Schoenoplectus saximontanus

(Fernald) J. Raynal

Adansonia, n. s. 16: 141. 1976.

Common names: Rocky Mountain bulrush
Illustrated
Basionym: Scirpus saximontanus Fernald Rhodora 3: 251. 1901
Synonyms: Scirpus bergsonii Schuyler Scirpus supinus var. saximontanus (Fernald) T. Koyama
Treatment appears in FNA Volume 23. Treatment on page 59. Mentioned on page 46, 55, 60.

Plants annual or perennial; rhizomes 1 mm diam. Culms often arching to decumbent, cylindric, ridged when dry, 0.09–0.65 m × 0.5–1.5 mm. Leaves 3–4, 1 (–2) cauline; sheath fronts not pinnate-fibrillose; blades 1–2, proximally thickly C-shaped in cross-section, distally flat, rudimentary to longer than sheath, 1–200 × 0.2–1 mm, smooth or margins distally spinulose. Inflorescences capitate or of 1 spikelet or with 1 or 2 branches to 15 mm; proximal bract erect, like leaf-blades, 5–15 cm. Spikelets 1–20; 6–20 × 3 mm; scales pale orangebrown to colorless, midrib region sometimes greenish, ovate, 2.2–3 (–3.5) × 1.5 mm, awn sparsely spinulose, margins ciliolate, midrib keeled distally, apex entire, rounded, awn 0.2–0.5 mm or to 1 mm on proximal scale. Flowers: perianth absent; anthers 0.3–0.5 mm; styles 3-fid. Spikelet achenes blackish brown, nearly equilaterally sharply trigonous, ovoid to obovoid, 1.3–1.8 × 1–1.4 mm, with 10–20 mostly sharp ridges; beak 0.1 mm. Amphicarpic achenes trigonous, 2.2–3 mm including stout, tapered beak 0.3 mm, with many obscure to evident horizontal ridges. 2n = 50.


Phenology: Fruiting late summer–fall, spring–fall (California, Texas).
Habitat: Damp soils to emergent, freshwater ponds, ditches, often drying, disturbed, and sandy areas
Elevation: 0–2200 m

Distribution

V23 88-distribution-map.jpg

B.C., Calif., Colo., Ill., Kans., Mo., Nebr., Ohio, Okla., S.Dak., Tex., Utah, Wyo., Mexico (San Luis Potosí), Mexico (Tamaulipas)

Discussion

The distribution of Schoenoplectus saximontanus is very scattered (local).

Selected References

None.

Lower Taxa

None.

No values specified."prolonged" is not a number.

with transverse wavy ridges +  and rugose +
trigonous +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
S. Galen Smith +
(Fernald) J. Raynal +
shortened +
deciduous +
enlarged +
Scirpus saximontanus +
tapered +
0.1 cm1 mm <br />0.001 m <br /> (?) +
5 cm50 mm <br />0.05 m <br /> (15 cm150 mm <br />0.15 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (20 cm200 mm <br />0.2 m <br />) +
rudimentary +
1 (?) +  and 2 (?) +
c--shaped +
0.2mm;1mm +
glumaceous +  and foliaceous +
2-ranked +  and arranged +
ascending +  and appressed +
parallel +  and divergent +
terete +, rolled +  and plicate +
Rocky Mountain bulrush +
dorsiventrally flat +  and c-shaped or laterally compressed +
9 cm90 mm <br />0.09 m <br /> (65 cm650 mm <br />0.65 m <br />) +
arching +  and decumbent +
ridged +  and cylindric +
0.5mm;1.5mm +
B.C. +, Calif. +, Colo. +, Ill. +, Kans. +, Mo. +, Nebr. +, Ohio +, Okla. +, S.Dak. +, Tex. +, Utah +, Wyo. +, Mexico (San Luis Potosí) +  and Mexico (Tamaulipas) +
0–2200 m +
hypogynous +  and subtending +
biconvex +  and trigonous +
Damp soils to emergent, freshwater ponds, ditches, often drying, disturbed, and sandy areas +
of 1 spikelet or with 1 or 2branches 0-15 mm +  and capitate +
multi-ranked +, 2-ranked +, 3-ranked +  and alternate +
cauline +  and basal +
membranous +
0.3 cm3 mm <br />0.003 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
0.22 cm2.2 mm <br />0.0022 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (?) +
curved +  and straight +
with (1-)3-6(-30) bristles and/or scales +
Fruiting late summer–fall, spring–fall (California, Texas). +
2-3(-4)-carpellate +
3 (?) +  and 1 (?) +
Adansonia, n. s. +
1 cm10 mm <br />0.01 m <br /> (?) +
inconspicuous +
obscure +  and evident +
adventitious +
pale orangebrown +  and colorless +
deciduous +
basal +  and proximal +
2-keeled +
not pinnate-fibrillose +
Illustrated +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
ovoid +  and obovoid +
0.1 cm1 mm <br />0.001 m <br /> (0.14 cm1.4 mm <br />0.0014 m <br />) +
0.6 cm6 mm <br />0.006 m <br /> (2 cm20 mm <br />0.02 m <br />) +
1 +  and 20 +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
Scirpus bergsonii +  and Scirpus supinus var. saximontanus +
Schoenoplectus saximontanus +
Schoenoplectus sect. Supini +
species +
not +  and rhizomatous +
perennial +  and annual +