1/2 exserted, with 5–8 sessile to nearly sessile microsporangia.

1–2 at node, lanceoloid, 4–8 mm, sessile or on short to long, smooth peduncles;

bracts opposite, 6–12 pairs, light yellow to reddish, obovate, 2–4 × 2–3 mm, membranous, free or slightly connate at base;

bracteoles barely exceeding bracts;

sporangiophores 3–5 mm, exserted to 1/2 their length, with 4–6 long-stalked (1–2 mm) microsporangia.

cones 2–several at node, obovoid, 6–10 mm, sessile or on short, scaly peduncles;

bracts opposite, 4–8 pairs, ovate, 4–7 × 2–4 mm, membranous or papery, with yellow center and base, margins entire.

cones 1–2 at node, ovoid, 6–10 mm, on short to long, smooth peduncles;

bracts opposite, 3–6 pairs, 3–4 × 2–3 mm, ovate, connate to 1/8–7/8 their length, inner pairs becoming succulent and red when ripe.

buds conic, 1–2 mm, apex obtuse.

buds attenuate, 1–3 mm.

= 28.