Scientific Name : Carex torreyi
Author : Tuckerman
NatureServe Explorer
Common Name : Torrey Sedge
Current Research Activities
☰ Click link below for details.
Taxonomy
Cyperaceae (sedge family)
Ranks and Status
State Rank : S1
State Rank Reason : Carex torreyi is known from seven occurrences along the Front Range of Colorado, USA. Potential threats include non-motorized recreation, competition from non-native plants and the long term effects of climate change.
U.S. Endangered Species Act : none
Colorado Threatened and Endangered List : none
Other Statuses : none
Description and Phenology
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, 2022). See also photograph of perigynia and pistillate scales in Ackerfield (2015, 2022).
Look Alikes:
Unknown.
Phenology:
Carex torreyi flowers from June through July.
 |
Habitat
In Colorado, this species is found in dry woodlands, gulches, shrubby slopes, and in fir and pine forests (Weber and Wittmann 2012, Ackerfield 2015, 2022). 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 lanceolata, Rubus idaeus, Corylus cornuta, and Toxicodendron rydbergii (Colorado National Heritage Program occurrence records 2017).
click on image to enlarge
 |
Elevation Range:
5,682 - 8,309 feet (1,732 - 2,533 meters)
Distribution
Colorado Endemic:
No
Range:
Carex torreyi is known from Jefferson, Boulder, and El Paso counties in Colorado, USA. Estimated range extent in Colorado of 1047 square kilometers was calculated in GeoCAT using occurrence data provided by the Colorado Natural Heritage Program (2023). This species also occurs in Minnesota, Montana, North Dakota, South Dakota, Wisconsin, and Wyoming USA. Globally, this species can also be found in Alberta, British Columbia, Manitoba, Ontario, and Saskatchewan, Canada (Flora of North America 2002), (NatureServe Network Database as of February 2017; USDA NRCS 2017).
 Click on map to enlarge |
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.
- Ackerfield, J. 2022. Flora of Colorado. Second Edition. Bot. Misc. 60. BRIT Press, Fort Worth Botanic Garden/Botanical Research Institute of Texas, U.S.A. 861 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 (CNHP). 2023. Biodiversity Tracking and Conservation System (Biotics 5). Colorado Natural Heritage Program, Colorado State University, Fort Collins.
- 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, ed. (FNA). 1993+. Flora of North America North of Mexico. Oxford Univ. Press, New York, Oxford.
- 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.
- Rydberg, P. A. Flora of the Rocky Mountains and Adjacent Plains. 2nd ed. Published by the author, New York: 1922.
- USDA, NRCS. 2022. The PLANTS Database. National Plant Data Team, Greensboro, NC 27401-4901 USA.
- 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.
