Fire Effects Information System (FEIS)

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INTRODUCTORY

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].

DISTRIBUTION AND OCCURRENCE

• GENERAL DISTRIBUTION
• ECOSYSTEMS
• STATES/PROVINCES
• BLM PHYSIOGRAPHIC REGIONS
• KUCHLER PLANT ASSOCIATIONS
• SAF COVER TYPES
• SRM (RANGELAND) COVER TYPES
• HABITAT TYPES AND PLANT COMMUNITIES

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].

BOTANICAL AND ECOLOGICAL CHARACTERISTICS

• GENERAL BOTANICAL CHARACTERISTICS
• RAUNKIAER LIFE FORM
• REGENERATION PROCESSES
• SITE CHARACTERISTICS
• SUCCESSIONAL STATUS
• SEASONAL DEVELOPMENT

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.

FIRE ECOLOGY

• FIRE ECOLOGY OR ADAPTATIONS
• POSTFIRE REGENERATION STRATEGY

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".

FIRE EFFECTS

• IMMEDIATE FIRE EFFECT ON PLANT
• DISCUSSION AND QUALIFICATION OF FIRE EFFECT
• PLANT RESPONSE TO FIRE
• DISCUSSION AND QUALIFICATION OF PLANT RESPONSE
• FIRE MANAGEMENT CONSIDERATIONS

MANAGEMENT CONSIDERATIONS

• IMPORTANCE TO LIVESTOCK AND WILDLIFE
• VALUE FOR REHABILITATION OF DISTURBED SITES
• OTHER USES
• OTHER MANAGEMENT CONSIDERATIONS

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].

Echinacea angustifolia: References

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