Flora of North America species comparison

limp, unkeeled, flat to plano-convex, 0.2–0.8(–2.5) m × 2–5(–10) mm.

stiff, keeled from base at least to middle, flattened distally, to 1.2 m × 5–15 mm.

rachis unbranched, flexuous, its fertile part usually erect at water surface;

bracts ascending, lower bracts inflated near base; pistillate heads 2–5, at least some supra-axillary, not contiguous, sessile or most proximal peduncled (often prominently so in deeper water), 1–3 cm diam. in fruit; staminate heads (1–)2–4, contiguous and appearing as one elongate head, not contiguous with distalmost pistillate head.

rachis (0–)1–3 branched, erect, bracts strongly ascending, not basally inflated; pistillate heads (1–)2–4 on main rachis, 0(–2) on lateral branches, axillary, not contiguous, sessile or short-peduncled, 2.5–3.5 cm diam. in fruit; staminate heads 3–8 on main rachis, 1–6 on lateral rachises, most not contiguous.

tepals without subapical dark spot, erose-tipped, stigma 1, lance-ovate.

tepals often with prominent subapical dark spot, subentire to entire;

stigma 1, linear.

reddish to brownish, dull, short-stipitate, ellipsoid to fusiform, not faceted, body constricted at equator, 3–7 mm, tapering to beak;

beak straight, 1.5–2 mm;

tepals attached at base, reaching about to equator.

brown, proximally dull, distally shiny, subsessile to short-stipitate, fusiform, usually constricted near equator, body not strongly faceted, 5–7 × 2.5–3 mm, tapering to beak;

beak often curved and hooked, 4–7 mm;

tepals attached at base, reaching to equator or somewhat beyond.

1.

1.

= 30.