Schoenoplectus mucronatus

(Linnaeus) Palla

Verh. K. K. Zool.-Bot. Ges. Wien 38(Sitzungsber.): 49. 1888.

Common names: Rough-seed bulrush ricefield bulrush
IntroducedIllustrated
Basionym: Scirpus mucronatus Linnaeus Sp. Pl. 1: 50. 1753
Treatment appears in FNA Volume 23. Treatment on page 58. Mentioned on page 46, 55.

Plants perennial (or annual?); rhizomes hard. Culms sharply trigonous, 0.4–1 m × 2–3 mm. Leaves 1–2; sheath fronts not pinnate-fibrillose; ligules absent; blades absent. Inflorescences capitate; proximal bract divergent to reflexed or rarely erect, trigonous, adaxially channeled, 1–10 cm. Spikelets 4–20, 7–12 × 4 mm; scales orangebrown to straw-colored, central region often greenish, broadly obovate, 3–3.5 × 2–2.5 mm, margins ciliolate, apex obtuse to broadly acute, entire, mucronate. Flowers: perianth members 6, brown, bristlelike, equaling achene, stout, retrorsely spinulose; anthers 0.8 mm; styles 3-fid (or some 2-fid in same spikelet). Achenes dark to blackish brown, thickly planoconvex to obtusely trigonous, broadly obovoid, 1.7–2.2 (–2.5) × 1.2–1.7 mm; beak 0.2 mm.


Phenology: Fruiting summer–fall.
Habitat: Wet soil to emergent in fresh water, ponds, ditches, rice fields
Elevation: 20–300 m

Distribution

V23 86-distribution-map.jpg

Introduced; Calif., Ill., Iowa, Ky., Mo., Tenn., Eurasia, Africa, Australia

Discussion

Schoenoplectus mucronatus was collected before 1900 in New Brunswick and New Jersey; apparently the plants did not persist. It has also been reported from New York and Pennsylvania; I have not seen specimens. Elsewhere, it has become firmly established. It is an important ricefield weed in California (M. K. Bellue 1947), where it was first observed in 1942 and is called “ricefield bulrush.” It was first observed in the Midwest in 1971. Schoenoplectus mucronatus is cultivated for wildlife food near the Columbia River in Clark County, Washington, but apparently is not established in that area. Schoenoplectus mucronatus is very similar to S. triangulatus (Roxburgh) Soják of Asia, which differs in its larger spikelets, spikelet scales, and anthers.

Selected References

None.

Lower Taxa

None.

"prolonged" is not a number.

... more about "Schoenoplectus mucronatus"
0.22 cm2.2 mm <br />0.0022 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
dark +  and blackish brown +
0.17 cm1.7 mm <br />0.0017 m <br /> (0.22 cm2.2 mm <br />0.0022 m <br />) +
obovoid;thickly planoconvex;obtusely trigonous +
1.2mm;1.7mm +
0.8 cm8 mm <br />0.008 m <br /> (?) +
S. Galen Smith +
(Linnaeus) Palla +
shortened +
deciduous +
enlarged +
Scirpus mucronatus +
0.2 cm2 mm <br />0.002 m <br /> (?) +
rudimentary +
glumaceous +  and foliaceous +
2-ranked +  and arranged +
ascending +  and appressed +
parallel +  and divergent +
terete +, rolled +  and plicate +
0.3 cm3 mm <br />0.003 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
2mm +  and 2.5mm +
Rough-seed bulrush +  and ricefield bulrush +
dorsiventrally flat +  and c-shaped or laterally compressed +
0.5mm +  and 3mm +
40 cm400 mm <br />0.4 m <br /> (100 cm1,000 mm <br />1 m <br />) +
trigonous +
2mm;3mm +
Calif. +, Ill. +, Iowa +, Ky. +, Mo. +, Tenn. +, Eurasia +, Africa +  and Australia +
20–300 m +
hypogynous +  and subtending +
biconvex +  and trigonous +
Wet soil to emergent in fresh water, ponds, ditches, rice fields +
multi-ranked +, 2-ranked +, 3-ranked +  and alternate +
cauline +  and basal +
membranous +
curved +  and straight +
with (1-)3-6(-30) bristles and/or scales +
Fruiting summer–fall. +
2-3(-4)-carpellate +
3 (?) +  and 1 (?) +
channeled;trigonous +
1 cm10 mm <br />0.01 m <br /> (10 cm100 mm <br />0.1 m <br />) +
Verh. K. K. Zool.-Bot. Ges. Wien +
inconspicuous +
distinct +
adventitious +
orangebrown +  and straw-colored +
deciduous +
basal +  and proximal +
2-keeled +
not pinnate-fibrillose +
W1 +, Introduced +  and Illustrated +
0.7 cm7 mm <br />0.007 m <br /> (1.2 cm12 mm <br />0.012 m <br />) +
4 +  and 20 +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
Schoenoplectus mucronatus +
Schoenoplectus sect. Actaeogeton +
species +
not +  and rhizomatous +