Perennial semiaquatic herb to 40 cm tall Stem: very short, hidden by the leaves. Runners spread from the plant, bearing small bulbs. Leaves: basal, wrapped in a sheath, to 30 cm long and 2 mm wide, with an unlobed sheath tip and pointed blade tip. Flowers: borne on a terminal spike-like inflorescence with a three-winged stalk. Each flower has six pale greenish yellow tepals 1 - 1.5 mm long, three egg-shaped ovaries and three stigmas. Fruit: maturing when the ovary wall splits vertically into three single-seeded sections (schizocarp), 6 - 9 mm long, linear to club-shaped, separating from the stalk from the base upward but remaining attached at the tip, each section tapering to a sharply pointed base, essentially beakless.
Similar species: The similar Triglochin maritimum does not spread by runners, is taller (to 0.8 m), has a ridged (not winged) flower stalk, and a two-lipped sheath tip. The fruit is shorter (2 - 5 mm long), egg-shaped to oblong with three to six recurved beaks, and separates into six sections.
Flowering: late June to late August
Habitat and ecology: Rare, but found locally in calcareous areas.
Occurence in the Chicago region: native
Notes: This species is less poisonous than Triglochin maritima.
Etymology: Triglochin comes from the Greek words treis, meaning three, and glochis, meaning pointed. Palustre means marsh-loving.
Author: The Morton Arboretum
From Flora of Indiana (1940) by Charles C. Deam
Very local in marly springy areas on marly shores of lakes in our northern counties and in a marly springy place in Henry County.
Very slender, 2-4 dm; lvs to 3 dm, 1-2 mm wide; raceme 1-2 dm, the very slender pedicels strictly erect; tep 6, 1-1.5 mm; stamens 6; ovaries 3, ovoid, in fr- linear-clavate, 6-9 mm, at maturity parting from the axis from the base upward, remaining attached at the summit, the base very sharply pointed; axis broadly 3-winged, the wings extending between the carpels; 2n=24. Brackish marshes along the coast, and in bogs inland; circumboreal, in Amer. s. to Pa., Ind., Io., Nebr., and N.M. May-July.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.