Carex assiniboinensis

W. Boott

Bot. Gaz. 9: 91. 1884.

Common names: Assiniboia sedge
IllustratedEndemic
Treatment appears in FNA Volume 23. Treatment on page 468. Mentioned on page 255, 462.

Plants densely cespitose, also producing long-arching stolons that root at the tip and form new plants. Culms dark maroon at base; flowering-stems 35–75 cm, longer than leaves at maturity, 0.5–0.8 mm thick, glabrous or minutely scabrous on angles, especially within inflorescence. Leaves: basal sheaths maroon, bladeless, glabrousl; others grading from maroon to green on back, pale hyaline on front; blades flat, 1–3 mm wide, glabrous on adaxial surface, often strigose on abaxial surface, margins and midribs of abaxial surface scabrous at distal end. Inflorescences: peduncles of lateral spikess 20–60 mm, glabrous; peduncle of ternimal spike 40–60 mm, glabrous or minutely scabrous on angles; proximal bracts much shorter than inflorescence; sheaths 15–25 mm; blades 1.5–2.2 mm wide. Lateral spikes 2–5, pistillate with fewer than 10 perigynia attached 3–15 mm apart, 1 spike per node, well separated, erect or drooping, linear, 5–30 × 3–5 mm; distal spikes sometimes staminate and shorter than terminal spike. Terminal spike staminate, 11–30 × 1.5–3 mm. Pistillate scales pale hyaline, often partially suffused with chestnut-brown, with narrow green midrib, lanceolate to oblong, shorter than mature pergiynia, apex cuspidate or acuminate with serrulate green awn 1–3 mm, glabrous. Perigynia green, at least body maturing to yellow, 2-ribbed but not obviously otherwise veined, except sometimes near base, tightly enveloping achene, lanceellipsoid, 5–6.5 × 0.8–1.8 mm, cartilaginous, base with stipe 0.5 mm, apex tapering gradually to beak, short-pubescent; beak oblique to minutely toothed, 2.5 mm. Achenes stipitate, 1.8–2.5 × 0.7–1 mm, stipe adnate to thickened perigynium base, breaking from achene at maturity. 2n = 32.


Phenology: Fruiting summer.
Habitat: Floodplain forests, old river channels and riverbanks, mesic deciduous and mixed conifer-hardwood forests, thickets

Distribution

V23 857-distribution-map.jpg

Man., Ont., Sask., Iowa, Mich., Minn., N.Dak., S.Dak., Wis.

Discussion

Carex assiniboinensis is easy to recognize in mid to late summer because it forms long-arching stolons that root at the tip to form new plantlets. The stoloniferous habit, which was given taxonomic status as C. assiniboinensis forma ambulans by J.-P. Bernard (1959), is typical for the species. Although some herbarium specimens lack the stolons because they were collected early in the season, most if not all populations appear to form the stolons by late summer.

Selected References

None.

Lower Taxa

None.

"thick" is not a number.

... more about "Carex assiniboinensis"
0.18 cm1.8 mm <br />0.0018 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
trigonous +
0.7mm;1mm +
short-pubescent +  and glabrous +
Marcia J. Waterway +
W. Boott +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
shortened +
rounded +  and tapering +
Hymenochlaenae +
1/2 length of body +
oblique +  and minutely toothed +
2.5 cm25 mm <br />0.025 m <br /> (?) +
strigose +  and glabrous +
m--shaped +
1.5mm;2.2mm +
0.5 cm5 mm <br />0.005 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
glumaceous +  and foliaceous +
2-ranked +  and arranged +
ascending +  and appressed +
scale-like +  and leaflike +
parallel +  and divergent +
terete +, rolled +  and plicate +
Assiniboia sedge +
dark maroon +
round +  and trigonous +
Man. +, Ont. +, Sask. +, Iowa +, Mich. +, Minn. +, N.Dak. +, S.Dak. +  and Wis. +
open +, pistillate +  and staminate +
hypogynous +  and subtending +
35 cm350 mm <br />0.35 m <br /> (75 cm750 mm <br />0.75 m <br />) +
biconvex +  and trigonous +
Floodplain forests, old river channels and riverbanks, mesic deciduous and mixed conifer-hardwood forests, thickets +
nodding +  and erect +
0.3 cm3 mm <br />0.003 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
multi-ranked +, 2-ranked +, 3-ranked +  and alternate +
basal +  and cauline +
entire +  and bidentate +
pale hyaline +, maroon +  and green +
scabrous +  and glabrous +
4 cm40 mm <br />0.04 m <br /> (6 cm60 mm <br />0.06 m <br />) +
with (1-)3-6(-30) bristles and/or scales +
stipitate +, veinless +  and veined +
ascending +  and erect +
0.2 cm2 mm <br />0.002 m <br /> (1 cm10 mm <br />0.01 m <br />) +
Fruiting summer. +
2-3(-4)-carpellate +
, +, suffused with maroon or suffused with chestnut-brown +, white +  and hyaline +
3 (?) +  and 1 (?) +
adventitious +
suffused with chestnut-brown +  and pale hyaline +
shorter than mature pergiynia +
basal +  and proximal +
lanceolate;oblong +
cylindric +
1.5 cm15 mm <br />0.015 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
Illustrated +  and Endemic +
0.5 cm5 mm <br />0.005 m <br /> (3 cm30 mm <br />0.03 m <br />) +
drooping +  and erect +
0.3 cm3 mm <br />0.003 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
1 (?) +  and 3 (?) +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
0.5 cm5 mm <br />0.005 m <br /> (?) +
long-arching +
deciduous +
2-3(-4)-fid +
Carex assiniboinensis +
Carex sect. Hymenochlaenae +
species +
androgynous +  and gynecandrous +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0 cm0 mm <br />0 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
plant +  and cespitose +
pubescent +  and glabrous +
not septate-nodulose +