Oreoxis humilis
Author: Raf.

Pikes Peak spring parsley

Apiaceae (Carrot Family)

Close up of Oreoxis humilis by Steve Olson.
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Ranks and Status

Global rank: G1
State rank: S1
Federal protection status: USFS Sensitive
State protection status: None

[+] Description and Phenology

Oreoxis humilis by Sharon Eaton.
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General description: Oreoxis humilis is a perennial herb from 2 to 15 cm (0.78 to 5.9 inches) tall, but most frequently under 5 cm (1.97 inches) tall. Leaves are basal, 0.5 to 4.5 cm (0.20 to 1.77 inches) long and 0.5 to 1.0 cm (0.20 to 0.39 inches) wide. These are once or twice pinnately compound, each segment 1 to 2 mm (0.04 to 0.08 inch) wide and up to 10 mm (0.39 inch) long. Peduncles are up to 1 cm (0.39 inch) long. Umbels have several rays, each 2 to 5 mm (0.08 to 0.20 inch) long. The yellow flowers are subtended by involucel bracts. Plants are minutely hairy in the inflorescence. Fruits are winged, and are 3 to 5 mm (0.12 to 0.20 inch) long and 1.5 to 3 mm (0.06 to 0.12 inch) wide (Beatty et al. 2004, Ackerfield 2015).

Look Alikes: Oreoxis alpina (Alpine oreoxis) has finely puberulent fruit, while O. humilis fruit are glabrous. Oreoxis bakeri (Baker's alpineparsley) has involucel bracts that are broad, toothed, and sometimes purplish, while the bractlets of O. humilis are linear, entire and green (Spackman et al. 1997).

Phenology: Flowering occurs from June through August. Fruits appear in July and August (Beatty et al. 2004; Spackman et al. 1997).

[+] Habitat

Habitat of Oreoxis humilis by Steve Olson.
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Habitat of Oreoxis humilis by Steve Olson.
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Habitat of Oreoxis humilis by Steve Olson.
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This species occurs on tundra, fell fields, meadows, krumholtz, and open spruce-fir woodlands. It is known only from areas at or above timberline on rocks of Pikes Peak batholith (Pikes Peak granite and Windy Point granite). Plants have been found on slopes of up to 60 degrees, and on all aspects (Beatty, et al., 2004).  Associated species include: Kobresia myosuroides (Bellardi bog sedge), Pinus aristata (bristlecone pine), Polemonium viscosum (sticky polemonium), Saxifraga bronchialis (matted saxifrage), Paronychia pulvinata (Rocky Mountain nailwort), Mertensia alpina (alpine bluebells), Telesonix jamesii (James' telesonix), Cirsium scopulorum (mountain thistle), and Erigeron pinnatisectus (featherleaf fleabane).

Elevation Range: 9,636 - 12,812 feet (2,937 - 3,905 meters)

[+] Distribution

Distribution of Oreoxis humilis in Colorado according to mapped land ownership/management boundaries (CNHP 2015, COMaP v9).
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Distribution of Oreoxis humilis in Colorado.
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Colorado endemic: Yes
Global range: Endemic to Colorado; known only from the Pike's Peak vicinity in El Paso and Teller counties. Estimated range is 48 square kilometers (18 square miles), calculated in 2008 by the Colorado Natural Heritage Program in GIS by drawing a minimum convex polygon around the known occurrences.

[+] Threats and Management Issues

Summary results of an analysis of the status of Oreoxis humilis based on several ranking factors. This species was concluded to be “Moderately Conserved”. From Rondeau et al. 2011.
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Road erosion and construction are considered to be the primary threats to the species at this time (Rondeau et al. 2011). Oreoxis humilis is a species of concern because of its restricted geographic range, small number of documented occurrences, and possible vulnerability to human-related and environmental threats. Disturbances and land management activities may maintain suitable habitat for this species, or they may negatively impact existing occurrences, depending on the intensity, frequency, size, and type of disturbance and activity. Possible human-related threats to O. humilis include road erosion and construction, structure maintenance, and motorized and non-motorized recreational activities (Colorado Natural Heritage Program 2004). Possible environmental and biological threats to occurrences of O. humilis include environmental fluctuations, herbivory, genetic isolation, inadequate pollination, global climate changes, and exotic species invasion (Beatty et al. 2004).

Pikes Peak is popular for recreation activities and trampling is a threat. The largest threat is the Pikes Peak Highway which is dirt, highly used and maintained. Erosion problems are destroying habitat and possibly individuals. The Pikes Peak Multi-Use Plan (Design Workshop, Inc. 1999) developed by USFS and Colorado Springs Utilities does not specifically mention O. humilis, but it does outline plans to pave the Pikes Peak Toll Road to reduce sedimentation and to minimize trail creation to reduce trampling impacts on fragile tundra communities (Beatty et al. 2004). Paving of the Pikes Peak Toll Road started in 2001 and continues as part of a 12-year project (Beatty et al. 2004). On a larger scale, global warming potentially threatens this and other alpine species.

From Steve Olson (USFS Pike San Isabel) 2012: Sediment movement along the Pikes Peak Highway had been a concern, but since the paving of the road is nearly completed, the threat is essentially gone. There is a continuing lesser threat from unregulated recreation, such as user created trails in the alpine on Pikes Peak (Beatty, et al., 2004).

One modeling study of the Pikes Peak area suggests that the long term viability of Oreoxis humilis will be at risk given transportation and mitigation plans in the area (Casper et al. 2009).

[+] References

    • Ackerfield, J. 2012. The Flora of Colorado. Draft. Colorado State University Herbarium. 433 pp.
    • Ackerfield, J. 2015. Flora of Colorado. Brit Press, Botanical Research Institute of Texas, Fort Worth, TX. 818 pp.
    • Beatty, B.L., W.F. Jennings and R.C. Rawlinson. 2004. Oreoxis humilis Raf. (Rocky Mountain alpineparsley): A Technical Conservation Assessment. [Online]. USDA Forest Service, Rocky Mountain Region. http://www.fs.fed.us/r2/projects/scp/assessments/oreoxishumilis.pdf [2006-01-05]
    • Casper, C., M. A. Landon, P. J. Crist, and D. Walker. 2009a. Integrating conservation and long-range transportation planning using a strategic assessment framework. Road Ecology Center, John Muir Institute of the Environment, UC Davis. Permalink: http://escholarship.org/uc/item/5xg8z9gw [Accessed on Sept. 21, 2011].
    • Colorado Natural Heritage Program. 2005. The Second Annual Colorado Rare Plant Symposium: G1 Plants of Colorado. Symposium Minutes. Available on-line http://www.cnhp.colostate.edu/teams/botany.asp#symposia.
    • Design Workshop, Inc. 1999. Pikes Peak Multi-Use Plan. Unpublished report prepared for Colorado Springs Utilities, Colorado Springs, CO and U.S. Forest Service, Pikes Peak Ranger District, Colorado Springs, CO.
    • Harrington, H. D. 1954. Manual of the Plants of Colorado. Sage Books, Denver, CO. 666 pp.
    • 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.
    • Neely, B., S. Panjabi, E. Lane, P. Lewis, C. Dawson, A. Kratz, B. Kurzel, T. Hogan, J. Handwerk, S. Krishnan, J. Neale, and N. Ripley. 2009. Colorado Rare Plant Conservation Strategy, Developed by the Colorado Rare Plant conservation Initiative. The Nature Conservancy, Boulder, Colorado, 117 pp.
    • Rondeau, R., K. Decker, J. Handwerk, J. Siemers, L. Grunau, and C. Pague. 2011. The state of Colorado's biodiversity 2011. Prepared for The Nature Conservancy. Colorado Natural Heritage Program, Colorado State University, Fort Collins, Colorado.
    • Rydberg, P.A. 1906. Flora of Colorado. Bull. 100, Colorado Agricultural Experiment Station, Fort Collins, Colorado. 488pp.
    • Spackman, S., B. Jennings, J. Coles, C. Dawson, M. Minton, A. Kratz, and C. Spurrier. 1997. Colorado rare plant field guide. Prepared for Bureau of Land Management, U.S. Forest Service and U.S. Fish and Wildlife Service by Colorado Natural Heritage Program.
    • USDA, NRCS. 2013. 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.

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