Sp. Pl. 1: 338. 1753; Gen. Pl. ed. 5; 157, 1754.

Common names: Arrow-grass troscart
Etymology: Greek, treis, three, and glochis, a point
Treatment appears in FNA Volume 22.

Herbs, perennial. Roots occasionally with tubers. Rhizomes stout. Leaves erect, terete; sheath with ligule apically entire or 2-lobed. Inflorescences spikelike racemes, scapose; scapes shorter than to longer than leaves. Flowers bisexual, of 1 type, short-pedicellate; tepals 6, in 2 series, distinct, yellow-green, conchiform; stamens 4 or 6; anthers nearly sessile; pistils 6, 3 fertile, 3 sterile or 6 fertile, separating when mature; ovules 1 per locule; styles absent. Fruits schizocarps, globose to linear in fruit; mericarps 3 or 6. x = 6.


Nearly all temperate areas, reaching tropics, especially in higher elevations.


The fruit type of Triglochin has been variously denominated interpreted. We follow R. M. T. Dahlgren et al. (1985), who considered the fruits to be schizocarps with 1-seeded mericarps.

Although Linnaeus, in his original publication of the name, treated Triglochin as neuter, botanical tradition in North America and elsewhere has generally assigned feminine gender (ICBN International Code of Botanical Nomenlature, Art. 62.1); for this reason and because the Greek word gGlochin (g l w c i n ) is feminine (ICBN, Art. 62.2), the feminine gender is the more correct under the Code and is adopted in the Flora. The use of the neuter gender in some recent works appears to reflect a pre-1987 wording of the Code that was held to require adoption of the gender assigned by the original author.

Species ca. 12 (4 in the flora).


1 Fertile pistils 6; fruiting receptacle without wings; ligule apically 2-lobed. > 2
1 Fertile pistils 3; fruiting receptacle with wings; ligule apically entire. > 3
2 Leaves typically shorter than scape, slender to thickish, erect from sheath; racemes 6–45 cm Triglochin maritima
2 Leaves usually equaling scape, very slender, curving outward from sheath at 30–50° angle; racemes 2–7 cm Triglochin gaspensis
3 Schizocarps linear; mericarps weakly ridged, more than 5 mm Triglochin palustris
3 Schizocarps globose; mericarps strongly 3-keeled, less than 2 mm Triglochin striata