Flora of North America species comparison

elongate, 4–9 × 2–5 mm;

teeth dark, 5–10, narrow, 2–5 mm, margins white, scarious.

green, elongate, 3.5–7.5 × 2–4 mm;

teeth 6–14, centers brown and margins white, prominent, tip usually brown, long, filiform.

monomorphic, green, branched or unbranched, 20–80 cm;

hollow center small, to 1/3 stem diam.;

vallecular canals nearly as large.

persisting less than a year or only the proximal part overwintering, unbranched, 20–60 cm;

lines of stomates single;

ridges 6–14.

when present only from midstem nodes, spreading, hollow;

ridges 4–6;

valleys rounded; 1st internode of each branch shorter than subtending stem sheath;

sheath teeth narrow.

apex pointed;

spores white, misshapen.

=216.