Flora of North America species comparison

somewhat elongate, 3–5 × 2–4 mm;

teeth 8–18, narrow, 1.5–4 mm, centers dark and margins white.

green with black apical band, spreading, 1–6 × 1–5 mm;

teeth 3–14, not articulate.

dimorphic;

vegetative stems green, branched, 16–50 cm;

hollow center 1/6–1/3 stem diam.

persisting more than a year, unbranched, 6–55 cm;

lines of stomates single;

ridges 3–12.

brown, with stomates, initially unbranched, persisting and becoming branched and green after spore discharge.

in regular whorls, horizontal to drooping, solid;

ridges 3;

valleys channeled; 1st internode of each branch equal to or longer than subtending stem sheath;

sheath teeth deltate.

apex pointed;

spores green, spheric.

=216.