Plants with strands of old leaves at base, (5--)10--15(--20) cm. Leaves curving outward from sheath at 30--50° angle, slender, almost terete, equaling or slightly longer than scapes, (5--)10--15(--20) cm; sheath 12.5--21  1.8----3 mm, ligule often hoodlike, apically 2-lobed; blade 0.5--1 mm wide, apex acute. Inflorescences: scapes often purple near base, (5--)10--15(--20) cm  0.5--1(--1.5) mm; thick; racemes (2--)3--5(--7) cm; pedicels 1.4--4  0.1 mm. Flowers: tepals somewhat rounded, 1.2--1.5  1.1--1.8 mm, apex obtuse; pistils (3--)6--(9--12), 6 fertile. Fruits: fruiting receptacle without wings; schizocarps linear, 3--4  1 mm; mericarps linear, weakly ridged, 3--4  1 mm, beak recurved, 0.9--1 mm. 2n = 96.

Flowering summer (Jul--Aug). Tidal saltwater marshes, usually submerged daily; of conservation concern; 0 m; N.B., Nfld. and Labr. (Nfld.), N.S., P.E.I., Que.; Maine.

Plants of Triglochin gaspensis tend to form lawnlike patches in contrast to the clumped habit of other northern species of the genus.