Carex torreyi
Author: Tuckerman

Torrey sedge

Cyperaceae (Sedge Family)

Close up of Carex torreyi by Pamela Smith.
Click image to enlarge.

Ranks and Status

Global rank: G4G5
State rank: S1
Federal protection status: None
State protection status: None

[+] Description and Phenology

Carex torreyi from the USDA-NRCS PLANTS Database, Britton and Brown 1913.
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General description: Plants stand 15–50 cm tall. Culms (stems) leaf sheaths and blades have sparse, long, soft hairs (pilose). Ligules are longer than wide. Bracts are inconspicuous or the lower leaf-like and shorter than the inflorescence. Inflorescences: spikes 2-4, terminal spike staminate and the lateral spikes gynaecandrous or pistillate. Pistillate scales ovate, shorter than perigynia, apex obtuse to acuminate. Staminate scales ovate, 3.2–4.1 mm, apex acute or acuminate. Anthers 1.9–2.4 mm. Perigynia ascending, yellowish-green, strongly 18–24-veined, ovate or obovate, 2.2–3.2 × 1.5–2.2 mm, glabrous; beak 0.2–0.5 (1) mm (virtually beakless). Achenes 2–2.5 × 1.5–1.9 mm (FNA 2002, Weber and Whittmann 2012, Ackerfield 2015).  See also photograph of perigynia and pistillate scales in Ackerfield (2015).

Look Alikes:

Phenology: Carex torreyi flowers from June through July.

[+] Herbarium Photos

Images of Carex torreyi housed at the Colorado State University Herbarium.

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Click image to enlarge.

[+] Habitat

Habitat of Carex torreyi by Pamela Smith.
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In Colorado, this species is found in dry woodlands, gulches, shrubby slopes, and in fir and pine forests (Weber and Wittmann 2012, Ackerfield 2015). Also found in a Gambel Oak/ Douglas Fir/ Ponderosa Pine Forest, on grassy slopes, in openings among Ponderosa Pine, at the base of talus slides, and rooted between loose rocks, but in the shade of mesic herbs and shrubs. Associated species include: Juniperus communis, Carex saximontana, Carex deweyana, Thalictrum fendleri, Geranium richardsonii, Carex microptera, Dodecatheon pulchellum, Betula fontinalis, Rosa woodsii, Geum macrophyllum, Heracleum sphondylium, Scrophularia lanceolataRubus idaeus, Corylus cornuta, and Toxicodendron rydbergii (Colorado National Heritage Program occurrence records 2017). 

Elevation Range: 6,660 - 8,307 feet (2,030 - 2,532 meters)

[+] Distribution

Distribution of Carex torreyi in Colorado according to mapped land ownership/management boundaries (CNHP 2017, COMaP).
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Distribution of Carex torreyi in Colorado.
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Colorado endemic: No
Global range: Carex torreyi has been documented from Alberta to Saskatchewan south to Colorado, South Dakota, and Wisconsin (Flora of North America 2002), and in British Columbia and Ontario (NatureServe Network Database as of February 2017; USDA NRCS 2017).
State range: Jefferson, Boulder, and El Paso Counties.

[+] Threats and Management Issues

One Colorado occurrence reports concerns about non-motorized recreation and competition from non-native plants. Colorado climate scenarios for 2050 suggest temperature will increase by 3-7 F and precipitation may decrease or increase. The impact to any given rare plant habitat is likely to vary. Long-term monitoring that includes weather and soil moisture data is critical to understanding climate impacts.

[+] References

    • Ackerfield, J. 2015. Flora of Colorado. Brit Press, Botanical Research Institute of Texas, Fort Worth, TX. 818 pp.
    • Britton, N. L. and A. Brown. 1913. An Illustrated Flora of the Northern United States and Canada. 3 vol. Dover Publications, Inc., N. Y. 2052 pp.
    • Colorado Natural Heritage Program and the Geospatial Centroid. 2017. The Colorado Ownership and Protection Map (COMaP). Colorado State University, Ft. Collins, CO.
    • Flora of North America Editorial Committee. 2002. Flora of North America north of Mexico. Vol. 23. Magnoliophyta: Commelinidae (in part): Cyperaceae. Oxford Univ. Press, New York. xxiv + 608 pp.
    • Harrington, H. D. 1954. Manual of the Plants of Colorado. Sage Books, Denver, CO. 666 pp.
    • Hermann, F. J. 1970. Manual of the Carices of the Rocky Mountains and Colorado Basin. U.S.D.A. Forest Service Agriculture Handbook No. 374.
    • Kartesz, J.T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. 2nd edition. 2 vols. Timber Press, Portland, OR.
    • Rydberg, P. A. Flora of the Rocky Mountains and Adjacent Plains. 2nd ed. Published by the author, New York: 1922.
    • USDA, Natural Resources Conservation Service, PLANTS Database [USDA PLANTS]. Accessed 2017.
    • Weber, W. A. and R. C. Wittmann. 2012. Colorado Flora, Eastern Slope, A Field Guide to the Vascular Plants, Fourth Edition. Boulder, Colorado. 555 pp.

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