The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

American bulrush, chair-maker's rush, chairmaker's clubrush, common three-square, common three-square bulrush, schoenoplectus, scirpe acere, three-square club-bulrush, western bulrush

great bulrush, scirpe des étangs, soft-stem bulrush, soft-stem club-bulrush, tule


often vertical, 1–6 mm diam., firm to hard;

scales shorter to longer than internodes, disintegrating to fibers.

3–10 mm diam.


sharply trigonous, sides convex to concave proximally, deeply concave to flat distally, 0.1–2 m × 1–6 mm, smooth.

cylindric, 0.5–3 m × 2–10 mm.



sheath fronts membranous distally, orifice adaxially truncate to concave, often splitting;

ligules 2-fid, 1 mm;

blades 2–6, proximally V-shaped, distally trigonous to asymmetrically laterally flattened in cross section, angles often scabridulous distally;

distal blade (1–)2–5 times as long as sheath, 50–750 × 2–9 mm.

3–4, basal;

sheath fronts membranous-translucent, often pinnate-fibrillose;

blades 1–2, C-shaped to dorsiventrally flat in cross section, usually much shorter than sheath, distal blade 2–200 × 1–4 mm, margins often scabridulous.



proximal bract usually erect, resembling leaf blade but trigonous proximally, (1–)3–20 cm.

2–4 times branched, branches to 15(–25) cm;

proximal bract usually erect, thickly C-shaped to subterete, 1–8 cm, margins sometimes scabridulous.


1–5(–10), 5–23 × 3–5(–7) mm;

scales bright (to very dark) orange-, red-brown, or purplish brown to straw-colored, often prominently lineolate-spotted, midrib mostly paler, ovate, 3.5–6 × 2–3 mm, smooth or awn sparsely spinulose, margins deciduously ciliolate, flanks ribless except sometimes proximal scales, midrib prominent, apex acute (to obtuse), 2-fid, notch (0.3–)0.5–1 mm deep, awn mostly irregularly bent, 0.5–1.5(–2.5) mm.

15–200, solitary or in clusters of 2–4(–7), commonly all solitary, 3–17 × 2.5–4 mm;

scales uniformly dark to pale orange-brown, sometimes straw-colored, sometimes prominently lineolate-spotted, midrib often pale or green, ovate, 2–3.5 × 1.5–2 mm, sparsely (rarely densely) reddish or straw-colored, scabrous on awn and distal parts of midrib and sometimes flanks, margins ciliate, hairs contorted;

flanks veinless, apex obtuse to rounded, notch 0.2–0.3 mm deep, awn straight or bent, 0.2–0.8 mm.


perianth members 4–8, sometimes fewer, brown, bristlelike, variably slender to stout, equal or unequal, all equaling achene body to all rudimentary, retrorsely spinulose;

anthers 2–3 mm;

styles 2–3-fid.

perianth bristles 6, brown, ± equaling achene, densely retrorsely spinulose;

anthers 2 mm;

styles 2-fid, sometimes 3-fid near spikelet apex.


brown, biconvex to compressed bluntly trigonous, obovoid to obpyriform, (2–)2.5–3.5 × 1.3–2.3 mm;

beak 0.1–0.5 mm.

dark gray-brown when ripe, plano-convex, obovoid, 1.5–2.8 × 1.2–1.7 mm;

beak 0.2–0.4 mm.


= 74, 78.

= 42.

Schoenoplectus pungens

Schoenoplectus tabernaemontani

Phenology Fruiting spring–summer (south), summer (north). Fruiting late spring–summer, spring–winter (south).
Habitat Fresh to brackish shores, marshes, lakes, fens, often emergent in water to 0.7 m Fresh to brackish marshes, fens, bogs, lakes, stream banks and bars, pioneering in disturbed places, often emergent in water to 1 m
Elevation 0–2400 m (0–7900 ft) 0–2400 m (0–7900 ft)
from FNA
AK; AL; AR; AZ; CA; CO; CT; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; SC; TX; UT; VA; VT; WA; WI; WY; AB; BC; MB; NB; NL; NS; ON; PE; QC; SK; Mexico; South America; West Indies; Europe; Australia (including Tasmania); New Zealand
[WildflowerSearch map]
[BONAP county map]
from FNA
AK; AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NL; NS; NT; ON; PE; QC; SK; YT; Mexico; Central America; West Indies; s South America; Eurasia; Africa; Pacific Islands; Australia; New Zealand
[WildflowerSearch map]
[BONAP county map]

Three varieties of Schoenoplectus pungens (under Scirpus americanus) were recognized for North America by T. Koyama (1963), and three more or less equivalent varieties were recognized by S. G. Smith (1995). These varieties are described informally and illustrated here but not formally recognized because their morphologic delimitation should be evaluated and their exact ranges are still uncertain.

Schoenoplectus pungens (Vahl) Palla var. pungens has brown to straw-colored spikelet scales, bifid styles, and lenticular achenes. It is the only variety that occurs in Europe and North America. In North America, it extends from the Atlantic Coast to Saskatoon and is reported from Arkansas, Kansas, Louisiana, Minnesota, and Missouri.

Schoenoplectus pungens (Vahl) Palla var. longispicatus (Britton) S. G. Smith has bright orange to reddish (or purplish) brown or often stramineus and lineolate-spotted spikelet scales, trifid styles, and trigonous to lenticular achenes. Endemic to the flora area, variety longispicatus occurs in western North America, except Pacific Coast, east to Saskatoon, Manitoba, and Ontario, along the north shore of Lake Superior, south to Iowa, Minnesota, western Wisconsin, Missouri, and southern Mississippi.

Schoenoplectus pungens (Vahl) Palla var. badius (J. Presl & C. Presl) S. G. Smith has uniformly dark chestnut spikelet scales, trifid styles 3-fid, and trigonous or thickly biconvex achenes. In North America, variety badius occurs along the Pacific Coast (to slightly inland) from British Columbia south to California. Outside the flora area it occurs in Baja California, Mexico, temperate South America, Australia, including Tasmania, and New Zealand.

The name Scirpus americanus [subsp. monophyllus (J. Presl & C. Presl) T. Koyama] var. monophyllus was misapplied to Schoenoplectus pungens var. badius (T. Koyama 1963). The type of the basionym Scirpus monophyllus J. Presl & C. Presl from Peru belongs to Schoenoplectus americanus (S. G. Smith 1995).

Schoenoplectus americanus, S. pungens, and S. deltarum belong to the small “Scirpus americanus complex” T. Koyama (1963), in which the species are sometimes difficult to delimit. Schoenoplectus pungens was long known incorrectly as S. americanus Persoon; the type of that name is conspecific with plants formerly treated as S. olneyi A. Gray (A. E. Schuyler 1974). Putative Schoenoplectus pungens × S. americanus hybrids [= S. ×contortus (Eames) S. G. Smith] are locally common. 2n = ca. 86–128.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Two yellow-striped forms of Schoenoplectus tabernaemontani are grown as ornamentals.

Schoenoplectus validus, described from the Caribbean, and S. tabernaemontani, described from Europe, are here treated as one variable, cosmopolitan species without infraspecific taxa, pending further studies (J. Browning et al. 1995b; S. G. Smith 1995). Most North American plants have spikelets with reddish papillae or prickles on the scales, whereas some plants of coastal and boreal North America closely resemble most plants of northwestern Europe and southern Africa in their densely reddish prickly-papillose scales and are similar to the type of Scirpus glaucus J. E. Smith.

Schoenoplectus tabernaemontani, S. acutus, S. heterochaetus, S. lacustris, and S. triqueter belong to the very difficult S. lacustris complex. The entire complex except S. triqueter was treated as the single species Scirpus lacustris (T. Koyama 1962b). Many Old World authors treat Schoenoplectus tabernaemontani as S. lacustris var. tabernaemontani or subsp. glaucus.

Much of the local infraspecific variation in the Schoenoplectus lacustris complex is probably because of hybridization. Some studies support the recognition of separate species in this group (J. Browning et al. 1995b). Hybrids in North America include S. acutus × S. tabernaemontani, widespread and common, especially in the east; S. acutus × S. heterochaetus = S. ×oblongus (T. Koyama) Soják, widespread but uncommon; S. heterochaetus × S. tabernaemontani = S. ×steinmetzii (Fernald) S. G. Smith, eastern and most uncommon; S. tabernaemontani × S. triqueter = S. ×kuekenthalianus (Junge) Kent, lower Columbia River in Oregon and probably Washington; and S. acutus var. occidentalis × S. californicus, local in California. Except for its trigonous culms, S. triqueter is very similar to the S. lacustris complex and freely hybridizes with S. tabernaemontani, both in North America and Europe.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 23, p. 51. FNA vol. 23, p. 47.
Parent taxa Cyperaceae > Schoenoplectus > sect. Schoenoplectus Cyperaceae > Schoenoplectus > sect. Schoenoplectus
Sibling taxa
S. acutus, S. americanus, S. californicus, S. deltarum, S. erectus, S. etuberculatus, S. hallii, S. heterochaetus, S. mucronatus, S. purshianus, S. saximontanus, S. smithii, S. subterminalis, S. tabernaemontani, S. torreyi, S. triqueter
S. acutus, S. americanus, S. californicus, S. deltarum, S. erectus, S. etuberculatus, S. hallii, S. heterochaetus, S. mucronatus, S. pungens, S. purshianus, S. saximontanus, S. smithii, S. subterminalis, S. torreyi, S. triqueter
Synonyms Scirpus pungens Scirpus tabernaemontani, Scirpus lacustris subsp. glaucus, Scirpus lacustris subsp. validus, Scirpus lacustris var. tabernaemontani, Scirpus validus, Scirpus validus var. creber
Name authority (Vahl) Palla: Verh. K. K. Zool.-Bot. Ges. Wien 38(Sitzungsber.): 49. (1888) (C. C. Gmelin) Palla: Verh. K. K. Zool.-Bot. Ges. Wien 38(Sitzungsber.): 49. (1888)
Web links