FEIS Home Page |
|
|
|
Craig Bihrle @ ND Game and Fish |
AUTHORSHIP AND CITATION:
Groen, Amy H. 2005. Echinacea angustifolia.
In: Fire Effects Information System, [Online].
U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station,
Fire Sciences Laboratory (Producer). Available:
https://www.fs.usda.gov/database/feis/plants/forb/echang/all.html [].
FEIS ABBREVIATION:
ECHANG
SYNONYMS:
None
NRCS PLANT CODE [103]:
ECAN2
ECANA
ECANS
COMMON NAMES:
purple coneflower
narrow-leaved coneflower
blacksamson
TAXONOMY:
The currently accepted scientific name for purple coneflower is Echinacea angustifolia
DC (Asteraceae) [8,30,45,55]. There are 2 recognized varieties:
E. a. var. angustifolia
E. a. var. strigosa (R.L. McGreg) [45,55]
Throughout this review, purple coneflower will refer to both varieties, E. a. var. angustifolia and E. a. var. strigosa. The literature does not differentiate between the 2 infrataxa, so distinction between the varieties will only be made in the distribution and occurrence section.
Hybrids: In an experimental garden setting, E. a. var. angustifolia
was successfully crossed with eastern purple coneflower (E. purpurea) [70].
LIFE FORM:
Forb
FEDERAL LEGAL STATUS:
None
OTHER STATUS:
In Wyoming, purple coneflower has been assigned a state ranking of 3 and a
global ranking of 4, with 1 being rare and 5 being abundant [39].
In Missouri, purple coneflower is listed as critically imperiled at the state
level and as a long-term concern at the global level [72].
CO | IL | IA | KS | KY | LA | MN | MO |
MT | NE | NM | ND | OK | SD | TX | WY |
AB | MB | SK |
Grasses: Purple coneflower is frequently associated with the following graminoid species: little bluestem (Schizachyrium scoparium), big bluestem (Andropogon gerardii var. gerardii), indiangrass (Sorghastrum nutans), Kentucky bluegrass (Poa pratensis), blue grama (Bouteloua gracilis), sideoats grama (B. curtipendula), needle-and-thread grass (Hesperostipa comata), and western wheatgrass (Pascopyrum smithii) [2,4,11,17,18,19,21,23,28,32,39,48,67,69,73,75,77,80,81,85,89,98,100,102,104,114].
Shrubs and forbs: In Nebraska, species commonly found with purple coneflower include flowering spurge (Euphorbia corollata), downy phlox (Phlox pilosa), wholeleaf rosinweed (Silphium integrifolium), and white prairieclover (Dalea candida) [17]. In Kansas, it can be found alongside prairie bundleflower (Desmanthus illinoensis), compassplant (S. laciniatum) [33], dotted blazing star (Liatris punctata), and desert princesplume (Stanleya pinnata) [65]. In North Dakota, it occurs with western snowberry (Symphoricarpos occidentalis), heath aster (Aster ericoides var. ericoides), Louisiana sagewort (Artemisia ludoviciana) [28], western yarrow (Achillea millefolium), sagewort wormwood (Artemisia campestris), and scarlet beeblossom (Gaura coccinea) [16].
Trees: Purple coneflower has been observed in scattered and open interior ponderosa pine (Pinus ponderosa var. scopulorum) stands in Nebraska [102] and sand shinnery oak (Quercus havardii) communities in Oklahoma [18]. In Illinois, purple coneflower was present near a forest of post oak (Q. stellata), chinquapin oak (Q. muehlenbergii), and eastern redcedar (Juniperus virginiana), populating the area after tree removal and prescribed fire [73].
Purple coneflower is a native, warm season perennial forb that can reach heights of 2.5 feet (76 cm). Seed heads are found on 2 to 5 stems which project 6 to 10 inches (15-25 cm) above the leaves [54]. Purple coneflower supports alternate leaves which are oblong to lance-shaped with 3 to 5 nerves [59]. Basal leaves are 2.0 to 10.6 inches (5-27 cm) in length and 0.4 to 1.6 inches (1-4 cm) wide. Lower cauline leaves are 1.6 to 5.9 inches (4-15 cm) in length and 0.2 to 1.5 inches (0.5-3.8 cm) wide. Upper cauline leaves lack a petiole and are 0.6 to 1.2 inches (1.5-3 cm) high and 0.6 to 1.0 inches (1.5-2.5 cm) wide [70]. Short, stiff hairs encompass both the leaves and stems of purple coneflower [54]. Flowers are 0.8 to 1.6 inches (2-4 cm) long and 0.16 to 0.20 inch (4-5 mm) wide [59].
Plants located in the high plains of Texas and north into Canada are characterized by low heights and flowers that are equal in length or shorter than the width of the disk. As you travel eastward in its range, purple coneflower becomes progressively taller with longer rays [70].
Purple coneflower has a very fragile tap root [7] which is "large" [54] and extends 4.7 to 6.5 feet (1.5-2 m) into the soil [8]. During times of water stress, root growth is emphasized over foliar development and signs of chlorosis may be evident [32]. In a greenhouse study, it was found that purple coneflower responds favorably to the presence of mycorrhizae, experiencing a significant (P≤0.001) increase in mean dry mass weight [111].
Three populations of purple coneflower tested for allelopathic
properties in a greenhouse setting displayed adverse effects on 2
potential competitors (switchgrass (Panicum virgatum) and prairie
dropseed (Sporobolus heterolepis)) [105]. Further studies are needed to determine
allelopathic properties of purple coneflower in a field setting.
RAUNKIAER [84] LIFE FORM:
Geophyte
REGENERATION PROCESSES:
Purple coneflower was thought to reproduce exclusively by seed [10]; however,
15-25% of plants will sprout after removal of the top 6 to 8 inches (15.2-20.3
cm) of root material during cultivation (Kindscher, personal communication [60]).
Breeding system: No additional information is available on this topic.
Pollination: Purple coneflower is pollinated by insects [9]. Availability of pollen is determined by population size. Isolated plants experience greater pollen limitation [107].
Seed production: Purple coneflower relies on seed production to regenerate [76]. Plants begin to produce seed after 1 year of growth [29], with seed yield correlated to pollen availability [107]. In Kansas purple coneflower was the only forb that continued to produce seed in the 3 years following a 7-year drought [22].
Seed dispersal: Purple coneflower disperses its seed gradually from early fall to early summer [32]. Due to the lack of any specialized mechanism for seed dispersal, it is improbable that purple coneflower would colonize habitats distant from a seed source [76].
Seed banking: In a study intended to determine regeneration of plants after 7 years of drought in Hays, Kansas, viable purple coneflower seeds were found in the top 0.5 in (1.3 cm) of soil [67].
Germination: Purple coneflower seeds germinate on the surface of warm, moist soils at temperatures of 68 °F (20 °C) and above during spring months [32] before they are fully afterripened [10]. The seed has a corky covering that, when removed, allows for increased rates of germination. Thirteen percent of seeds with the covering germinated in 5 to 11 days and 92% of seeds without the covering germinated in 2 to 9 days [97].
Purple coneflower's need for stratification is unclear. In a study conducted by Baskin and others [10], 12 weeks of cold stratification were considered essential for seeds to overcome dormancy. In a separate study, it was determined that purple coneflower had low germination rates that were not improved by stratification or presowing treatments [93]. In Montana, purple coneflower seeds 3 months to 3 years of age germinated in high numbers regardless of stratification [32]. By placing seeds on a moist filter paper substrate in the dark and setting a constant temperature of 70 °F (21 °C), Owens and Call [78] observed a germination rate of 92% in 9 days for purple coneflower. When subjected to various thermoperiods and light/dark conditions, purple coneflower seeds displayed a variety of germination rates [10]. By allowing germination to occur in a greenhouse with the use of light, Smith-Jochum and Albrecht [95] found an increase in rates when compared with field germination.
Various treatments have exhibited positive effects on germination rates of purple coneflower. Gao and others found that treating seeds with 5.3M of KOH for 10 minutes increased germination from 30% to 90% and emergence from 12% to 90% [42]. Seeds treated with 1.0 mM of ethephon solution and kept under constant light showed a 29% increase in germination rates. Untreated seeds germinated at a rate of 50% to 60% [88].
Seedling establishment/growth: In a study conducted on 1,249 purple coneflower seedlings, population fragmentation was a significant indicator of seedling vigor [107]. One hundred percent of purple coneflower seeds collected in South Dakota were found to be viable and 76.5% developed mature embryos [97].
Asexual regeneration: While Bare [8] and Umbanhowar [104] maintain that purple coneflower is rhizomatous, Kindscher suggests that it is a tap-rooted species devoid of rhizomes (Kindscher, personal communication [60]). Kaul was also not able to detect any rhizomes on purple coneflower (Kaul, personal communication [58]). Further research may be necessary to verify the existence or absence of rhizomes in purple coneflower.
Purple coneflower can be propagated through cuttings from the thick taproot [47]. Mass propagation can be done
using axillary bud proliferation, adventitious shoot formation and somatic embryogenesis [64], potentially
producing plants on a scale suitable for commercial needs.
SITE CHARACTERISTICS:
Purple coneflower is most often associated with the Great Plains region [2,16]. It grows primarily in open, rocky
prairies and plains [45], but also occurs in drainages and depressions [28]. It has been found in scattered and open
ponderosa pine stands [102], cedar glades [11], and along fenced roadsides devoid of grazing pressures [33].
Climate: Purple coneflower occurs on mesic sites [28] with average annual precipitation ranging from a low of 15.9 inches (404 mm) in southeastern North Dakota [25] to a high of 40.0 inches (1,016 mm) in central Texas [2]. A gauging station in southeastern North Dakota recorded an average temperature of 41.1 °F (5.1 °C) with low and high temperatures of 6.3 °F (14.3 °C) and 71.2 °F (21.8 °C), respectively [77].
Soils: Purple coneflower tolerates a variety of soil types throughout its range.
State | Soil description |
Kansas | alkaline soils [65] soils with a low percentage of organic matter [67] |
Minnesota | dry, sandy exposed sites [23] |
North Dakota | glacial till plains [25,77] fluvial mediums capped by aeolian sand and silt [28] |
Nebraska | silty loess derived soils [17,20] shallow range sites containing lime [85] |
Texas | dark, calcareous clays and gray, sandy loams [2] |
Earliest first bloom |
Latest first bloom |
Median date of full flowering |
Median date when 95% of flowering complete |
Length of flowering period (days) |
June 20th |
July 12th |
July 11th |
August 2nd |
27 |
Fire regimes: The following table provides fire return intervals for plant communities and ecosystems where purple coneflower is important. Find further fire regime information for the plant communities in which this species may occur by entering the species name in the FEIS home page under "Find Fire Regimes".
Community or Ecosystem | Dominant Species | Fire Return Interval Range (years) |
bluestem prairie | Andropogon gerardii var. gerardii-Schizachyrium scoparium | < 10 [61,79] |
plains grasslands | Bouteloua spp. | < 35 [79,113] |
blue grama-needle-and-thread grass-western wheatgrass | Bouteloua gracilis-Hesperostipa comata-Pascopyrum smithii | < 35 [79,86,113] |
blue grama-buffalo grass | Bouteloua gracilis-Buchloe dactyloides | < 35 [79,113] |
cedar glades | Juniperus virginiana | 3-22 [46,79] |
wheatgrass plains grasslands | Pascopyrum smithii | < 5-47+ [79,83,113] |
interior ponderosa pine* | Pinus ponderosa var. scopulorum | 2-30 [5,6,66] |
oak-hickory | Quercus-Carya spp. | < 35 |
post oak-blackjack oak | Quercus stellata-Q. marilandica | < 10 [106] |
little bluestem-grama prairie | Schizachyrium scoparium-Bouteloua spp. | < 35 [79] |
Palatability/nutritional value: Purple coneflower is utilized by livestock and provides nutritious forage where available. In Montana, it is considered a warm season, high-producing plant that is palatable to grazing animals, but subject to population declines under heavy grazing pressures [63]. In Kansas, populations are drastically reduced in grazed areas but continue to do well along fenced roadside borders [33]. On test plots in southern Minnesota, purple coneflower was found to be undesirable as browse for white-tailed deer, eastern cottontails, and ground squirrels [36]. Mature plants are inedible to cattle [89].
Purple coneflower has been successfully added to the feed of undernourished cows and horses in order to stimulate appetite [59].
Cover value:
In the Loess Hill prairies of western Iowa, purple coneflower occurs in the prairie-obligate
skipper butterfly's habitat [90].
VALUE FOR REHABILITATION OF DISTURBED SITES:
Purple coneflower is valuable for the restoration of prairies in the Great
Plains region. In central Texas, container grown transplants were a successful
part of the Blackland Prairie restoration effort [2]. At the Heard Museum in eastern Texas,
strips of sod transplanted from a nearby area and supporting a similar composition of species
displayed an initial decrease and subsequent increase in cover and frequency
of purple coneflower [98]. In Kansas, purple coneflower plants were grown in a greenhouse and
inoculated with Rhizobium bacteria before being transplanted. Two seedlings planted
in 1984 survived year 1, and 1 survived the 2nd year, while 88% of 64 seedlings planted in
1985 survived [81]. In Nebraska, individual purple coneflower plants and tallgrass prairie sod were
successfully relocated onto restoration sites [19].
Coal mine spoil materials in North Dakota have been successfully seeded with purple coneflower [15,16]. In a 2-year study conducted in southwestern North Dakota, directly seeded forbs, including purple coneflower, produced numerous seedlings in June following original planting [16]. In a separate study conducted in the northern Great Plains region, purple coneflower grown in greenhouse containers produced only a few seedlings after being transplanted, but displayed "exceptional" establishment characteristics and hearty growth in both years [15].
In South Dakota, artificially constructed earthen mounds on low, middle, and high productivity gradients were monitored to determine species richness and yield on a spatial scale. Purple coneflower was found on greater than 35% of the mounds located in each topographic gradient, indicating its ability to respond to disturbances and recolonize sites in which soil degradation has occurred [104].
Eddleman [31] discusses the viability of purple coneflower seeds for reclamation in southeastern
Montana. Age of seed, temperatures, stratification, and planting seasons are addressed as factors
in success rates. Albrecht and Smith-Jochum [1] discuss methods used in germination and establishment
of purple coneflower, including raised beds, soil pH, light availability, precipitation and
temperature.
OTHER USES:
Medicinal: Various Native American tribes harvest purple coneflower for a wide
range of applications. It is often used in the treatment of snakebite wounds
[3,37,40,54,59,87] in addition to oral ailments [37,40,54,59] and various
infections [35]. Purple coneflower has both antibiotic and antiviral attributes
[1] and can be used to augment immune systems [74].
Given the chemical heterogeneity and lack of standardized procedures for
preparation, health care researchers have found it difficult to assess the effectiveness
of purple coneflower [71]. Adverse effects stemming from the use of various Echinacea species
have been reported to the US Food and Drug Administration [101], and the importance of
standardizing preparation methods has been addressed [12].
OTHER MANAGEMENT CONSIDERATIONS:
Biological:
Wild and commercially-grown populations of purple coneflower are subject to interference from
nonnative plants and a variety of diseases. Wild populations in the oak savannahs of southeastern
Kansas were reduced after an invasion of sericea lespedeza (Lespedeza cuneata) [34]. In
Theodore Roosevelt National Park in southwestern North Dakota, purple coneflower was eliminated
by an infestation of leafy spurge (Euphorbia esula) [24]. In Alberta, commercial populations
have been infested with aster yellows [26], sclerotinia blight (Sclerotinia sclerotiorum)
[109], sclerotinia stem rot and botrytis blight [27].
Extracts from purple coneflower plants have been used to manage populations of both grain beetles [74] and yellow mealworms [53].
Pale echinacea (Echinacea pallida) has been shown to be highly aggressive and can outcompete purple coneflower whose dry weight and leaf area are considerably less [96].
Commercial Harvest: There are potential harvesting pressures on natural stocks of purple coneflower with renewed interest in its use as a medicinal plant [59]. Commercial production of purple coneflower is discussed in [7,20,29,50,52,82,110].
1. Albrecht, Mary Lewnes; Smith-Jochum, Christine. [n.d.]. Germination and establishment of Echinacea spp. (Compositae). Wildflower: Journal of the National Wildflower Research Center. 3(2): 6-11. [17083]
2. Anderson, Elizabeth S. 1992. Reconstructed prairie as an educational tool. In: Smith, Daryl D.; Jacobs, Carol A., eds. Recapturing a vanishing heritage: Proceedings, 12th North American prairie conference; 1990 August 5-9; Cedar Falls, IA. Cedar Falls, IA: University of Northern Iowa: 209-211. [24742]
3. Anon. 1993. Wildflower notebook. Wildflower. 10(3): 4. [20976]
4. Archer, Steven R. 1983. Plant community structure, competitive interactions and water relations as influenced by herbivores. Fort Collins, CO: Colorado State University. 114 p. Dissertation. [338]
5. Arno, Stephen F. 2000. Fire in western forest ecosystems. In: Brown, James K.; Smith, Jane Kapler, eds. Wildland fire in ecosystems: Effects of fire on flora. Gen. Tech. Rep. RMRS-GTR-42-vol. 2. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 97-120. [36984]
6. Baisan, Christopher H.; Swetnam, Thomas W. 1990. Fire history on a desert mountain range: Rincon Mountain Wilderness, Arizona, U.S.A. Canadian Journal of Forest Research. 20: 1559-1569. [14986]
7. Bantle, Myles; Carrier, D. Julie; Crowe, Trever. 2000. Development of guidelines for harvesting Echinacea angustifolia roots. Final Report: ADF Project 19990067. Regina, SK: Saskatchewan Agriculture and Foods, Agriculture Development Fund. 122 p. [49093]
8. Bare, Janet E. 1979. Wildflowers and weeds of Kansas. Lawrence, KS: The Regents Press of Kansas. 509 p. [3801]
9. Baskauf, Carol J. 2001. Examining rarity through comparisons with widespread congeners: a genetic and ecophysiological example from limestone and glade endemics. Castanea. 66(1-2): 126-133. [49190]
10. Baskin, Carol C.; Baskin, Jerry M.; Hoffman, George R. 1992. Seed dormancy in the prairie forb Echinacea angustifolia var. angustifolia (Asteraceae): afterripening pattern during cold stratification. International Journal of Plant Science. 15(3): 239-243. [19443]
11. Baskin, Jerry M.; Baskin, Carol C. 1978. Plant ecology of cedar glades in the Big Barren region of Kentucky. Rhodora. 80: 545-557. [45322]
12. Bauer, Rudolf. 1999. Chemistry, analysis and immunological investigations of Echinacea phytopharmaceuticals. In: Wagner, H., ed. Immunomodulatory agents from plants. Basil, Switzerland: Birkhauser Verlag: 41-88. [49076]
13. Bernard, Stephen R.; Brown, Kenneth F. 1977. Distribution of mammals, reptiles, and amphibians by BLM physiographic regions and A.W. Kuchler's associations for the eleven western states. Tech. Note 301. Denver, CO: U.S. Department of the Interior, Bureau of Land Management. 169 p. [434]
14. Binns, Shannon E.; Arnason, John T.; Baum, Bernard R. 2002. Phytochemical variation within populations of Echinacea angustifolia (Asteraceae). Biochemical Systematics and Ecology. 30(9): 837-854. [49203]
15. Bjugstad, Ardell J.; Whitman, Warren C. 1982. Perennial forbs for wildlife habitat restoration on mined lands in the northern Great Plains. In: Proceedings, 62nd annual conference of the Western Association of Fish and Wildlife Agencies; 1982 July 19-22; Las Vegas, Nevada: 257-271. [2932]
16. Bjugstad, Ardell J.; Whitman, Warren C. 1989. Promising native forbs for seeding on mine spoils. In: Walker, D. G.; Powter, C. B.; Pole, M. W., compilers. Proceedings of the conference: Reclamation, a global perspective; 1989 August 27-31; Calgary, AB. Edmonton, AB: Alberta Land Conservation and Reclamation Council: 255-262. [14354]
17. Boettcher, Judith F.; Bragg, Thomas B. 1989. Tallgrass prairie remnants of eastern Nebraska. In: Bragg, Thomas B.; Stubbendieck, James, eds. Prairie pioneers: ecology, history and culture: Proceedings, 11th North American prairie conference; 1988 August 7-11; Lincoln, NE. Lincoln, NE: University of Nebraska: 1-7. [14008]
18. Boyd, Chad S.; Bidwell, Terrence G. 2002. Effects of prescribed fire on shinnery oak (Quercus havardii) plant communities in western Oklahoma. Restoration Ecology. 10(2): 324-333. [42260]
19. Bragg, Thomas B. 1988. Prairie transplants: preserving ecological diversity. In: Davis, Arnold; Stanford, Geoffrey, eds. The prairie: roots of our culture; foundation of our economy: Proceedings, 10th North American prairie conference; 1986 June 22-26; Denton, TX. Dallas, TX: Native Prairie Association of Texas: 09.07: 1-6. [25608]
20. Bragg, Thomas B.; Sutherland, David M. 1989. Establishing warm-season grasses and forbs using herbicides and mowing. In: Bragg, Thomas B.; Stubbendieck, James, eds. Prairie pioneers: ecology, history and culture: Proceedings, 11th North American prairie conference; 1988 August 7-11; Lincoln, NE. Lincoln, NE: University of Nebraska: 81-89. [14023]
21. Bromley, Peter T. 1977. Aspects of the behavioural ecology and sociobiology of the pronghorn (Antilocapra americana). Calgary, AB: University of Calgary. 370 p. Dissertation. [8088]
22. Brown, H. Ray. 1943. Growth and seed yields of native prairie plants in various habitats of the mixed-prairie. Transactions, Kansas Academy of Science. 46: 87-99. [26146]
23. Buell, Murray F.; Facey, Vera. 1960. Forest-prairie transition west of Itasca Park, Minnesota. Bulletin of the Torrey Botanical Club. 87(1): 46-58. [14171]
24. Butler, Jack L.; Cogan, Daniel R. 2004. Leafy spurge effects on patterns of plant species richness. Journal of Range Management. 57(3): 305-311. [49818]
25. Callow, J. Michael; Kantrud, Harold A.; Higgins, Kenneth F. 1992. First flowering dates and flowering periods of prairie plants at Woodworth, North Dakota. Prairie Naturalist. 24(2): 57-64. [20450]
26. Chang, K. F.; Howard, R. J.; Blade, S. F.; Hwang, S. F. 2000. Survey of aster yellow of Echinacea in Alberta in 1999. Canadian Plant Disease Survey. Ottawa: Agriculture Canada, Research Branch. 80: 88-89. [49064]
27. Chang, K. F.; Howard, R. J.; Hwang, S. F.; Blade, S. F. 1999. Diseases of Echinacea in Alberta in 1998. Canadian Plant Disease Survey. Ottawa: Agriculture Canada, Research Branch. 79: 109-111. [49069]
28. Clambey, Gary K. 1992. Ecological aspects of the Knife River Indian Villages National Historic Site, west-central North Dakota. In: Smith, Daryl D.; Jacobs, Carol A., eds. Recapturing a vanishing heritage: Proceedings, 12th North American prairie conference; 1990 August 5-9; Cedar Falls, IA. Cedar Falls, IA: University of Northern Iowa: 75-78. [24719]
29. Dickerson, John A.; Longren, Warren G.; Hadle, Edith K. 1981. Native forb seed production. In: Stuckey, Ronald L.; Reese, Karen J., eds. The prairie peninsula--in the "shadow" of Transeau: Proceedings, 6th North American prairie conference; 1978 August 12-17; Columbus, OH. Ohio Biological Survey Biological Notes No. 15. Columbus, OH: Ohio State University, College of Biological Sciences: 218-222. [3431]
30. Dorn, Robert D. 1977. Flora of the Black Hills. [Place of publication unknown]: Robert D. Dorn and Jane L. Dorn. 377 p. [820]
31. Eddleman, Lee E. 1977. Indigenous plants of southeastern Montana. I. Viability and suitability for reclamation in the Fort Union Basin. Special Publication 4. Missoula, MT: University of Montana, School of Forestry, Montana Forest and Conservation Experiment Station. 122 p. [42440]
32. Eddleman, Lee E. 1979. Regeneration strategies of mixed-prairie plants. In: Goodin, J. R.; Northington, D. K., eds. Arid land plant resources: Proceedings of the international arid lands conference on plant resources; 1979 July; Lubbock, TX. Lubbock, TX: Texas Tech University, International Center for Arid and Semi-Arid Land Studies: 684-698. [845]
33. Eddy, Thomas A. 1992. The role of prairie road borders as refugia for herbaceous plants in the central Flint Hills grazing region of Kansas. In: Smith, Daryl D.; Jacobs, Carol A., eds. Recapturing a vanishing heritage: Proceedings, 12th North American prairie conference; 1990 August 5-9; Cedar Falls, IA. Cedar Falls, IA: University of Northern Iowa: 161-163. [24735]
34. Eddy, Thomas A.; Moore, Cindy M. 1998. Effects of sericea lespedeza (Lespedeza cuneata (Dumont) G. Don) invasion on oak savannas in Kansas. Transactions, Wisconsin Academy of Sciences, Arts and Letters. 86: 57-62. [45567]
35. Emmendorffer, Andreas C.; Wagner, Hildebert; Lohmann-Matthes, Marie-Luise. 1999. Immunologically active polysaccharides from Echinacea purpurea plant and cell cultures. In: Wagner, H., ed. Immunomodulatory agents from plants. Basil, Switzerland: Birkhauser Verlag: 89-104. [49077]
36. Englund, Judy Voigt; Meyer, William J. 1986. The impact of deer on 24 species of prairie forbs. In: Clambey, Gary K.; Pemble, Richard H., eds. The prairie: past, present and future: Proceedings, 9th North American prairie conference; 1984 July 29 - August 1; Moorhead, MN. Fargo, ND: Tri-College University Center for Environmental Studies: 210-212. [3575]
37. Ernst, E.; Stevinson, C. 1999. New data on old herbal remedies. Perfusion. 12(5): 192-194. [49180]
38. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. [905]
39. Fertig, Walter, compiler. 2001. The potential vascular plant flora of Devils Tower National Monument, [Online]. In: Wyoming Natural Diversity Database, University of Wyoming (Producer). Available: http://uwadmnweb.uwyo.edu/wyndd/Reports/pdf_fertig/Fertig_01_DevilsTower_PlantList.pdf [2005, April 29]. [43137]
40. Flannery, Michael A. 2001. From rudbeckia to echinacea: the emergence of the purple coneflower in modern therapeutics. In: HerbalGram 51. Austin, TX: American Botanical Council and the Herb Research Foundation: 29-33. [49053]
41. Flora of North America Association. 2004. Flora of North America: The flora. [Online]. Flora of North America Association (Producer). Available: http://www.fna.org/FNA. [36990]
42. Gao, Yong-Ping; Zheng, Guo-Hua; Gusta, Lawrence V. 1998. Potassium hydroxide improves seed germination and emergence in five native plant species. HortScience. 33(2): 274-276. [49143]
43. Garrison, George A.; Bjugstad, Ardell J.; Duncan, Don A.; Lewis, Mont E.; Smith, Dixie R. 1977. Vegetation and environmental features of forest and range ecosystems. Agric. Handb. 475. Washington, DC: U.S. Department of Agriculture, Forest Service. 68 p. [998]
44. Gartner, F. Robert. 1977. Ecological changes on pine grassland burned in fall and spring. Final Report Contract No. PX 120051027, U.S. Department of the Interior National Park Service, Rocky Mountain Regional Office. Rapid City, SD: South Dakota State University, Agricultural Research and Extension Center. 35 p. [1001]
45. Great Plains Flora Association. 1986. Flora of the Great Plains. Lawrence, KS: University Press of Kansas. 1392 p. [1603]
46. Guyette, Richard; McGinnes, E. A., Jr. 1982. Fire history of an Ozark glade in Missouri. Transactions, Missouri Academy of Science. 16: 85-93. [5170]
47. Harbage, James F. 2001. Micropropagation of Echinacea angustifolia, E. pallida, and E. purpurea from stem and seed explants. HortScience. 36(2): 360-364. [49145]
48. Higgins, Jeremy J.; Larson, Gary E.; Higgins, Kenneth F. 2001. Floristic comparisons of tallgrass prairie remnants managed by different land stewardships in eastern South Dakota. In: Bernstein, Neil P.; Ostrander, Laura J., eds. Seeds for the future; roots of the past: Proceedings of the 17th North American prairie conference; 2000 July 16-20; Mason City, IA. Mason City, IA: North Iowa Community College: 21-31. [46489]
49. Hipps, Carol Bishop. 1988. Purple coneflower. Horticulture. August: 46-49. [15616]
50. Holden, D. J.; Ellis, B. E.; Chen, C. H. 1978. Cloning native prairie plants by tissue culture. In: Glenn-Lewin, David C.; Landers, Roger Q., Jr., eds. Proceedings, 5th Midwest prairie conference; 1976 August 22-24; Ames, IA. Ames, IA: Iowa State University: 92-95. [3355]
51. Hu, Chun; Kitts, David D. 2000. Studies on the antioxidant activity of Echinacea root extract. Journal of Agriculture & Food Chemistry. 48(5): 1466-1472. [49202]
52. Izmailow, Romana; Pajak, Maria. 2002. Fertility of Echinacea angustifolia Moench and Linum usitatissimum L. after herbicide treatment. Breeding Research on Aromatic and Medicinal Plants. 9(2-3): 65-70. [49227]
53. Jacobson, Martin; Redfern, Robert E.; Mills, Giles D., Jr. 1975. Naturally occurring insect growth regulators. II. Screening of insect and plant extracts as insect juvenile hormone mimics. Lloydia. 38(6): 455-472. [49056]
54. Johnson, James R.; Nichols, James T. 1970. Plants of South Dakota grasslands: A photographic study. Bull. 566. Brookings, SD: South Dakota State University, Agricultural Experiment Station. 163 p. [18500]
55. Jones, Stanley D.; Wipff, Joseph K.; Montgomery, Paul M. 1997. Vascular plants of Texas. Austin, TX: University of Texas Press. 404 p. [28762]
56. Kapteyn, J.; Goldsbrough, P. B.; Simon, J. E. 2002. Genetic relationships and diversity of commercially relevant Echinacea species. Theoretical Applied Genetics. 105(2/3): 369-376. [49174]
57. Kartesz, John T.; Meacham, Christopher A. 1999. Synthesis of the North American flora (Windows Version 1.0), [CD-ROM]. Available: North Carolina Botanical Garden. In cooperation with the Nature Conservancy, Natural Resources Conservation Service, and U.S. Fish and Wildlife Service [2001, January 16]. [36715]
58. Kaul, Robert B. 2005. [Email to Amy Groen]. March 10. Information request for Echinacea angustifolia. Lincoln, NE: University of Nebraska, Bessey Herbarium. [52868]
59. Kindscher, Kelly. 1989. Ethnobotany of purple coneflower (Echinacea angustifolia, Asteraceae) and other Echinacea species. Economic Botany. 43(4): 498-507. [15615]
60. Kindscher, Kelly. 2005. [Email to Amy Groen]. March 4. Information request for Echinacea angustifolia. Lawrence, KS: University of Kansas, Biological Survey. [52866]
61. Kucera, Clair L. 1981. Grasslands and fire. In: Mooney, H. A.; Bonnicksen, T. M.; Christensen, N. L.; [and others], technical coordinators. Fire regimes and ecosystem properties: Proceedings of the conference; 1978 December 11-15; Honolulu, HI. Gen. Tech. Rep. WO-26. Washington, DC: U.S. Department of Agriculture, Forest Service: 90-111. [4389]
62. Kuchler, A. W. 1964. United States [Potential natural vegetation of the conterminous United States]. Special Publication No. 36. New York: American Geographical Society. 1:3,168,000; colored. [3455]
63. Lacey, John; Mosley, John. 2002. 250 plants for range contests in Montana. MONTGUIDE MT198402 AG 6/2002. Range E-2 (Misc.). Bozeman, MT: Montana State University, Extension Service. 4 p. [43671]
64. Lakshmanan, Prakash; Danesh, Majid; Taji, Acram. 1998. Production of four commercially cultivated Echinacea species by different methods of in vitro regeneration. Journal of Horticultural Science & Biotechnology. 77(2): 158-163. [49181]
65. Lauver, Chris L.; Kindscher, Kelly; Faber-Langendoen, Don; Schneider, Rick. 1999. A classification of the natural vegetation of Kansas. The Southwestern Naturalist. 44(4): 421-443. [38847]
66. Laven, R. D.; Omi, P. N.; Wyant, J. G.; Pinkerton, A. S. 1980. Interpretation of fire scar data from a ponderosa pine ecosystem in the central Rocky Mountains, Colorado. In: Stokes, Marvin A.; Dieterich, John H., technical coordinators. Proceedings of the fire history workshop; 1980 October 20-24; Tucson, AZ. Gen. Tech. Rep. RM-81. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station: 46-49. [7183]
67. Lippert, Robert D.; Hopkins, Harold H. 1950. Study of viable seeds in various habitats in mixed prairie. Transactions of the Kansas Academy of Science. 53(3): 355-364. [1461]
68. Mazza, G.; Cottrell T. 1999. Volatile components of roots, stems, leaves, and flowers of Echinacea species. Journal of Agriculture and Food Chemistry. 47(8): 3081-3085. [49221]
69. McAllister, Christine A.; Knapp, Alan K.; Maragni, Laura A. 1998. Is leaf-level photosynthesis related to plant success in a highly productive grassland? Oecologia. 117(1-2): 40-46. [33085]
70. McGregor, Ronald L. 1968. The taxonomy of the genus Echinacea (Compositae). University of Kansas Science Bulletin. 48(4): 113-142. [15614]
71. Melchart, Dieter; Linde, Klaus. 1999. Clinical investigations of Echinacea phytopharmaceuticals. In: Wagner, H., ed. Immunomodulatory agents from plants. Basil, Switzerland: Birkhauser Verlag: 105-118. [49090]
72. Missouri Department of Transportation. 2001. Endangered species checklist (flowering plants), [Online]. Available: http://www.conservation.state.mo.us/nathis/endangered/checklst [2002, February 22]. [40937]
73. Mohlenbrock, Robert H. 1993. Simpson Township Barrens, Illinois. Natural History. 102(4): 24-27. [20449]
74. Moore, Michael. 1989. Medicinal plants of the desert and canyon West. Santa Fe, NM: Museum of New Mexico Press. 184 p. [25027]
75. Nagel, Harold G. 1995. Vegetative changes during 17 years of succession on Willa Cather Prairie in Nebraska. In: Hartnett, David C., ed. Prairie biodiversity: Proceedings, 14th North American prairie conference; 1994 July 12-16; Manhattan, KS. Manhattan, KS: Kansas State University: 25-30. [28223]
76. Neuhauser, Claudia; Andow, D. A.; Heimpel, George E.; May, Georgiana; Shaw, Ruth G.; Wagenius, Stuart. 2003. Community genetics: expanding the synthesis of ecology and genetics. Ecology. 84(3): 545-558. [49200]
77. Olson, Wendell W. 1975. Effects of controlled burning on grassland within the Tewaukon National Wildlife Refuge. Fargo, ND: North Dakota University of Agriculture and Applied Science. 137 p. Thesis. [15252]
78. Owens, D. W.; Call, C. A. 1985. Germination characteristics of Helianthus maximilianai Schrad. and Simsia calva (Engelm. & Gray) Gray. Journal of Range Management. 38(4): 336-339. [22005]
79. Paysen, Timothy E.; Ansley, R. James; Brown, James K.; [and others]. 2000. Fire in western shrubland, woodland, and grassland ecosystems. In: Brown, James K.; Smith, Jane Kapler, eds. Wildland fire in ecosystems: Effects of fire on flora. Gen. Tech. Rep. RMRS-GTR-42-volume 2. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 121-159. [36978]
80. Piper, Jon K.; Gernes, Mark C. 1989. Vegetation dynamics of three tallgrass prairie sites. In: Bragg, Thomas B.; Stubbendieck, James, eds. Prairie pioneers: ecology, history and culture: Proceedings, 11th North American prairie conference; 1988 August 7-11; Lincoln, NE. Lincoln, NE: University of Nebraska: 9-14. [14011]
81. Platt, Dwight R. 1988. Development and survival of plants in a prairie reconstruction at Kauffman Museum in south central Kansas. In: Davis, Arnold; Stanford, Geoffrey, eds. The prairie: roots of our culture; foundation of our economy: Proceedings, 10th North American prairie conference; 1986 June 22-26; Denton, TX. Dallas, TX: Native Prairie Association of Texas: 09.02: 1-5. [25603]
82. Powell, Erin E.; Carrier, Danielle Julie; Crowe, Trever G.; Bantle, Myles R. L. 2001. Echinacoside and alkamide distribution in Echinacea angustifolia root: root depth and growing condition. Journal of Nutraceuticals, Functional and Medical Foods. 3(3): 95-106. [49173]
83. Quinnild, Clayton L.; Cosby, Hugh E. 1958. Relicts of climax vegetation on two mesas in western North Dakota. Ecology. 39(1): 29-32. [1925]
84. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. [2843]
85. Rothenberger, Steven J. 1995. Plant community analysis of Schultz Prairie, Webster County, Nebraska. In: Hartnett, David C., ed. Prairie biodiversity: Proceedings, 14th North American prairie conference; 1994 July 12-16; Manhattan, KS. Manhattan, KS: Kansas State University: 35-41. [28225]
86. Rowe, J. S. 1969. Lightning fires in Saskatchewan grassland. Canadian Field-Naturalist. 83: 317-324. [6266]
87. Santich, Rob; Davidson, Helga. 2002. Medicinal and food plants of the Navajo and Lakota people. Australian Journal of Medical Herbalism. 14(3): 122-126. [49197]
88. Sari, Ali O.; Morales, Mario R.; Simon, James E. 2001. Ethephon can overcome seed dormancy and improve seed germination in purple coneflower species Echinacea angustifolia and E. pallida. HortTechnology. 11(2): 202-205. [49171]
89. Sarvis, J. T. 1941. Grazing investigations on the Northern Great Plains. Bull. 307. Fargo, ND: North Dakota Experiment Station. 110 p. In cooperation with: U.S. Department of Agriculture, Northern Great Plains Field Station. [10853]
90. Schlicht, Dennis W.; Orwig, Timothy T. 1992. Sequential use of niche by prairie obligate skipper butterflies (Lepidoptera: Hesperidae) with implications for management. In: Smith, Daryl D.; Jacobs, Carol A., eds. Recapturing a vanishing heritage: Proceedings, 12th North American prairie conference; 1990 August 5-9; Cedar Falls, IA. Cedar Falls, IA: University of Northern Iowa: 137-139. [24730]
91. Schulthess, Brigitte H.; Giger, Eva; Baumann, Thomas, W. 1991. Echinacea: anatomy, phytochemical pattern, and germination of the achene. Planta Medica. 57(4): 384-388. [49230]
92. Schulz, Hartwig; Pfeffer, Sven; Quilitzsch, Rolf; Steuer, Boris; Reif, Klaus. 2002. Rapid and non-destructive determination of the echinacoside content in Echinacea roots by ATR-IR and NIR spectroscopy. Planta Medica. 68(10): 926-929. [49201]
93. Shalaby, A. S.; Agina, E. A.; El-Gengaihi, S. E.; El-Khayat, A. S.; Hindawy, S. F. 1997. Response of Echinacea to some agricultural practices. Journal of Herbs, Spices & Medicinal Plants. 4(4): 59-67. [49225]
94. Shiflet, Thomas N., ed. 1994. Rangeland cover types of the United States. Denver, CO: Society for Range Management. 152 p. [23362]
95. Smith-Jochum, C. C.; Albrecht, M. L. 1987. Field establishment of three Echinacea species for commercial production. Acta Horticulturae. 208: 115-120. [49175]
96. Snyder, Kristin M.; Baskin, Jerry M.; Baskin, Carol C. 1994. Comparative ecology of the narrow endemic Echinacea tennesseensis and two geographically widespread congeners: relative competitive ability and growth characteristics. International Journal of Plant Sciences. 155(1): 57-65. [49219]
97. Sorensen, J. T.; Holden, D. J. 1974. Germination of native prairie forb seeds. Journal of Range Management. 27(2): 123-126. [15617]
98. Steigman, Kenneth L.; Ovenden, Lynn. 1988. Transplanting tallgrass prairie with a sodcutter. In: Davis, Arnold; Stanford, Geoffrey, eds. The prairie: roots of our culture; foundation of our economy: Proceedings, 10th North American prairie conference; 1986 June 22-26; Denton, TX. Dallas, TX: Native Prairie Association of Texas: 09.01: 1-2. [25602]
99. Stickney, Peter F. 1989. FEIS postfire regeneration workshop--April 12: Seral origin of species comprising secondary plant succession in Northern Rocky Mountain forests. 10 p. Unpublished draft on file at: U.S. Department of Agriculture, Forest Service, Intermountain Research Station, Fire Sciences Laboratory, Missoula, MT. [20090]
100. Stockrahm, Donna M. Bruns; Olson, Theresa Ebbenga; Harper, Elizabeth K. 1993. Plant species in black-tailed prairie dog towns in Billings County, North Dakota. Prairie Naturalist. 25(2): 173-183. [23167]
101. Thomas, Paul R. 2001. Echinacea: a natural remedy for the common cold and flu? Nutrition Today. 36(5): 249-253. [49223]
102. Tolstead, W. L. 1947. Woodlands in northwestern Nebraska. Ecology. 28(2): 180-188. [18407]
103. U.S. Department of Agriculture, National Resource Conservation Service. 2005. PLANTS database (2004), [Online]. Available: https://plants.usda.gov /. [34262]
104. Umbanhowar, Charles E., Jr. 1995. Revegetation of earthen mounds along a topographic-productivity gradient in a northern mixed prairie. Journal of Vegetation Science. 6(5): 637-646. [27167]
105. Viles, A. L.; Reese, R. N. 1996. Allelopathic potential of Echinacea angustifolia D.C. Environmental and Experimental Botany. 36(1): 39-43. [49187]
106. Wade, Dale D.; Brock, Brent L.; Brose, Patrick H.; [and others]. 2000. Fire in eastern ecosystems. In: Brown, James K.; Smith, Jane Kapler, eds. Wildland fire in ecosystems: Effects of fire on flora. Gen. Tech. Rep. RMRS-GTR-42-vol. 2. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 53-96. [36983]
107. Wagenius, S. 2000. Performance of a prairie mating system in fragmented habitat: self-compatibility and limited pollen dispersal in Echinacea angustifolia. St. Paul, MN: University of Minnesota. Dissertation. [52747]
108. Wagenius, Stuart; Shaw, Ruth. 2002. Recruitment and fire: how prescribed burns affect seedling recruitment in the native prairie plant Echinacea angustifolia. In: Annual meeting of the Ecological Society of America; 2002 August 4-9; Tucson, AZ: Abstract. Available online: http://abstracts.co.allenpress.com/pweb/esa2002/document/?ID=17706 [2005, May 17]. [52870]
109. Wang, H.; Chang, K. F.; Hwang, S. F.; Turnbull, G. D.; Howard, R. J. 2000. Effects of root inoculation and fungicide soil drenches on sclerotinia blight of coneflower. Canadian Journal of Plant Science. 80(4): 909-915. [49192]
110. Wiley, Moira K. 2001. Echinacea--reaping herbal profits. Ag Ventures. 5(4): 11-13. [49054]
111. Wilson, Gail W. T.; Hartnett, David C. 1998. Interspecific variation in plant responses to mycorrhizal colonization in tallgrass prairie. American Journal of Botany. 85(12): 1732-1738. [30311]
112. Wolf, Hans-Thomas; Zundorf, Ilse; Winckler, Thomas; Bauer, Rudolph; Dingermann, Theodor. 1999. Characterization of Echinacea species and detection of possible adulterations by RAPD analysis. Planta Medica. 65(8): 773-774. [49182]
113. Wright, Henry A.; Bailey, Arthur W. 1982. Fire ecology: United States and southern Canada. New York: John Wiley & Sons. 501 p. [2620]
114. Zimmerman, Gregory M. 1981. Effects of fire upon selected plant communities in the Little Missouri Badlands. Fargo, ND: North Dakota State University. 60 p. Thesis. [5121]