Symphyotrichum laeve, smooth blue aster
Sullivan, Janet. 1992. Symphyotrichum laeve, smooth blue aster. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: https://research.fs.usda.gov/feis/species-reviews/symlae
| Abbreviation | Common Name | Scientific Name | Classification | Status |
|---|---|---|---|---|
| Plants | ||||
| SYMLAE | smooth blue aster | Symphyotrichum laeve | Life Form: Plants/Forb Kingdom: Plantae Class: Dicot Order: Asterales Family: Asteraceae Genus: Symphiotrichum | Fed. Protected: No Nativity: Native Invasiveness: Noninvasive |
Taxonomy
The accepted scientific name for smooth blue aster is Symphyotrichum laeve (L.) A.& D. Löve. Recognized varieties are as follows [55,56]:
- Symphyotrichum laeve var. concinnus (Willd.) Nesom
- Symphyotrichum laeve var. geyeri (Gray) Nesom
- Symphyotrichum laeve var. laeve
- Symphyotrichum laeve var. purpuratus (Nees) Nesom
Synonyms
for Symphyotrichum laeve
- Aster laevis L. [21,22,40,53]
for Symphyotrichum laeve var. concinnus (Willd.) Nesom [55,56]
- Aster laevis var. concinnus (Willd.) House [21,22,40,53]
for Symphyotrichum laeve var. geyeri (Gray) Nesom [55,56]
- Aster laevis var. geyeri Gray [21,22,40,53]
- Aster laevis var. guadalupensis A.G. Jones [21,22,40,53]
for Symphyotrichum laeve var. laeve [55,56]
- Aster laevis var. laevis [21,22,40,53]
for Symphyotrichum laeve var. purpuratus (Nees) Nesom [55,56]
- Aster laevis var. purpuratus [21,22,40,53]
Other Common Names
purple aster, smooth blue American-aster, smooth aster
General Distribution
Smooth blue aster is widely distributed in the United States and Canada from the Atlantic Coast to the eastern slopes of the Cascade Range, south to New Mexico, Texas, and Georgia [19,40,43]. In eastern North America, S. l. var. laeve is the most common. This variety intergrades in the Great Plains with S. l. var. geyeri. Symphyotrichum laeve var. geyeri's distribution continues through the mountain states to Yukon Territory and British Columbia, eastern Washington and Oregon, south through Utah to New Mexico and Texas [19]. It is cultivated in Hawaii [54]. S. l. var. coccinnus occurs in Georgia, North Carolina, Tennessee, and Virginia [50].
States and Provinces
- United States: AL AZ CO CT DE GA HI ID IL IN IA KS KY LA ME MD MA MI MN MO MT NE NV NH NJ NM NY NC ND OH OK OR PA RI SC SD TN TX UT VT VA WA WV WI WY
- Canada: AB BC MB NB NF NS ON PE PQ SK YT
Site Characteristics
Smooth blue aster occurs on a wide variety of sites, including moist, sandy soil in woods, dry woods, and open areas, and mesic and dry-mesic prairies [30,40]. Cover and frequency of smooth blue aster is highest on sites with high light intensities, though it occurs on more shaded sites as well [41]. It usually sustains higher populations on wetter, more poorly drained glacial till soils in eastern Illinois and western Indiana [6]. In Michigan, however, Beaufait [4] reported that although smooth blue aster occurs on mesic and transitional sites, it is more likely to be encountered on the more xeric sites.
Elevation occurrence data from selected western states is as follows [12]:
| State | Elevation (ft) | Elevation (m) |
|---|---|---|
| Utah | 5,700–8,600 | 1,737–2,621 |
| Colorado | 5,000–9,300 | 1,524–2,835 |
| Wyoming | 3,700–7,600 | 1,128–2,316 |
| Montana | 2,300–6,000 | 701–1,829 |
Plant Communities
Smooth blue aster is a component of many types of plant associations, most notably of mixed prairie types such as needlegrass (Stipa comata, S. spartea)–blue grama (Bouteloua gracilis) and wheatgrass (Elymus lanceolatus, Pascopyrum smithii)–junegrass (Koeleria cristata) types [10].
Smooth blue aster is an understory dominant or a component in a number of quaking aspen (Populus tremuloides) community types, including a quaking aspen-Missouri gooseberry (Ribes missouriense)–roughleaf ricegrass (Oryzopsis asperifolia)–smooth blue aster community type [39]. It also occurs as an understory dominant in a quaking aspen–Bigelow ligularia (Ligularia bigelovii) community type [34]. Smooth blue aster is a leading dominant in a smooth blue aster-western yarrow (Achillea millefolium v. lanulosa) plant association found in openings in quaking aspen parklands [29].
Botanical Description
Smooth blue aster is a moderately tall (12 to 40 inches [30 -100 cm]) native perennial forb, with a stout rhizome and branching caudex. There are one to several erect stems. The fruit is a one-seeded achene [14,19,36].
Raunkiaer Life Form (Raunkiaer 1934)
- Hemicryptophyte
- Geophyte
Seasonal Development
Smooth blue aster blooms from August to October [11]. The lowermost leaves are early deciduous; the remaining leaves are dropped after frost top-kills the plant [19].
Regeneration Processes
Smooth blue aster reproduces well from seed. Seeds do not require either scarification or stratification [20,32]. Greenhouse germination trials showed that, without stratification, initial germination occurs at 7 days, and peak germination occurs at 20 days [32]. Seed banking is not apparent; soil samples collected in August (probably before seed release) contained no germinable smooth blue aster seeds [37].
Successional Status
Thirty years after study plots had been retired from heavy grazing, smooth blue aster was found only on the edges of the sites nearest undisturbed native prairie [18]. Smooth blue aster is found on roadsides and other previously disturbed areas but is probably not an initial colonizer.
Smooth blue aster is probably not tolerant of deep shade but will tolerate light or intermittent shade.
Immediate Fire Effects
Fire top-kills smooth blue aster.
Postfire Regeneration Strategy (Stickney 1989)
- Rhizomatous herb, rhizome in soil
- Ground residual colonizer (on-site, initial community)
- Secondary colonizer - off-site seed
Fire Adaptations
Smooth blue aster sprouts from the rhizome after being top-killed by fire. It occurs in a number of plant associations that have frequent fire regimes. Presumably, it is adapted to fire, though no specific information is available in the literature.
In general, forbs are more adversely affected by fires that occur later in the spring. Usually cover is reduced, while overall composition remains little affected. Forbs are much less affected by dormant-season fires than by spring fires [8].
Plant Response to Fire
Most reports on the effects of fire in communities occupied by smooth aster are inconclusive as to its response [1,17]. The number of leaves per individual plant increased following a late spring prescribed fire, with no change in the number of flowers or fruit per individual for either the early spring or late spring prescribed fires [27]. Prescribed spring fires had variable effects on flowering in smooth aster, depending on habitat. Flowering was inhibited on dry-mesic prairie site on an undisturbed south-facing slope and on a highly disturbed, level, mesic prairie site. Flowering was stimulated on sloping and level mesic undisturbed prairie sites [33]. Three years after a wildfire in jack pine (Pinus banksiana) stands, smooth blue aster was an important component of the regenerating plots. These sites had standing dead trees, which indicates that there was probably a substantial loss of crown shading [2].
Smooth blue aster was listed as a decreaser under an annual early spring burning regime, and also after a spring wildfire [3,44]. Scheiner [37] reported the presence of smooth blue aster on sites that had recently undergone prescribed burns, as well as on older postfire seral sites.
Fire Regimes
For fire regime information, search FEIS for this species by entering the species name or acronym on the home page and selecting “Fire Regime” as the publication type.
Fire Management Considerations
No entry.
Federal Status
None
Other Status
Information on state-level protected status of plants in the United States is available at Plants Database.
Importance to Wildlife and Livestock
White-tailed deer will graze smooth blue aster, selecting it over other available forbs [14].
Palatability and Nutritional Value
Smooth blue aster is palatable to white-tailed deer and livestock [14,47]. It is likely that it is palatable to other species as well, but documentation is not available.
Smooth blue aster has high nutritional value, decreasing with maturation. Nutritional values for aerial portions are as follows [7]:
| Stage of maturation | Digestible protein (%) | Cellulose (%) | Digestibility (%) |
|---|---|---|---|
| Leaf stage | 11.6 | 27.2 | 77.1 |
| Heading | 5.9 | 28.8 | 55.2 |
| Seed ripening | 5.2 | 31.2 | 61.8 |
Cover Value
No entry.
Value for Rehabilitation or Restoration of Disturbed Sites
Direct seeding of smooth blue aster was successful in establishing plants along highway margins for prairie restoration [32]. Smooth blue aster is recommended in seedings and plantings for rehabilitation or restoration of native mixed-grass and tallgrass prairies [31,32,49].
Other Uses
No entry.
Other Management Considerations
In a study of prairie regeneration in which herbicides were applied to control quackgrass (Agropyron repens), smooth blue aster failed to establish in plantings treated with either glyphosate or dichlobenil [49]. Picloram, tebuthiuron, and hexazinone all suppressed growth of smooth aster, either alone or in combination. Applied alone, 2,4,D-E did not suppress smooth blue aster growth [31].
Grazing by deer does not appear to affect survival of established plants or seedlings, as long as only the stem tips are removed. Most plants damaged by deer responded with vigorous growth the following season [14]. Weaver and Hansen [47] classify smooth blue aster as a decreaser under grazing.
Plants grown under nursery conditions had excellent rates of survival when planted in the field. Nursery stock was planted at a rate of 3.5 ounces of seed per 100 square feet (11 gm/sq m) and resulted in a harvest of 9.5 pounds of seed per 100 square feet (0.5 kg/sq m) [46].
Table A1— Forest and range ecosystems, Bureau of Land Management (BLM) physiographic regions, Kuchler plant associations, Society for American Foresters (SAF) forest cover types, and Society for Rangeland Management (SRM) rangeland cover types in which this species occurs.
Forest and Range Ecosystems (Garrison et al. 1977)
- FRES10 White - red - jack pine
- FRES12 Longleaf - slash pine
- FRES13 Loblolly - shortleaf pine
- FRES14 Oak - pine
- FRES15 Oak - hickory
- FRES18 Maple - beech - birch
- FRES19 Aspen - birch
- FRES21 Ponderosa pine
- FRES36 Mountain grasslands
- FRES38 Plains grasslands
- FRES39 Prairie
BLM Physiographic Regions (Bernard and Brown 1977)
- 2 Cascade Mountains
- 4 Sierra Mountains
- 5 Columbia Plateau
- 6 Upper Basin and Range
- 8 Northern Rocky Mountains
- 9 Middle Rocky Mountains
- 10 Wyoming Basin
- 11 Southern Rocky Mountains
- 12 Colorado Plateau
- 13 Rocky Mountain Piedmont
- 14 Great Plains
- 15 Black Hills Uplift
- 16 Upper Missouri Basin and Broken Lands
Kuchler Plant Associations (Kuchler 1964)
- K011 Western ponderosa forest
- K016 Eastern ponderosa forest
- K017 Black Hills pine forest
- K050 Fescue - wheatgrass
- K051 Wheatgrass - bluegrass
- K056 Wheatgrass - needlegrass shrubsteppe
- K063 Foothills prairie
- K064 Grama - needlegrass - wheatgrass
- K065 Grama - buffalograss
- K066 Wheatgrass - needlegrass
- K067 Wheatgrass - bluestem - needlegrass
- K068 Wheatgrass - grama - buffalograss
- K069 Bluestem - grama prairie
- K070 Sandsage - bluestem prairie
- K074 Bluestem prairie
- K075 Nebraska Sandhills prairie
- K081 Oak savanna
- K082 Mosaic of K074 and K100
- K084 Cross Timbers
- K095 Great Lakes pine forest
- K099 Maple - basswood forest
- K100 Oak - hickory forest
- K102 Beech - maple forest
- K103 Mixed mesophytic forest
- K104 Appalachian oak forest
- K106 Northern hardwoods
- K107 Northern hardwoods - fir forest
- K108 Northern hardwoods - spruce forest
- K109 Transition between K104 and K106
- K110 Northeastern oak - pine forest
- K111 Oak - hickory - pine forest
- K112 Southern mixed forest
SAF Cover Types (Eyre 1980)
- 1 Jack pine
- 14 Northern pin oak
- 15 Red pine
- 16 Aspen
- 18 Paper birch
- 19 Gray birch - red maple
- 20 White pine - northern red oak - red maple
- 21 Eastern white pine
- 25 Sugar maple - beech - yellow birch
- 26 Sugar maple - basswood
- 27 Sugar maple
- 42 Bur oak
- 44 Chestnut oak
- 46 Eastern redcedar
- 52 White oak - black oak - northern red oak
- 53 White oak
- 70 Longleaf pine
- 75 Shortleaf pine
- 78 Virginia pine - oak
- 79 Virginia pine
- 83 Longleaf pine - slash pine
- 84 Slash pine
- 237 Interior ponderosa pine
SRM Rangeland Cover Types (Shiflet 1994)
- No entry
1. Abrams, Marc D.; Dickmann, Donald I. 1984. Floristic composition before and after prescribed fire on a jack pine clear-cut site in northern lower Michigan. Canadian Journal of Forest Research. 14: 746-749. [7236]
2. Abrams, Marc D.; Sprugel, Douglas G.; Dickmann, Donald I. 1985. Multiple successional pathways on recently disturbed jack pine sites in Michigan. Forest Ecology and Management. 10: 31-48. [7237]
3. Anderson, Howard G.; Bailey, Arthur W. 1980. Effects of annual burning on grassland in the aspen parkland of east-central Alberta. Canadian Journal of Botany. 58: 985-996. [3499]
4. Beaufait, W. R.; Brown, R. T. 1962. Phytogeography of a representative outwash plain jack pine site. Papers of the Michigan Academy of Science, Arts & Letters. 47: 201-209. [7239]
5. 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]
6. Betz, Robert F.; Lamp, Herbert F. 1989. Species composition of old settler silt-loam prairies. 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: 33-39. [14016]
7. Bezeau, L. M.; Johnston, A. 1962. In vitro digestibility of range forage plants of the Festuca scabrella association. Canadian Journal of Plant Science. 42: 692-697. [441]
8. Bragg, Thomas B. 1991. Implications for long-term prairie management from seasonal burning of loess hill and tallgrass prairie. In: Nodvin, Stephen C.; Waldrop, Thomas A., eds. Fire and the environment: ecological and cultural perspectives: Proceedings of an international symposium; 1990 March 20-24; Knoxville, TN. Gen. Tech. Rep. SE-69. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southeastern Forest Experiment Station: 34-44. [16631]
9. Brown, Lauren. 1985. The Audubon Society nature guides: Grasslands. New York: Alfred A. Knopf, Inc. 606 p. [4561]
10. Coupland, Robert T. 1950. Ecology of mixed prairie in Canada. Ecological Monographs. 20(4): 271-315. [700]
11. Diekelmann, John; Howell, Evelyn A.; Harrington, John. 1986. An approach to residential landscaping with prairie. 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: 242-248. [3587]
12. Dittberner, Phillip L.; Olson, Michael R. 1983. The plant information network (PIN) data base: Colorado, Montana, North Dakota, Utah, and Wyoming. FWS/OBS-83/86. Washington, DC: U.S. Department of the Interior, Fish and Wildlife Service. 786 p. [806]
13. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. [905]
14. 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]
15. Fernald, Merritt Lyndon. 1950. Gray's manual of botany. [Corrections supplied by R. C. Rollins]. Portland, OR: Dioscorides Press. 1632 p. (Dudley, Theodore R., gen. ed.; Biosystematics, Floristic & Phylogeny Series; vol. 2) [14935]
16. Garrison, George A.; Bjugstad, Ardell J.; Duncan, Don A.; [and others]. 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]
17. Gibson, David J. 1989. Hulbert's study of factors effecting botanical composition of tallgrass prairie. 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: 115-133. [14029]
18. Glenn-Lewin, David C. 1980. The individualistic nature of plant community development. Vegetatio. 43: 141-146. [7857]
19. Great Plains Flora Association. 1986. Flora of the Great Plains. Lawrence, KS: University Press of Kansas. 1392 p. [1603]
20. Greene, H. C.; Curtis, J. T. 1950. Germination studies of Wisconsin prairie plants. The American Midland Naturalist. 43(1): 186-194. [4086]
21. Jones, Almut G. 1981. Aster laevis (Asteraceae) new for Texas, a significant range extension and a new variety. SIDA-Contributions to Botany. 9(2): 172-175. [20039]
22. Kartesz, John T.; Kartesz, Rosemarie. 1980. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. Volume II: The biota of North America. Chapel Hill, NC: The University of North Carolina Press; in confederation with Anne H. Lindsey and C. Richie Bell, North Carolina Botanical Garden. 500 p. [6954]
23. Kebart, Karen K.; Anderson, Roger C. 1987. Phenological and climatic patterns in three tallgrass prairies. The Southwestern Naturalist. 32(1): 29-37. [5438]
24. Kittredge, J., Jr. 1934. Evidence of the rate of forest succession on Star Island, Minnesota. Ecology. 15(1): 24-35. [10102]
25. Kuchler, A. W. 1964. Manual to accompany the map of potential vegetation of the conterminous United States. Special Publication No. 36. New York: American Geographical Society. 77 p. [1384]
26. Love, Askell; Love, Doris. 1954. Vegetation of a prairie marsh. Bulletin of the Torrey Botanical Club. 81(1): 16-34. [18103]
27. Lovell, David L.; Henderson, Richard A.; Howell, Evelyn A. 1983. The response of forb species to seasonal timing of prescribed burns in remnant Wisconsin prairies. In: Brewer, Richard, ed. Proceedings of the eighth North American prairie conference; 1982 August 1-4; Kalamazoo, MI. Kalamazoo, MI: Western Michigan University, Department of Biology: 11-15. [3115]
28. Lyon, L. Jack; Stickney, Peter F. 1976. Early vegetal succession following large northern Rocky Mountain wildfires. In: Proceedings, Tall Timbers fire ecology conference and Intermountain Fire Research Council fire and land management symposium; 1974 October 8-10; Missoula, MT. No. 14. Tallahassee, FL: Tall Timbers Research Station: 355-373. [1496]
29. Lynch, Daniel. 1955. Ecology of the aspen groveland in Glacier County, Montana. Ecological Monographs. 25(4): 321-344. [950]
30. Mohlenbrock, Robert H. 1986. (Revised edition). Guide to the vascular flora of Illinois. Carbondale, IL: Southern Illinois University Press. 507 p. [17383]
31. Moyer, J. R.; Smoliak, S. 1987. Shrubby cinquefoil control changes range forage production. Canadian Journal of Plant Science. 67: 727-734. [3894]
32. Nuzzo, Victoria. 1978. Propagation and planting of prairie forbs and grasses in southern Wisconsin. 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: 182-189. [3379]
33. Pemble, R. H.; Van Amburg, G. L.; Mattson, Lyle. 1981. Intraspecific variation in flowering activity following a spring burn on a northwestern Minnesota prairie. 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: 235-240. [3435]
34. Powell, David C. 1988. Aspen community types of the Pike and San Isabel National Forests in south-central Colorado. R2-ECOL-88-01. Denver, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Region. 254 p. [15285]
35. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. [2843]
36. Radford, Albert E.; Ahles, Harry E.; Bell, C. Ritchie. 1968. Manual of the vascular flora of the Carolinas. Chapel Hill, NC: The University of North Carolina Press. 1183 p. [7606]
37. Scheiner, Samuel M. 1988. The seed bank and above-ground vegetation in an upland pine-hardwood succession. Michigan Botanist. 27(4): 99-106. [12396]
38. Semple, John C.; Chmielewski, Jerry G.; Lane, Meredith A. 1989. Chromosome number determinations in fam. Compositae, tribe Astereae. 3. Additional counts and comments on generic limits and ancestral... Rhodora. 91(868): 296-314. [20038]
39. Severson, Kieth E.; Thilenius, John F. 1976. Classification of quaking aspen stands in the Black Hills and Bear Lodge Mountains. Res. Pap. RM-166. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station. 24 p. [2111]
40. Seymour, Frank Conkling. 1982. The flora of New England. 2d ed. Phytologia Memoirs 5. Plainfield, NJ: Harold N. Moldenke and Alma L. Moldenke. 611 p. [7604]
41. Shirley, Hardy L. 1932. Light intensity in relation to plant growth in a virgin Norway pine forest. Journal of Agricultural Research. 44: 227-244. [10360]
42. Stallard, Harvey. 1929. Secondary succession in the climax forest formations of northern Minnesota. Ecology. 10(4): 476-547. [3808]
43. Stubbendieck, James. 1988. Historical development of native vegetation on the Great Plains. In: Mitchell, John E, ed. Impacts of the Conservation Reserve Program in the Great Plains; 1987 September 16-18; Denver, CO. Gen. Tech. Rep. RM-158. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station: 21-28. [5142]
44. Swan, Frederick R., Jr. 1970. Post-fire response of four plant communities in south-central New York state. Ecology. 51(6): 1074-1082. [3446]
45. U.S. Department of Agriculture, Natural Resources Conservation Service. 2007. PLANTS Database, [Online]. Available: https://plants.usda.gov /. [34262]
46. Wallace, Virginia K.; Pequignot, Stewart; Yoder, William. 1986. The role of state forest nurseries in prairie plant propagation. In: Clambey, Gary K.; Pemble, Richard H., eds. The prairie: past, present and future: Proceedings of the ninth North American prairie conference; 1984 July 29 - August 1; Moorhead, MN. Fargo, ND: Tri-College University Center for Environmental Studies: 201-203. [3573]
47. Weaver, J. E.; Hansen, W. W. 1941. Native midwestern pastures; their origin, composition and degeneration. University of Nebraska Conservation Bulletin 22. 93 p. [20777]
48. Welsh, Stanley L.; Atwood, N. Duane; Goodrich, Sherel; Higgins, Larry C., eds. 1987. A Utah flora. The Great Basin Naturalist Memoir No. 9. Provo, UT: Brigham Young University. 894 p. [2944]
49. Woehler, Eugene E.; Martin, Mark A. 1978. Establishment of prairie grasses and forbs with the use of herbicides. 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: 131-138. [3367]
50. Wofford, B. Eugene. 1989. Guide to the vascular plants of the Blue Ridge. Athens, GA: The University of Georgia Press. 384 p. [12908]
51. U.S. Department of the Interior, Fish and Wildlife Service. 1993. 50 CFR Part 17: Plant taxa for listing as endangered or threatened species; notice of review--September 30, 1993. Federal Register. 58(188): 51144-51190. [23816]
52. U.S. Department of the Interior, National Biological Survey. [n.d.]. NP Flora [Data base]. Davis, CA: U.S. Department of the Interior, National Biological Survey. [23119]
53. Kartesz, John T. 1994. A synonymized checklist of the vascular flora of the United States, Canada, and Greenland. Volume II--thesaurus. 2nd ed. Portland, OR: Timber Press. 816 p. [23878]
54. St. John, Harold. 1973. List and summary of the flowering plants in the Hawaiian islands. Hong Kong: Cathay Press Limited. 519 p. [25354]