1	"Perennial rhizomatous herbs; fruits lacking acute projections"	"Triglochin striata"
1	"Annual herbs; fruits with projections"	2
2	"Basal leaf-sheath distally extended to form a short ligule; inflorescence made up of 2 solitary sessile female flowers and one stalked spike of bisexual flowers arising from axil of each basal leaf-sheath; style short in bisexual flower, long and thread-like in female flower"	"Triglochin scilloides"
2	"Basal leaf-sheath without a ligule; inflorescence many-flowered, racemose or spike-like; flowers all bisexual; style short"	3
3	"Fruit projections basal or distal, c. 1–1.5 mm long; fruit 1–2.5 mm wide"	4
3	"Fruit projections up to 0.5 mm long, basal or as lateral wings; fruit 0.4–1.2 mm wide"	6
4	"Carpels 3, all fertile; fruit 6-sided, subcylindric basally (slightly broader at base), abruptly conical distally"	"Triglochin turrifera"
4	"Carpels 6, 3 fertile alternating with 3 sterile; fruit inverted-pyramidal or narrowly pyramidal"	5
5	"Fruit narrowly pyramidal; fertile carpels basally with 2 lateral recurved spurs c. 1–1.5 mm long, often with 2 small deflexed spurs connected by a membrane between the larger recurved spurs"	"Triglochin isingiana"
5	"Fruit inverted-pyramidal, distally with spreading points c. 1 mm long"	"Triglochin mucronata"
6	"Fruits angular-oblong, fertile carpels distally and basally with 4 lateral wings, such that each carpel appears 6-angled when viewed dorsally"	"Triglochin hexagona"
6	"Fruits narrowly pyramidal to suboblong, rarely ovoid; fertile carpels basally with 2 lateral acute or obtuse points, rarely also with 2 minute downward points"	7
7	"Fruit broadly ovoid, more than 0.6 mm wide; fertile carpels with 2 lateral points and 2 minute downward points"	"Triglochin trichophora"
7	"Fruits narrowly pyramidal to suboblong, less than 0.6 mm wide, if more than 0.6 mm wide, pyramidal, never ovoid; fertile carpels with 2 lateral points"	8
8	"Fruits less than 2.2 mm long, sessile, pedicle less than 0.2 mm long"	"Triglochin minutissima"
8	"Fruits  (2.2–)3.2–5.8 mm long, subsessile, pedicle usually more than 0.2 mm long"	9
9	"Fruit narrowly pyramidal, convex dorsally, more than 0.5 mm wide; fertile carpels with basal lateral points 0.1–0.5 mm long"	"Triglochin nana"
9	"Fruit narrowly cylindric, flattened dorsally, c. 0.5 mm wide; fertile carpels with basal lateral points up to c. 0.1 mm long"	"Triglochin longicarpa"