Triglochin palustris L.
Family: Juncaginaceae
Marsh Arrow-Grass
[Triglochin palustre Schousb.]
Triglochin palustris image

Plants with fibrous strands of leaves at base, 9--42.5 cm. Leaves erect from sheath, shorter than scapes, 6--24.5 cm; sheath 3.5--5 cm  1.5--5 mm, ligule not hoodlike, unlobed; blade 0.8--2.9 mm wide, apex acute. Inflorescences: scape often purple near base, mostly exceeding leaves, 5.5--27.2 cm  1--2.1 mm; racemes 5.1--21.4 cm  2--5 mm; pedicel 0.4--4.5  0.1--0.5 mm. Flowers: tepals elliptic, 1.1--1.6  0.7--0.9 mm, apex round; pistils 6, 3 fertile, 3 sterile. Fruits: fruiting receptacles with wings; schizocarps linear, 7--8.3  0.8--1.2 mm; mericarps linear, weakly ridged abaxially, 6.5--8.5  0.5--1.5 mm, beak erect, 0.3 mm. 2n = 24.

Flowering summer and early fall. Coastal and mountain marsh areas and moist alkaline meadows; 0--3700 m; Greenland; St. Pierre and Miquelon; Alta., B.C., Man., N.B., Nfld. and Labr., N.W.T., N.S., Nunavut, Ont., P.E.I., Que., Sask., Yukon; Alaska, Ariz., Calif., Colo., Idaho, Ill., Ind., Iowa, Maine, Mich., Minn., Mont., Nebr., Nev., N.H., N.Mex., N.Y., N.Dak., Ohio, Oreg., Pa., R.I., S.Dak., Utah, Wash., Wis., Wyo.; Mexico; South America; Eurasia.

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.

©The New York Botanical Garden. All rights reserved. Used by permission.

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