Bolboschoenus fluviatilis

(Torrey) Soják

Cas. Nár. Mus., Odd. Prír. 141: 62. 1972.

Common names: River bulrush bolboschoenus fluviatile scirpe fluviatile
Illustrated
Basionyms: Scirpus maritimus var. fluviatilis Torrey Ann. Lyceum Nat. Hist. New York 3: 324. 1836
Synonyms: Scirpus fluviatilis (Torrey) A. Gray Schoenoplectus fluviatilis (Torrey) M. T. Strong
Treatment appears in FNA Volume 23. Treatment on page 42. Mentioned on page 38, 39, 40, 43.
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Culms 100–200 cm × 5–15 mm. Leaves: sheaths reaching to middle of culm or higher, fronts convex (to concave) and papery at mouth, veins reaching apex, very rarely diverging leaving triangular, veinless, membranous area; widest blade 7–22 mm wide. Inflorescences subumbellate, with all or most spikelets solitary or in clusters of 2–3 (–8) on 4–12 rays, rays not exceeding 10 cm; involucral-bracts that surpass inflorescences 3–6, widest bract 4–15 mm wide. Spikelets 10–40, ovoid to lanceoloid, 10–25 × 6–10 mm, base cuneate to rounded; scales often loosely imbricate, orangebrown to stramineous, usually obscurely lineolate-spotted, 7–10 × 3–4 mm, membranous and translucent, apex 2-fid 0.5–1 mm deep, awns fairly stout, 2–3 × 0.5 mm wide at base. Flowers: perianth bristles tightly attached to shed achene, pale-brown, very stout, equaling achene; anthers yellow, 4 mm; styles 3-fid. Achenes grayish or dark-brown, often in patches, obovoid to obpyriform, all nearly equilaterally markedly trigonous to slightly compressed, angles equally rounded, 3.8–5.5 × 2–2.9 mm, apex rounded, beak 0.2–0.8 mm, surface rather dull, exocarp cells usually not evident at 20X; in cross-section exocarp much thinner than mesocarp and its cells very small, isodiametric; achene specific gravity greater than water. 2n = 94.


Phenology: Fruiting summer.
Habitat: Fresh shores, inland marshes, coastal estuaries
Elevation: 0–2100 m

Distribution

V23 59-distribution-map.jpg

Alta., B.C., Man., N.B., Ont., Que., Sask., Ala., Ariz., Calif., Colo., Conn., Del., Idaho, Ill., Ind., Iowa, Kans., Maine, Md., Mass., Mich., Minn., Mo., Mont., Nebr., N.H., N.J., N.Y., N.Dak., Ohio, Oreg., Pa., S.Dak., Tenn., Utah, Vt., Va., Wash., Wis., Asia (Japan), Australia, Pacific Islands (New Zealand)

Discussion

Bolboschoenus fluviatilis frequently forms dense, monospecific, often entirely vegetative stands, and it is more common than recorded because vegetative colonies are often overlooked (E. W. Chester and B. E. Wofford 1992). The only record for Alabama is an 1870 collection from the East Fowl River in the Mobile Delta, where the species has not been collected since. It was intentionally introduced into New Hampshire (D. J. Padgett and G. E. Crow 1993). The report from New Mexico by M. L. Fernald (1950) cannot be confirmed because no specimen is known.

Putative hybrids with Bolboschoenus maritimus occur in California. Bolboschoenus novae-angliae probably originated from B. fluviatilis × B. robustus (J. Browning et al. 1995). Introgression from B. maritimus and/or B. robustus is suggested by the larger exocarp cells (evident in surface view) in some North American plants. The Eurasian B. yagara (Ohwi) Y. C. Yang & M. Zhan differs from B. fluviatilis in its narrower leaves and smaller achenes.

Selected References

None.

Lower Taxa

None.

... more about "Bolboschoenus fluviatilis"
dark-brown +  and grayish +
nearly equilaterally markedly trigonous;slightly compressed +
greater than water +
0.38 cm3.8 mm <br />0.0038 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
2mm;2.9mm +
4 cm40 mm <br />0.04 m <br /> (?) +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
triangular +
membranous +
S. Galen Smith +
(Torrey) Soják +
0.5 +, 2mm +  and 3mm +
shortened +
persistent +
cuneate +  and rounded +
Scirpus maritimus var. fluviatilis +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.08 cm0.8 mm <br />8.0e-4 m <br />) +
trigonous +, keeled +, v--shaped +  and flat +
glumaceous +  and foliaceous +
2-ranked +  and arranged +
ascending +  and appressed +
parallel +  and divergent +
terete +, rolled +  and plicate +
River bulrush +, bolboschoenus fluviatile +  and scirpe fluviatile +
100 cm1,000 mm <br />1 m <br /> (200 cm2,000 mm <br />2 m <br />) +
trigonous +
5mm;15mm +
Alta. +, B.C. +, Man. +, N.B. +, Ont. +, Que. +, Sask. +, Ala. +, Ariz. +, Calif. +, Colo. +, Conn. +, Del. +, Idaho +, Ill. +, Ind. +, Iowa +, Kans. +, Maine +, Md. +, Mass. +, Mich. +, Minn. +, Mo. +, Mont. +, Nebr. +, N.H. +, N.J. +, N.Y. +, N.Dak. +, Ohio +, Oreg. +, Pa. +, S.Dak. +, Tenn. +, Utah +, Vt. +, Va. +, Wash. +, Wis. +, Asia (Japan) +, Australia +  and Pacific Islands (New Zealand) +
0–2100 m +
much thinner +
hypogynous +  and subtending +
biconvex +  and trigonous +
Fresh shores, inland marshes, coastal estuaries +
multi-ranked +, 2-ranked +, 3-ranked +  and alternate +
cauline +  and basal +
curved +  and straight +
slightly longer +
with (1-)3-6(-30) bristles and/or scales +
shorter to slightly +
Fruiting summer. +
2-3(-4)-carpellate +
3 (?) +  and 1 (?) +
Cas. Nár. Mus., Odd. Prír. +
2 +  and 3 +
adventitious +
lineolate-spotted +, orangebrown +  and stramineous +
0.7 cm7 mm <br />0.007 m <br /> (1 cm10 mm <br />0.01 m <br />) +
basal +  and proximal +
glabrescent;puberulent +
2-keeled +
membranous +
3mm;4mm +
Illustrated +
0.4 cm4 mm <br />0.004 m <br /> (1 cm10 mm <br />0.01 m <br />) +
1 cm10 mm <br />0.01 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
10 +  and 40 +
ovoid;lanceoloid +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
Scirpus fluviatilis +  and Schoenoplectus fluviatilis +
Bolboschoenus fluviatilis +
Bolboschoenus +
species +
notched +
herb +, not +  and cespitose +
7mm +  and 22mm +
0.4 cm4 mm <br />0.004 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +