|© Br. Alfred Brousseau, Saint Mary's College|
|Gary A. Monroe @ USDA-NRCS PLANTS Database|
California redbud is a native , deciduous [35,44,72] shrub-tree [11,36,48,49,54,64]. It can appear as a tree with arching canopies that almost reach the ground or a considerably shorter, many-stemmed shrub [68,72]. Plants generally occur singly, but they may form thickets in riparian zones .
California redbud plants are commonly from 7 to 20 feet (2-5 m) tall [35,54,55,76]. The tallest California redbud on record is 29 feet (8.8 m) . The stems are clustered and erect [36,54,55] and predominantly leafless . During the 1st year of life, California redbud stems are covered in hairs . The inflorescence is a 2- to 5-flowered raceme . The flowers are 8 to 12 mm long [54,55] and appear before the leaves [20,40,76]. The seedpod is a flat legume from 2 to 4 inches (4-9 cm) long and 0.8 to 1 inch (2-2.5 cm) wide [54,55]. Each seedpod contains 7 seeds  from 3 to 4 mm in diameter [54,55]
California redbud is intermediately tolerant of flooding in semiarid riparian zones. Intermediately tolerant is defined as a species that "is able to survive flooding for periods between 1 to 3 months during the growing season. The root systems of these plants may produce few new roots or will be dormant during the flooded period" .RAUNKIAER  LIFE FORM:
Pollination: California redbud is pollinated by bumble bees and orchard mason bees [11,24,72].
Breeding system: The flowers of California redbud are dioecious .
California redbud produces abundant crops of legumes, but seed set is variable . Seed dispersal:
California redbud seeds are dispersed by wind, birds, and animals . Seed banking:
California redbud utilizes a seed bank . Germination:
J.S. Peterson @ USDA-NRCS PLANTS DATABASE
Seed production: California redbud produces abundant crops of legumes, but seed set is variable .
Seed dispersal: California redbud seeds are dispersed by wind, birds, and animals .
Seed banking: California redbud utilizes a seed bank .
Germination:California redbud seeds require scarification and stratification for germination [44,48,53]. The seeds are adapted to prolonged periods of dryness and cold due to an impervious seed coat and a dormant embryo [1,34,72].
There are no field studies of California redbud seed longevity to date (2006); however, California redbud seeds remained viable for 12 years or more when stored in a freezer at 5% to 9% humidity and 0°F (-18 °C) .
Seedling establishment/growth: California redbud seedlings have a "rapid" growth rate .
Asexual regeneration: California redbud may regenerate asexually by sprouting from boles damaged by fire .SITE CHARACTERISTICS:
In the foothills of northern California, California redbud occurs at low elevations on north-facing slopes or near seasonal water courses .
Climate: California redbud is light and drought tolerant [44,72]. In California chaparral sites, California redbud persists where the winters are cool and wet and the summers are hot and dry .
Elevation: The elevation ranges for California redbud in the 4 states where it occurs are presented in the table below:
|Arizona||4,000 to 6,000 feet [40,49]|
|California||400 to 5,000 feet [35,54,55]|
|Nevada||2,500 to 6,200 feet |
|Utah||2,168 to 4,053 feet [21,76]|
Soil: California redbud can tolerate a wide range of soils [68,72]. In California chaparral, California redbud is found on granitic soils .SUCCESSIONAL STATUS:
At Ellis Ranch, California, California redbud occurs on "early succession" burn sites [29,50]. California redbud is an important species in the late-seral conifer forest-chaparral association of northern California .SEASONAL DEVELOPMENT:
Fire regimes: Research literature on California redbud is primarily centered on its occurrence in California chaparral and oak woodlands. Both of these community types can have lightning-ignited fires and have long been affected by anthropogenic fire, starting with Native Americans [2,42,43]. Prior to European settlement, the western Mono, foothill Yokuts, and Miwok Native Americans of the central and southern Sierra Nevada foothills set autumn fires at intervals of 1 to several years to induce rapid elongation of young growth of California redbud (see Other Uses) [1,2,4,5,6]. They also actively burned to keep down shrubs and trees and maintain an open, park-like woodland that aided hunting and favored certain food crops . Fire exclusion policies were implemented as European settlers entered the area in the late 19th century, again altering the chaparral and oak woodland communities [3,4]. With so much historical human interference in the oak woodlands and chaparral of California, gauging the historic or presettlement fire return interval in these communities is difficult and often debated. In a review by Keeley , evidence is offered that fire frequency in California chaparral has increased, not decreased, due to human-caused accidental fires (see Fire Management Considerations).
In oak woodlands, California redbud is often found in canyon live oak (Quercus chrysolepis), blue oak-gray pine (Q. douglasii-Pinus sabiniana), and interior live oak (Q. wislizenii) community types. The fire return interval in these communities is from <35 to <100 years . The fire return interval of stand-replacement fires in California chaparral varies, depending upon species composition. In reviews, Keeley and Keeley [41,43] stated that modal frequency of stand-replacement fires in California chaparral ranges from 20 to 30 years, and Paysen and others  reported fire return intervals ranging from less than 35 years to about every 100 years. Relatively long fire-return intervals are typical of chaparral dominated by obligate seeding species such as waveyleaf ceanothus (Ceanothus foliosus) , while relatively short fire-return intervals favor spouting chaparral species such as chamise [41,43].
The following table provides fire return intervals for plant communities and ecosystems where California redbud is important. Find 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)|
|California chaparral||Adenostoma and/or Arctostaphylos spp.||<35 to <100|
|sagebrush steppe||Artemisia tridentata/Pseudoroegneria spicata||20-70|
|coastal sagebrush||Artemisia californica||<35 to <100|
|grama-galleta steppe||Bouteloua gracilis-Pleuraphis jamesii||<35 to <100|
|blue grama-tobosa prairie||Bouteloua gracilis-Pleuraphis mutica||<35 to <100|
|California montane chaparral||Ceanothus and/or Arctostaphylos spp.||50-100 |
|curlleaf mountain-mahogany*||Cercocarpus ledifolius||13-1,000 [9,66]|
|mountain-mahogany-Gambel oak scrub||Cercocarpus ledifolius-Quercus gambelii||<35 to <100|
|Arizona cypress||Cupressus arizonica||<35 to 200|
|western juniper||Juniperus occidentalis||20-70 |
|pine-cypress forest||Pinus-Cupressus spp.||9-63 [7,70,74]|
|pinyon-juniper||Pinus-Juniperus spp.||<35 |
|Colorado pinyon||Pinus edulis||10-400+ [28,31,41,57]|
|Jeffrey pine||Pinus jeffreyi||5-30|
|Pacific ponderosa pine*||Pinus ponderosa var. ponderosa||1-47 |
|interior ponderosa pine*||Pinus ponderosa var. scopulorum||2-30 [8,10,47]|
|galleta-threeawn shrubsteppe||Pleuraphis jamesii-Aristida purpurea||<35 to <100 |
|California mixed evergreen||Pseudotsuga menziesii var. menziesii-Lithocarpus densiflorus-Arbutus menziesii||<35|
|California oakwoods||Quercus spp.||<35 |
|oak-juniper woodland (Southwest)||Quercus-Juniperus spp.||<35 to <200 |
|coast live oak||Quercus agrifolia||2-75 |
|canyon live oak||Quercus chrysolepis||<35 to 200|
|blue oak-foothills pine||Quercus douglasii-P. sabiniana||<35|
|Oregon white oak||Quercus garryana||<35 |
|California black oak||Quercus kelloggii||5-30 |
|interior live oak||Quercus wislizenii||<35 |
While there is little scientific information regarding California redbud's response to fire, Native Americans in the Sierra Nevada burned California redbud every several years, or even annually, to promote growth of young sprouts (see Other Uses) [1,2,3,4,5,6]. Further, a summer prescription fire in an interior live oak-gray pine community promoted California redbud sprouting or establishment from seed in postfire years 1, 2, and 3 . This suggests that fire promotes California redbud sprouting.
With such a dearth of information regarding California redbud response to fire, further fire research is sorely needed on this plant species.DISCUSSION AND QUALIFICATION OF PLANT RESPONSE:
|Preproject 1986||Postpreparation 1987||Postfire month 2||Postfire year 1||Postfire year 2||Postfire year 8|
Palatability/nutritional value: No information is available on this topic.
Cover value: Currently (2006) there is no literature addressing the cover value of California redbud. However, given its height [35,54,55,76] and arching canopy [68,72], it likely provides cover for a variety of mammal and bird species.VALUE FOR REHABILITATION OF DISTURBED SITES:
There is 1 California redbud cultivar ('common') available .OTHER USES:
California redbud is often used as a landscaping ornamental [11,20,72].OTHER MANAGEMENT CONSIDERATIONS:
Insects: The red humped caterpillar is a common defoliator of California redbud plants in California [17,52,58,60,61]. The larvae of red humped caterpillars can consume an average of 0.4 inch˛ of California redbud foliage per day . Bacillus thuringiensis, an insecticidal bacterium, can control red humped caterpillar larvae [17,17,58,60,61].
Bacillus thuringiensis is also an effective deterrent for the fruit tree leafroller, which causes serious leaf defoliation in California redbud plants .Fungus: California redbud is highly susceptible to a fungal canker caused by Botryosphaeria ribis and B. dothidea [62,65].
1. Anderson, M. Kat. 1991. California Indian horticulture: Management and use of redbud by the southern Sierra Miwok. Journal of Ethnobiology. 11(1): 145-157. 
2. Anderson, M. Kat. 1996. Tending the wilderness. Restoration & Management Notes. 14(2): 154-166. 
3. Anderson, M. Kat. 1997. California's endangered peoples and endangered ecosystems. American Indian Culture and Research Journal. 21(3): 7-31. 
4. Anderson, M. Kat. 1999. The fire, pruning, and coppice management of temperate ecosystems for basketry material by California Indian tribes. Human Ecology. 27(1): 79-113. 
5. Anderson, M. Kat; Moratto, Michael J. 1996. Native American land-use practices and ecological impacts. In: Status of the Sierra Nevada. Sierra Nevada Ecosystem Project: Final report to Congress. Volume II: Assessments and scientific basis for management options. Wildland Resources Center Report No. 37. Davis, CA: University of California, Centers for Water and Wildland Resources: 187-206. 
6. Anderson, Marion Kathleen. 1993. The experimental approach to assessment of the potential ecological effects of horticultural practices by indigenous peoples on California wildlands. Berkeley, CA: University of California. 211 p. Dissertation. 
7. Armstrong, Wayne P. 1966. Ecological and taxonomic relationships of Cupressus in southern California. Los Angles, CA: California State College. 129 p. Thesis. 
8. 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. 
9. Arno, Stephen F.; Wilson, Andrew E. 1986. Dating past fires in curlleaf mountain-mahogany communities. Journal of Range Management. 39(3): 241-243. 
10. 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. 
11. Banner, Valerie A.; Stein, William I. 2003. Cercis L. redbud. Bonner, Franklin T., tech. coord. Woody plant seed manual. Washington, DC: U.S. Department of Agriculture, Forest Service (Producer). Available: http://www.nsl.fs.fed.us/wpsm/Cercis.pdf [2006, August 2]. 
12. Barrett, Reginald H. 1983. Food habits of coyotes, Canis latrans, in eastern Tehama County, California. California Fish and Game. 69(3): 184-186. 
13. Bennett, Peter S.; Kunzmann, Michael R.; Johnson, R. Roy. 1989. Relative nature of wetlands: riparian and vegetational considerations. In: Abell, Dana L., technical coordinator. Protection, management, and restoration for the 1990's: Proceedings of the California riparian systems conference; 1988 September 22-24; Davis, CA. Gen. Tech. Rep. PSW-110. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station: 140-142. 
14. 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. 
15. Bonnicksen, Thomas M. 2000. Fire masters. In: Bonnicksen, Thomas M. America's ancient forests: From the Ice Age to the Age of Discovery. New York: John Wiley & Sons, Inc: 143-216. 
16. Brand, Richard J.; Pinnock, Dudley E.; Jackson, Kirby L.; Milstead, James E. 1975. Methods for assessing field persistence of Bacillus thuringiensis spores. Journal of Invertebrate Pathology. 25(2): 199-208. 
17. Brand, Richard J.; Pinnock, Dudley E.; Jackson, Kirby L.; Milstead, James E. 1976. Viable spore count as an index of effective dose of Bacillus thuringiensis. Journal of the Invertebrate Pathology. 27(2): 141-148. 
18. Calkin, Howard W.; Pearcy, Robert W. 1984. Leaf conductance and transpiration, and water relations of evergreen and deciduous perennials co-occurring in a moist chaparral site. Plant, Cell and Environment. 7(5): 339-346. 
19. Castetter, Edward F. 1935. Ethnobiological studies in the American Southwest. Biological Series No. 4: Volume 1. Albuquerque, NM: University of New Mexico. 62 p. 
20. Ciesla, Bill. 1981. The outriders of spring: Redbud. American Forests. 87(4): 22-27. 
21. Clover, Elzada U.; Jotter, Lois. 1944. Floristic studies in the Canyon of the Colorado and tributaries. The American Midland Naturalist. 32(3): 591-642. 
22. Cooper, William Skinner. 1922. The broad-sclerophyll vegetation of California: an ecological study of the chaparral and its related communities. Publ. No. 319. Washington, DC: The Carnegie Institution of Washington. 145 p. 
23. DeBolt, Ann; Spurrier, Carol S. 2004. Seeds of success and the Millennium Seed Bank project. In: Hild, Ann L.; Shaw, Nancy L.; Meyer, Susan E.; Booth, D. Terrance; McArthur, E. Durant, compilers. Seed and soil dynamics in shrubland ecosystems: proceedings; 2002 August 12-16; Laramie, WY. Proceedings RMRS-P-31. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station: 100-108. 
24. Dobson, Heidi E. M. 1988. Survey of pollen and pollenkitt lipids -- chemical cues to flower visitors? American Journal of Botany. 75(2): 170-182. 
25. Elmore, Francis H. 1944. Ethnobotany of the Navajo. Monograph Series: 1(7). Albuquerque, NM: University of New Mexico. 136 p. 
26. Erdman, Kimball S. 1961. Distribution of the native trees of Utah. Brigham Young University Science Bulletin: Biological Series. 11: 1-34. 
27. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. 
28. Floyd, M. Lisa; Romme, William H.; Hanna, David D. 2000. Fire history and vegetation pattern in Mesa Verde National Park, Colorado, USA. Ecological Applications. 10(6): 1666-1680. 
29. Frost, William E. 1989. The Ellis Ranch Project: a case study in controlled burning. No. 891002. Fresno, CA: California Agricultural Technology Institute; San Joaquin Experimental Range. 11 p. 
30. 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. 
31. Gottfried, Gerald J.; Swetnam, Thomas W.; Allen, Craig D.; Betancourt, Julio L.; Chung-MacCoubrey, Alice L. 1995. Pinyon-juniper woodlands. In: Finch, Deborah M.; Tainter, Joseph A., eds. Ecology, diversity, and sustainability of the Middle Rio Grande Basin. Gen. Tech. Rep. RM-GTR-268. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station: 95-132. 
32. Graves, George W. 1932. Ecological relationships of Pinus sabiniana. Botanical Gazette. 94(1): 106-133. 
33. Greenlee, Jason M.; Langenheim, Jean H. 1990. Historic fire regimes and their relation to vegetation patterns in the Monterey Bay area of California. The American Midland Naturalist. 124(2): 239-253. 
34. Heit, C. E. 1971. Propagation from seed. Part 22: testing and growing western desert and mountain shrub species. American Nurseryman. 133(10): 10-12, 76-89. 
35. Hickman, James C., ed. 1993. The Jepson manual: Higher plants of California. Berkeley, CA: University of California Press. 1400 p. 
36. Hopkins, Milton. 1942. Cercis in North America. Rhodora. 44(522): 193-211. 
37. Juhren, Gustaf. 1949. Erosion control on Palomar Mt. Observatory Road. Journal of Forestry. 47(6): 463-466. 
38. 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]. 
39. Kartesz, John Thomas. 1988. A flora of Nevada. Reno, NV: University of Nevada. 1729 p. [In 2 volumes]. Dissertation. 
40. Kearney, Thomas H.; Peebles, Robert H.; Howell, John Thomas; McClintock, Elizabeth. 1960. Arizona flora. 2nd ed. Berkeley, CA: University of California Press. 1085 p. 
41. Keeley, Jon E. 1981. Reproductive cycles and fire regimes. In: Mooney, H. A.; Bonnicksen, T. M.; Christensen, N. L.; Lotan, J. E.; Reiners, W. A., tech. coords. 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: 231-277. 
42. Keeley, Jon E. 2001. Fire and invasive species in Mediterranean-climate ecosystems in California. In: Galley, Krista E. M.; Wilson, Tyrone P., eds. Proceedings of the invasive species workshop: The role of fire in the control and spread of invasive species; Fire conference 2000: the first national congress on fire ecology, prevention, and management; 2000 November 27 - December 1; San Diego, CA. Misc. Publ. No. 11. Tallahassee, FL: Tall Timbers Research Station: 81-94. 
43. Keeley, Jon E.; Keeley, Sterling C. 1986. Chaparral and wildfires. Fremontia. 14(3): 18-21. 
44. Keeley, Melanie. 2005. Propagation protocol for California redbud (Cercis orbiculata Greene). Native Plants Journal. 6(2): 131. 
45. Krochmal, A.; Paur, S.; Duisberg, P. 1954. Useful native plants in the American southwestern deserts. Economic Botany. 8: 3-20. 
46. 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. 
47. 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., tech. coords. 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. 
48. Liang, Yan; Harris, Jeanne M. 2005. Response of root branching to abscisic acid is correlated with nodule formation both in legumes and nonlegumes. American Journal of Botany. 92(10): 1675-1683. 
49. Little, Elbert L., Jr. 1950. Southwestern trees: A guide to the native species of New Mexico and Arizona. Agricultural Handbook 9. Washington, DC: U.S. Department of Agriculture, Forest Service. 109 p. 
50. McDougald, Neil K.; Frost, William E. 1997. Assessment of a prescribed burning project: 1987-1995. In: Pillsbury, Norman H.; Verner, Jared; Tietje, William D., technical coordinators. Proceedings of a symposium on oak woodlands: ecology, management, and urban interface issues; 1996 March 19-22; San Luis Obispo, CA. Gen. Tech. Rep. PSW-GTR-160. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station: 671-678. 
51. Menke, John W.; Villasenor, Ricardo. 1977. The California Mediterranean ecosystem and its management. In: Mooney, Harold A.; Conrad, C. Eugene, technical coordinators. Proceedings of the symposium on the environmental consequences of fire and fuel management in Mediterranean ecosystems; 1977 August 1-5; Palo Alto, CA. Gen. Tech. Rep. WO-3. Washington, DC: U.S. Department of Agriculture, Forest Service: 257-270. 
52. Milstead, James E. 1980. Pathophysiological influences of the Heterorhabditis bacteriophora complex on fifth-instar larvae of the red humped caterpillar Schizura concinna: changes in feeding rate, larval weight, and frass production. Journal of Invertebrate Pathology. 35(3): 260-264. 
53. Mirov, N. T. 1936. Germination behavior of some California plants. Ecology. 17(4): 667-672. 
54. Munz, Philip A. 1973. A California flora and supplement. Berkeley, CA: University of California Press. 1905 p. 
55. Munz, Philip A. 1974. A flora of southern California. Berkeley, CA: University of California Press. 1086 p. 
56. Patey, Katherine J.; Wishner, Carl; Gibson, Joseph G. 1991. Tapo Canyon Creek riparian habitat restoration plan. Restoration & Management Notes. 9(1): 47-48. 
57. Paysen, Timothy E.; Ansley, R. James; Brown, James K.; Gottfried, Gerald J.; Haase, Sally M.; Harrington, Michael G.; Narog, Marcia G.; Sackett, Stephen S.; Wilson, Ruth C. 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. 
58. Pinnock, D. E.; Brand, R. J.; Milstead, J. E.; Kirby, M. E.; Coe, N. F. 1978. Development of a model for prediction of target insect mortality following field application of a Bacillus thuringiensis formulation. Journal of Invertebrate Pathology. 31(1): 31-36. 
59. Pinnock, D. E.; Milstead, J. E. 1978. Microbial control of the fruit tree leafroller, Archips argyrospila [Lep.: Tortricidae] in California. Entomophaga. 23(3): 203-206. 
60. Pinnock, D. E.; Milstead, J. E.; Coe, N. F.; Brand, R. J. 1974. The effectiveness of Bacillus thuringiensis formulations for the control of larvae of Schizura concinna on Cercis occidentalis trees in California. Entomophaga. 19(3): 221-227. 
61. Pinnock, Dudley E.; Brand, Richard J.; Milstead, James E.; Jackson, Kirby L. 1975. Effect of three species on the coverage and field persistence of Bacillus thuringiensis spores. Journal of Invertebrate Pathology. 25(2): 209-214. 
62. Pooler, M. R.; Jacobs, K. A.; Kramer, M. 2002. Differential resistance to Botryosphaeria ribis among Cercis taxa. Plant Disease. 86(8): 880-882. 
63. Raunkiaer, C. 1934. The life forms of plants and statistical plant geography. Oxford: Clarendon Press. 632 p. 
64. Sampson, Arthur W.; Jespersen, Beryl S. 1963. California range brushlands and browse plants. Berkeley, CA: University of California, Division of Agricultural Sciences; California Agricultural Experiment Station, Extension Service. 162 p. 
65. Santamour, Frank S., Jr.; Riedel, Louise G. H. 1995. Susceptibility of redbuds (Cercis) to root-knot nematodes. Journal of Arboriculture. 21(1): 37-40. 
66. Schultz, Brad W. 1987. Ecology of curlleaf mountain mahogany (Cercocarpus ledifolius) in western and central Nevada: population structure and dynamics. Reno, NV: University of Nevada. 111 p. Thesis. 
67. Shiflet, Thomas N., ed. 1994. Rangeland cover types of the United States. Denver, CO: Society for Range Management. 152 p. 
68. Smith, Nevin. 1986. Growing natives: more from the chaparral. Fremontia. 14(3): 34-35. 
69. 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. 
70. Swetnam, Thomas W.; Baisan, Christopher H.; Caprio, Anthony C.; Brown, Peter M. 1992. Fire history in a Mexican oak-pine woodland and adjacent montane conifer gallery forest in southeastern Arizona. In: Ffolliott, Peter F.; Gottfried, Gerald J.; Bennett, Duane A.; Hernandez C., Victor Manuel; Ortega-Rubio, Alfred; Hamre, R. H., tech. coords. Ecology and management of oak and associated woodlands: perspectives in the southwestern United States and northern Mexico: Proceedings; 1992 April 27-30; Sierra Vista, AZ. Gen. Tech. Rep. RM-218. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station: 165-173. 
71. U.S. Department of Agriculture, Natural Resources Conservation Service, Tucson Plant Materials Center. 2001. Commercial sources of conservation plant materials, [Online]. Available: http://plant-materials.nrcs.usda.gov/pubs/azpmsarseedlist0501.pdf [2003, August 25]. 
72. U.S. Department of Agriculture, Natural Resources Conservation Service. 2006. PLANTS database (2006), [Online]. Available: http://plants.usda.gov/. 
73. Vankat, John L.; Major, Jack. 1978. Vegetation changes in Sequoia National Park, California. Journal of Biogeography. 5: 377-402. 
74. Vogl, Richard J.; Armstrong, Wayne P.; White, Keith L.; Cole, Kenneth L. 1977. The closed-cone pines and cypress. In: Barbour, Michael G.; Major, Jack, eds. Terrestrial vegetation of California. New York: John Wiley and Sons: 295-358. 
75. Walters, M. Alice; Teskey, Robert O.; Hinckley, Thomas M. 1980. Impact of water level changes on woody riparian and wetland communities. Volume VII: Mediterranean Region; Western Arid and Semi-Arid Region. Biological Services Program: FWS/OBS-78/93. Washington, DC: U.S. Department of the Interior, Fish and Wildlife Service. 84 p. 
76. 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.