Carex aperta

Boott in W. J. Hooker

in W. J. Hooker, Fl. Bor-Amer. 2: 218, plate 219. 1839.

IllustratedEndemic
Synonyms: Carex accedens T. Holm Carex acutina var. tenuior L. H. Bailey Carex aperta var. umbrosa Kükenthal Carex aperta var. viridans Kükenthal Carex stylosa var. virens L. H. Bailey Carex turgidula
Treatment appears in FNA Volume 23. Treatment on page 395. Mentioned on page 381, 393.

Plants not cespitose. Culms acutely angled, 15–90 cm, scabrous. Leaves: basal sheaths redbrown; sheaths of proximal leaves with blades, backs glabrous, fronts with pale-brown spots, veinless, glabrous, apex U-shaped, membranous, colorless; blades 3–6 mm wide. Inflorescences: proximal bract subequal to inflorescence, 2–4 mm wide. Spikes: erect; proximal 2–3 spikes pistillate, 1.5–3.5 cm × 4–6 mm, base obtuse; terminal 1–2 spikes staminate. Pistillate scales redbrown, longer than perigynia, apex acute or acuminate, awnless. Perigynia divergent, olive-brown with redbrown spots on apical 1/2, veinless, inflated, loosely enclosing achenes, obovoid, 2.5–2.8 × 1.5–2 mm, dull, apex rounded, papillose; beak green, 0.1–0.3 mm. Achenes not constricted, dull. 2n = 54.


Phenology: Fruiting Jul–Aug.
Habitat: Wet meadows
Elevation: 0–900 m

Distribution

V23 703-distribution-map.jpg

Alta., B.C., Idaho, Mont., Oreg., Wash.

Discussion

Carex aperta and C. haydenii appear to be a very closely related, allopatric pair of species that may not be closely related to other members of the section. This species-pair is distinguished by the inflated perigynia, the acute scales that are longer than the perigynia, and the unique chromosome number. Carex aperta is distinguished from C. haydenii by its rhizomatous habit, the dull brown achenes, and the entire beak. It is sometimes mistaken for the sympatric taxa that also lack veins on the perigynia, C. aquatilis and C. scopulorum; mature specimens can easily be identified by the inflated perigynia.

Selected References

None.

Lower Taxa

None.
... more about "Carex aperta"
biconvex +
not constricted +
awnless +  and veinless +
pale-brown spots +
papillose +
redbrown spots +
Lisa A. Standley +, Jacques Cayouette +  and Leo Bruederle +
Boott in W. J. Hooker +
shortened +
not +  and fibrous +
bidentate +  and emarginate +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.03 cm0.3 mm <br />3.0e-4 m <br />) +
m--shaped +  and v--shaped +
3mm;6mm +
glumaceous +  and foliaceous +
2-ranked +  and arranged +
ascending +  and appressed +
scale-like +  and leaflike +
parallel +  and divergent +
terete +, rolled +  and plicate +
redbrown +  and brown +
15 cm150 mm <br />0.15 m <br /> (90 cm900 mm <br />0.9 m <br />) +
prophyllate +, subsessile +, pedunculate +  and staminate +
Alta. +, B.C. +, Idaho +, Mont. +, Oreg. +  and Wash. +
0–900 m +
open +, pistillate +  and staminate +
hypogynous +  and subtending +
membranous +
biconvex +  and trigonous +
Wet meadows +
multi-ranked +, 2-ranked +, 3-ranked +  and alternate +
basal +  and cauline +
with (1-)3-6(-30) bristles and/or scales +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.28 cm2.8 mm <br />0.0028 m <br />) +
spreading +, ascending +  and erect +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
Fruiting Jul–Aug. +
2-3(-4)-carpellate +
3 (?) +  and 1 (?) +
short-sheathing +, sheathless +  and leaflike +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
in W. J. Hooker, Fl. Bor-Amer. +
adventitious +
basal +  and proximal +
2-keeled +
ladder-fibrillose +  and veined +
cylindric +
Illustrated +  and Endemic +
staminate +  and pistillate +
1.5 cm15 mm <br />0.015 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
1 (?) +  and 3 (?) +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
deciduous +
2-3(-4)-fid +
Carex accedens +, Carex acutina var. tenuior +, Carex aperta var. umbrosa +, Carex aperta var. viridans +, Carex stylosa var. virens +  and Carex turgidula +
Carex aperta +
Carex sect. Phacocystis +
species +
, +  and staminate +
plant +  and not cespitose +