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, 7–15 × 3–9 mm;

teeth 10–32, articulate and usually shed early, leaving dark rim on sheath.

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

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

vallecular canals nearly as large.

lasting less than a year, occasionally overwintering in the southwestern United States, usually unbranched, 20–150 cm;

lines of stomates single;

ridges 10–32.

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 rounded to apiculate with blunt tip;

spores green, spheric.

=216.

=216.